Wreck validation until we can assess ecosystem :/.

[apt.git] / apt-pkg / acquire-item.cc

diff --git a/apt-pkg/acquire-item.cc b/apt-pkg/acquire-item.cc
index 834776404e5cb9defbf774d331fb6b79292e8517..663452b9f1c92451c72ac5008f46e4c0c83411f4 100644 (file)
--- a/apt-pkg/acquire-item.cc
+++ b/apt-pkg/acquire-item.cc
@@ -45,13 +45,15 @@
 #include <stdio.h>
 #include <ctime>
 #include <sstream>
 #include <stdio.h>
 #include <ctime>
 #include <sstream>

+#include <numeric>
+#include <random>

 
 #include <apti18n.h>
                                                                        /*}}}*/
 
 using namespace std;
 
 
 #include <apti18n.h>
                                                                        /*}}}*/
 
 using namespace std;
 

-static void printHashSumComparision(std::string const &URI, HashStringList const &Expected, HashStringList const &Actual) /*{{{*/
+static void printHashSumComparison(std::string const &URI, HashStringList const &Expected, HashStringList const &Actual) /*{{{*/

 {
    if (_config->FindB("Debug::Acquire::HashSumMismatch", false) == false)
       return;
 {
    if (_config->FindB("Debug::Acquire::HashSumMismatch", false) == false)
       return;


@@ -85,32 +87,16 @@ static std::string GetKeepCompressedFileName(std::string file, IndexTarget const
    if (Target.KeepCompressed == false)
       return file;
 
    if (Target.KeepCompressed == false)
       return file;
 

-   std::string const CompressionTypes = Target.Option(IndexTarget::COMPRESSIONTYPES);
-   if (CompressionTypes.empty() == false)
+   std::string const KeepCompressedAs = Target.Option(IndexTarget::KEEPCOMPRESSEDAS);
+   if (KeepCompressedAs.empty() == false)

    {
    {

-      std::string const ext = CompressionTypes.substr(0, CompressionTypes.find(' '));
+      std::string const ext = KeepCompressedAs.substr(0, KeepCompressedAs.find(' '));

       if (ext != "uncompressed")
         file.append(".").append(ext);
    }
    return file;
 }
                                                                        /*}}}*/
       if (ext != "uncompressed")
         file.append(".").append(ext);
    }
    return file;
 }
                                                                        /*}}}*/

-static std::string GetCompressedFileName(IndexTarget const &Target, std::string const &Name, std::string const &Ext) /*{{{*/
-{
-   if (Ext.empty() || Ext == "uncompressed")
-      return Name;
-
-   // do not reverify cdrom sources as apt-cdrom may rewrite the Packages
-   // file when its doing the indexcopy
-   if (Target.URI.substr(0,6) == "cdrom:")
-      return Name;
-
-   // adjust DestFile if its compressed on disk
-   if (Target.KeepCompressed == true)
-      return Name + '.' + Ext;
-   return Name;
-}
-                                                                       /*}}}*/

 static std::string GetMergeDiffsPatchFileName(std::string const &Final, std::string const &Patch)/*{{{*/
 {
    // rred expects the patch as $FinalFile.ed.$patchname.gz
 static std::string GetMergeDiffsPatchFileName(std::string const &Final, std::string const &Patch)/*{{{*/
 {
    // rred expects the patch as $FinalFile.ed.$patchname.gz


@@ -123,66 +109,168 @@ static std::string GetDiffsPatchFileName(std::string const &Final)       /*{{{*/
    return Final + ".ed";
 }
                                                                        /*}}}*/
    return Final + ".ed";
 }
                                                                        /*}}}*/

-static bool BootstrapPDiffWith(std::string const &PartialFile, std::string const &FinalFile, IndexTarget const &Target)/*{{{*/
+static std::string GetExistingFilename(std::string const &File)                /*{{{*/

 {
 {

-   // patching needs to be bootstrapped with the 'old' version
-   std::vector<std::string> types = VectorizeString(Target.Option(IndexTarget::COMPRESSIONTYPES), ' ');
-   auto typeItr = types.cbegin();
-   for (; typeItr != types.cend(); ++typeItr)
+   if (RealFileExists(File))
+      return File;
+   for (auto const &type : APT::Configuration::getCompressorExtensions())

    {
    {

-      std::string Final = FinalFile;
-      if (*typeItr != "uncompressed")
-        Final.append(".").append(*typeItr);
-      if (RealFileExists(Final) == false)
-        continue;
-      std::string Partial = PartialFile;
-      if (*typeItr != "uncompressed")
-        Partial.append(".").append(*typeItr);
-      if (FileExists(Partial.c_str()) == true)
-        return true;
-      if (symlink(Final.c_str(), Partial.c_str()) != 0)
-        return false;
-      break;
+      std::string const Final = File + type;
+      if (RealFileExists(Final))
+        return Final;

    }
    }

-   return typeItr != types.cend();
+   return "";
+}
+                                                                       /*}}}*/
+static std::string GetDiffIndexFileName(std::string const &Name)       /*{{{*/
+{
+   return Name + ".diff/Index";
+}
+                                                                       /*}}}*/
+static std::string GetDiffIndexURI(IndexTarget const &Target)          /*{{{*/
+{
+   return Target.URI + ".diff/Index";

 }
                                                                        /*}}}*/
 
 }
                                                                        /*}}}*/
 

-static bool MessageInsecureRepository(bool const isError, std::string const &msg)/*{{{*/
+static void ReportMirrorFailureToCentral(pkgAcquire::Item const &I, std::string const &FailCode, std::string const &Details)/*{{{*/

 {
 {

+   // we only act if a mirror was used at all
+   if(I.UsedMirror.empty())
+      return;
+#if 0
+   std::cerr << "\nReportMirrorFailure: "
+            << UsedMirror
+            << " Uri: " << DescURI()
+            << " FailCode: "
+            << FailCode << std::endl;
+#endif
+   string const report = _config->Find("Methods::Mirror::ProblemReporting",
+                                LIBEXEC_DIR "/apt-report-mirror-failure");
+   if(!FileExists(report))
+      return;
+
+   std::vector<char const*> const Args = {
+      report.c_str(),
+      I.UsedMirror.c_str(),
+      I.DescURI().c_str(),
+      FailCode.c_str(),
+      Details.c_str(),
+      NULL
+   };
+
+   pid_t pid = ExecFork();
+   if(pid < 0)
+   {
+      _error->Error("ReportMirrorFailure Fork failed");
+      return;
+   }
+   else if(pid == 0)
+   {
+      execvp(Args[0], (char**)Args.data());
+      std::cerr << "Could not exec " << Args[0] << std::endl;
+      _exit(100);
+   }
+   if(!ExecWait(pid, "report-mirror-failure"))
+      _error->Warning("Couldn't report problem to '%s'", report.c_str());
+}
+                                                                       /*}}}*/
+
+static APT_NONNULL(2) bool MessageInsecureRepository(bool const isError, char const * const msg, std::string const &repo)/*{{{*/
+{
+   std::string m;
+   strprintf(m, msg, repo.c_str());

    if (isError)
    {
    if (isError)
    {

-      _error->Error("%s", msg.c_str());
-      _error->Notice("%s", _("Updating such a repository securily is impossible and therefore disabled by default."));
+      _error->Error("%s", m.c_str());
+      _error->Notice("%s", _("Updating from such a repository can't be done securely, and is therefore disabled by default."));

    }
    else
    {
    }
    else
    {

-      _error->Warning("%s", msg.c_str());
-      _error->Notice("%s", _("Data from such a repository can not be authenticated and is therefore potentially dangerous to use."));
+      _error->Warning("%s", m.c_str());
+      _error->Notice("%s", _("Data from such a repository can't be authenticated and is therefore potentially dangerous to use."));

    }
    _error->Notice("%s", _("See apt-secure(8) manpage for repository creation and user configuration details."));
    return false;
 }
    }
    _error->Notice("%s", _("See apt-secure(8) manpage for repository creation and user configuration details."));
    return false;
 }

-static bool MessageInsecureRepository(bool const isError, char const * const msg, std::string const &repo)
+                                                                       /*}}}*/
+// AllowInsecureRepositories                                           /*{{{*/
+enum class InsecureType { UNSIGNED, WEAK, NORELEASE };
+static bool TargetIsAllowedToBe(IndexTarget const &Target, InsecureType const type)

 {
 {

-   std::string m;
-   strprintf(m, msg, repo.c_str());
-   return MessageInsecureRepository(isError, m);
+   if (_config->FindB("Acquire::AllowInsecureRepositories"))
+      return true;
+
+   if (Target.OptionBool(IndexTarget::ALLOW_INSECURE))
+      return true;
+
+   switch (type)
+   {
+      case InsecureType::UNSIGNED: break;
+      case InsecureType::NORELEASE: break;
+      case InsecureType::WEAK:
+        if (_config->FindB("Acquire::AllowWeakRepositories"))
+           return true;
+        if (Target.OptionBool(IndexTarget::ALLOW_WEAK))
+           return true;
+        break;
+   }
+   return false;

 }
 }

-                                                                       /*}}}*/
-static bool AllowInsecureRepositories(char const * const msg, std::string const &repo,/*{{{*/
+static bool APT_NONNULL(3, 4, 5) AllowInsecureRepositories(InsecureType const msg, std::string const &repo,

       metaIndex const * const MetaIndexParser, pkgAcqMetaClearSig * const TransactionManager, pkgAcquire::Item * const I)
 {
       metaIndex const * const MetaIndexParser, pkgAcqMetaClearSig * const TransactionManager, pkgAcquire::Item * const I)
 {

+   // we skip weak downgrades as its unlikely that a repository gets really weaker –
+   // its more realistic that apt got pickier in a newer version
+   if (msg != InsecureType::WEAK)
+   {
+      std::string const FinalInRelease = TransactionManager->GetFinalFilename();
+      std::string const FinalReleasegpg = FinalInRelease.substr(0, FinalInRelease.length() - strlen("InRelease")) + "Release.gpg";
+      if (RealFileExists(FinalReleasegpg) || RealFileExists(FinalInRelease))
+      {
+        char const * msgstr = nullptr;
+        switch (msg)
+        {
+           case InsecureType::UNSIGNED: msgstr = _("The repository '%s' is no longer signed."); break;
+           case InsecureType::NORELEASE: msgstr = _("The repository '%s' does no longer have a Release file."); break;
+           case InsecureType::WEAK: /* unreachable */ break;
+        }
+        if (_config->FindB("Acquire::AllowDowngradeToInsecureRepositories") ||
+              TransactionManager->Target.OptionBool(IndexTarget::ALLOW_DOWNGRADE_TO_INSECURE))
+        {
+           // meh, the users wants to take risks (we still mark the packages
+           // from this repository as unauthenticated)
+           _error->Warning(msgstr, repo.c_str());
+           _error->Warning(_("This is normally not allowed, but the option "
+                    "Acquire::AllowDowngradeToInsecureRepositories was "
+                    "given to override it."));
+        } else {
+           MessageInsecureRepository(true, msgstr, repo);
+           TransactionManager->AbortTransaction();
+           I->Status = pkgAcquire::Item::StatError;
+           return false;
+        }
+      }
+   }
+

    if(MetaIndexParser->GetTrusted() == metaIndex::TRI_YES)
       return true;
 
    if(MetaIndexParser->GetTrusted() == metaIndex::TRI_YES)
       return true;
 

-   if (_config->FindB("Acquire::AllowInsecureRepositories") == true)
+   char const * msgstr = nullptr;
+   switch (msg)
+   {
+      case InsecureType::UNSIGNED: msgstr = _("The repository '%s' is not signed."); break;
+      case InsecureType::NORELEASE: msgstr = _("The repository '%s' does not have a Release file."); break;
+      case InsecureType::WEAK: msgstr = _("The repository '%s' provides only weak security information."); break;
+   }
+
+   if (TargetIsAllowedToBe(TransactionManager->Target, msg) == true)

    {
    {

-      MessageInsecureRepository(false, msg, repo);
+      //MessageInsecureRepository(false, msgstr, repo);

       return true;
    }
 
       return true;
    }
 

-   MessageInsecureRepository(true, msg, repo);
+   MessageInsecureRepository(true, msgstr, repo);

    TransactionManager->AbortTransaction();
    I->Status = pkgAcquire::Item::StatError;
    return false;
    TransactionManager->AbortTransaction();
    I->Status = pkgAcquire::Item::StatError;
    return false;


@@ -212,8 +300,20 @@ APT_CONST bool pkgAcqTransactionItem::HashesRequired() const
       we can at least trust them for integrity of the download itself.
       Only repositories without a Release file can (obviously) not have
       hashes – and they are very uncommon and strongly discouraged */
       we can at least trust them for integrity of the download itself.
       Only repositories without a Release file can (obviously) not have
       hashes – and they are very uncommon and strongly discouraged */

-   return TransactionManager->MetaIndexParser != NULL &&
-      TransactionManager->MetaIndexParser->GetLoadedSuccessfully() != metaIndex::TRI_UNSET;
+   if (TransactionManager->MetaIndexParser->GetLoadedSuccessfully() != metaIndex::TRI_YES)
+      return false;
+   if (TargetIsAllowedToBe(Target, InsecureType::WEAK))
+   {
+      /* If we allow weak hashes, we check that we have some (weak) and then
+         declare hashes not needed. That will tip us in the right direction
+        as if hashes exist, they will be used, even if not required */
+      auto const hsl = GetExpectedHashes();
+      if (hsl.usable())
+        return true;
+      if (hsl.empty() == false)
+        return false;
+   }
+   return true;

 }
 HashStringList pkgAcqTransactionItem::GetExpectedHashes() const
 {
 }
 HashStringList pkgAcqTransactionItem::GetExpectedHashes() const
 {


@@ -232,12 +332,12 @@ HashStringList pkgAcqMetaBase::GetExpectedHashes() const
 
 APT_CONST bool pkgAcqIndexDiffs::HashesRequired() const
 {
 
 APT_CONST bool pkgAcqIndexDiffs::HashesRequired() const
 {

-   /* We don't always have the diff of the downloaded pdiff file.
-      What we have for sure is hashes for the uncompressed file,
-      but rred uncompresses them on the fly while parsing, so not handled here.
-      Hashes are (also) checked while searching for (next) patch to apply. */
+   /* We can't check hashes of rred result as we don't know what the
+      hash of the file will be. We just know the hash of the patch(es),
+      the hash of the file they will apply on and the hash of the resulting
+      file. */

    if (State == StateFetchDiff)
    if (State == StateFetchDiff)

-      return available_patches[0].download_hashes.empty() == false;
+      return true;

    return false;
 }
 HashStringList pkgAcqIndexDiffs::GetExpectedHashes() const
    return false;
 }
 HashStringList pkgAcqIndexDiffs::GetExpectedHashes() const


@@ -253,7 +353,7 @@ APT_CONST bool pkgAcqIndexMergeDiffs::HashesRequired() const
       we can check the rred result after all patches are applied as
       we know the expected result rather than potentially apply more patches */
    if (State == StateFetchDiff)
       we can check the rred result after all patches are applied as
       we know the expected result rather than potentially apply more patches */
    if (State == StateFetchDiff)

-      return patch.download_hashes.empty() == false;
+      return true;

    return State == StateApplyDiff;
 }
 HashStringList pkgAcqIndexMergeDiffs::GetExpectedHashes() const
    return State == StateApplyDiff;
 }
 HashStringList pkgAcqIndexMergeDiffs::GetExpectedHashes() const


@@ -297,14 +397,34 @@ bool pkgAcquire::Item::QueueURI(pkgAcquire::ItemDesc &Item)
    for a hashsum mismatch to happen which helps nobody) */
 bool pkgAcqTransactionItem::QueueURI(pkgAcquire::ItemDesc &Item)
 {
    for a hashsum mismatch to happen which helps nobody) */
 bool pkgAcqTransactionItem::QueueURI(pkgAcquire::ItemDesc &Item)
 {

+   if (TransactionManager->State != TransactionStarted)
+   {
+      if (_config->FindB("Debug::Acquire::Transaction", false))
+        std::clog << "Skip " << Target.URI << " as transaction was already dealt with!" << std::endl;
+      return false;
+   }

    std::string const FinalFile = GetFinalFilename();
    std::string const FinalFile = GetFinalFilename();

-   if (TransactionManager != NULL && TransactionManager->IMSHit == true &&
-        FileExists(FinalFile) == true)
+   if (TransactionManager->IMSHit == true && FileExists(FinalFile) == true)

    {
       PartialFile = DestFile = FinalFile;
       Status = StatDone;
       return false;
    }
    {
       PartialFile = DestFile = FinalFile;
       Status = StatDone;
       return false;
    }

+   // If we got the InRelease file via a mirror, pick all indexes directly from this mirror, too
+   if (TransactionManager->BaseURI.empty() == false && UsedMirror.empty() &&
+        URI::SiteOnly(Item.URI) != URI::SiteOnly(TransactionManager->BaseURI))
+   {
+      // this ensures we rewrite only once and only the first step
+      auto const OldBaseURI = Target.Option(IndexTarget::BASE_URI);
+      if (OldBaseURI.empty() == false && APT::String::Startswith(Item.URI, OldBaseURI))
+      {
+        auto const ExtraPath = Item.URI.substr(OldBaseURI.length());
+        Item.URI = flCombine(TransactionManager->BaseURI, ExtraPath);
+        UsedMirror = TransactionManager->UsedMirror;
+        if (Item.Description.find(" ") != string::npos)
+           Item.Description.replace(0, Item.Description.find(" "), UsedMirror);
+      }
+   }

    return pkgAcquire::Item::QueueURI(Item);
 }
 /* The transition manager InRelease itself (or its older sisters-in-law
    return pkgAcquire::Item::QueueURI(Item);
 }
 /* The transition manager InRelease itself (or its older sisters-in-law


@@ -327,17 +447,21 @@ bool pkgAcqDiffIndex::QueueURI(pkgAcquire::ItemDesc &Item)
 // Acquire::Item::GetFinalFilename and specialisations for child classes       /*{{{*/
 std::string pkgAcquire::Item::GetFinalFilename() const
 {
 // Acquire::Item::GetFinalFilename and specialisations for child classes       /*{{{*/
 std::string pkgAcquire::Item::GetFinalFilename() const
 {

+   // Beware: Desc.URI is modified by redirections

    return GetFinalFileNameFromURI(Desc.URI);
 }
 std::string pkgAcqDiffIndex::GetFinalFilename() const
 {
    return GetFinalFileNameFromURI(Desc.URI);
 }
 std::string pkgAcqDiffIndex::GetFinalFilename() const
 {

-   // the logic we inherent from pkgAcqBaseIndex isn't what we need here
-   return pkgAcquire::Item::GetFinalFilename();
+   std::string const FinalFile = GetFinalFileNameFromURI(GetDiffIndexURI(Target));
+   // we don't want recompress, so lets keep whatever we got
+   if (CurrentCompressionExtension == "uncompressed")
+      return FinalFile;
+   return FinalFile + "." + CurrentCompressionExtension;

 }
 std::string pkgAcqIndex::GetFinalFilename() const
 {
    std::string const FinalFile = GetFinalFileNameFromURI(Target.URI);
 }
 std::string pkgAcqIndex::GetFinalFilename() const
 {
    std::string const FinalFile = GetFinalFileNameFromURI(Target.URI);

-   return GetCompressedFileName(Target, FinalFile, CurrentCompressionExtension);
+   return GetKeepCompressedFileName(FinalFile, Target);

 }
 std::string pkgAcqMetaSig::GetFinalFilename() const
 {
 }
 std::string pkgAcqMetaSig::GetFinalFilename() const
 {


@@ -369,7 +493,10 @@ std::string pkgAcqIndex::GetMetaKey() const
 }
 std::string pkgAcqDiffIndex::GetMetaKey() const
 {
 }
 std::string pkgAcqDiffIndex::GetMetaKey() const
 {

-   return Target.MetaKey + ".diff/Index";
+   auto const metakey = GetDiffIndexFileName(Target.MetaKey);
+   if (CurrentCompressionExtension == "uncompressed")
+      return metakey;
+   return metakey + "." + CurrentCompressionExtension;

 }
                                                                        /*}}}*/
 //pkgAcqTransactionItem::TransactionState and specialisations for child classes        /*{{{*/
 }
                                                                        /*}}}*/
 //pkgAcqTransactionItem::TransactionState and specialisations for child classes        /*{{{*/


@@ -378,6 +505,7 @@ bool pkgAcqTransactionItem::TransactionState(TransactionStates const state)
    bool const Debug = _config->FindB("Debug::Acquire::Transaction", false);
    switch(state)
    {
    bool const Debug = _config->FindB("Debug::Acquire::Transaction", false);
    switch(state)
    {

+      case TransactionStarted: _error->Fatal("Item %s changed to invalid transaction start state!", Target.URI.c_str()); break;

       case TransactionAbort:
         if(Debug == true)
            std::clog << "  Cancel: " << DestFile << std::endl;
       case TransactionAbort:
         if(Debug == true)
            std::clog << "  Cancel: " << DestFile << std::endl;


@@ -388,16 +516,66 @@ bool pkgAcqTransactionItem::TransactionState(TransactionStates const state)
         }
         break;
       case TransactionCommit:
         }
         break;
       case TransactionCommit:

-        if(PartialFile != "")
+        if(PartialFile.empty() == false)

         {
         {

-           if(Debug == true)
-              std::clog << "mv " << PartialFile << " -> "<< DestFile << " # " << DescURI() << std::endl;
+           bool sameFile = (PartialFile == DestFile);
+           // we use symlinks on IMS-Hit to avoid copies
+           if (RealFileExists(DestFile))
+           {
+              struct stat Buf;
+              if (lstat(PartialFile.c_str(), &Buf) != -1)
+              {
+                 if (S_ISLNK(Buf.st_mode) && Buf.st_size > 0)
+                 {
+                    char partial[Buf.st_size + 1];
+                    ssize_t const sp = readlink(PartialFile.c_str(), partial, Buf.st_size);
+                    if (sp == -1)
+                       _error->Errno("pkgAcqTransactionItem::TransactionState-sp", _("Failed to readlink %s"), PartialFile.c_str());
+                    else
+                    {
+                       partial[sp] = '\0';
+                       sameFile = (DestFile == partial);
+                    }
+                 }
+              }
+              else
+                 _error->Errno("pkgAcqTransactionItem::TransactionState-stat", _("Failed to stat %s"), PartialFile.c_str());
+           }
+           if (sameFile == false)
+           {
+              // ensure that even without lists-cleanup all compressions are nuked
+              std::string FinalFile = GetFinalFileNameFromURI(Target.URI);
+              if (FileExists(FinalFile))
+              {
+                 if(Debug == true)
+                    std::clog << "rm " << FinalFile << " # " << DescURI() << std::endl;
+                 if (RemoveFile("TransactionStates-Cleanup", FinalFile) == false)
+                    return false;
+              }
+              for (auto const &ext: APT::Configuration::getCompressorExtensions())
+              {
+                 auto const Final = FinalFile + ext;
+                 if (FileExists(Final))
+                 {
+                    if(Debug == true)
+                       std::clog << "rm " << Final << " # " << DescURI() << std::endl;
+                    if (RemoveFile("TransactionStates-Cleanup", Final) == false)
+                       return false;
+                 }
+              }
+              if(Debug == true)
+                 std::clog << "mv " << PartialFile << " -> "<< DestFile << " # " << DescURI() << std::endl;
+              if (Rename(PartialFile, DestFile) == false)
+                 return false;
+           }
+           else if(Debug == true)
+              std::clog << "keep " << PartialFile << " # " << DescURI() << std::endl;

 
 

-           Rename(PartialFile, DestFile);

         } else {
            if(Debug == true)
               std::clog << "rm " << DestFile << " # " << DescURI() << std::endl;
         } else {
            if(Debug == true)
               std::clog << "rm " << DestFile << " # " << DescURI() << std::endl;

-           RemoveFile("TransactionCommit", DestFile);
+           if (RemoveFile("TransItem::TransactionCommit", DestFile) == false)
+              return false;

         }
         break;
    }
         }
         break;
    }


@@ -417,18 +595,19 @@ bool pkgAcqIndex::TransactionState(TransactionStates const state)
 
    switch (state)
    {
 
    switch (state)
    {

+      case TransactionStarted: _error->Fatal("AcqIndex %s changed to invalid transaction start state!", Target.URI.c_str()); break;

       case TransactionAbort:
         if (Stage == STAGE_DECOMPRESS_AND_VERIFY)
         {
            // keep the compressed file, but drop the decompressed
            EraseFileName.clear();
       case TransactionAbort:
         if (Stage == STAGE_DECOMPRESS_AND_VERIFY)
         {
            // keep the compressed file, but drop the decompressed
            EraseFileName.clear();

-           if (PartialFile.empty() == false && flExtension(PartialFile) == "decomp")
+           if (PartialFile.empty() == false && flExtension(PartialFile) != CurrentCompressionExtension)

               RemoveFile("TransactionAbort", PartialFile);
         }
         break;
       case TransactionCommit:
         if (EraseFileName.empty() == false)
               RemoveFile("TransactionAbort", PartialFile);
         }
         break;
       case TransactionCommit:
         if (EraseFileName.empty() == false)

-           RemoveFile("TransactionCommit", EraseFileName);
+           RemoveFile("AcqIndex::TransactionCommit", EraseFileName);

         break;
    }
    return true;
         break;
    }
    return true;


@@ -440,6 +619,7 @@ bool pkgAcqDiffIndex::TransactionState(TransactionStates const state)
 
    switch (state)
    {
 
    switch (state)
    {

+      case TransactionStarted: _error->Fatal("Item %s changed to invalid transaction start state!", Target.URI.c_str()); break;

       case TransactionCommit:
         break;
       case TransactionAbort:
       case TransactionCommit:
         break;
       case TransactionAbort:


@@ -476,12 +656,52 @@ class APT_HIDDEN NoActionItem : public pkgAcquire::Item                   /*{{{*/
    }
 };
                                                                        /*}}}*/
    }
 };
                                                                        /*}}}*/

+class APT_HIDDEN CleanupItem : public pkgAcqTransactionItem            /*{{{*/
+/* This class ensures that a file which was configured but isn't downloaded
+   for various reasons isn't kept in an old version in the lists directory.
+   In a way its the reverse of NoActionItem as it helps with removing files
+   even if the lists-cleanup is deactivated. */
+{
+   public:
+   virtual std::string DescURI() const APT_OVERRIDE {return Target.URI;};
+   virtual HashStringList GetExpectedHashes()  const APT_OVERRIDE {return HashStringList();};
+
+   CleanupItem(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager, IndexTarget const &Target) :
+      pkgAcqTransactionItem(Owner, TransactionManager, Target)
+   {
+      Status = StatDone;
+      DestFile = GetFinalFileNameFromURI(Target.URI);
+   }
+   bool TransactionState(TransactionStates const state) APT_OVERRIDE
+   {
+      switch (state)
+      {
+        case TransactionStarted:
+           break;
+        case TransactionAbort:
+           break;
+        case TransactionCommit:
+           if (_config->FindB("Debug::Acquire::Transaction", false) == true)
+              std::clog << "rm " << DestFile << " # " << DescURI() << std::endl;
+           if (RemoveFile("TransItem::TransactionCommit", DestFile) == false)
+              return false;
+           break;
+      }
+      return true;
+   }
+};
+                                                                       /*}}}*/

 
 // Acquire::Item::Item - Constructor                                   /*{{{*/
 
 // Acquire::Item::Item - Constructor                                   /*{{{*/

+class pkgAcquire::Item::Private
+{
+public:
+   std::vector<std::string> PastRedirections;
+};

 APT_IGNORE_DEPRECATED_PUSH
 pkgAcquire::Item::Item(pkgAcquire * const owner) :
    FileSize(0), PartialSize(0), Mode(0), ID(0), Complete(false), Local(false),
 APT_IGNORE_DEPRECATED_PUSH
 pkgAcquire::Item::Item(pkgAcquire * const owner) :
    FileSize(0), PartialSize(0), Mode(0), ID(0), Complete(false), Local(false),

-    QueueCounter(0), ExpectedAdditionalItems(0), Owner(owner), d(NULL)
+    QueueCounter(0), ExpectedAdditionalItems(0), Owner(owner), d(new Private())

 {
    Owner->Add(this);
    Status = StatIdle;
 {
    Owner->Add(this);
    Status = StatIdle;


@@ -492,6 +712,7 @@ APT_IGNORE_DEPRECATED_POP
 pkgAcquire::Item::~Item()
 {
    Owner->Remove(this);
 pkgAcquire::Item::~Item()
 {
    Owner->Remove(this);

+   delete d;

 }
                                                                        /*}}}*/
 std::string pkgAcquire::Item::Custom600Headers() const                 /*{{{*/
 }
                                                                        /*}}}*/
 std::string pkgAcquire::Item::Custom600Headers() const                 /*{{{*/


@@ -527,10 +748,20 @@ APT_CONST bool pkgAcquire::Item::IsTrusted() const                        /*{{{*/
 // ---------------------------------------------------------------------
 /* We return to an idle state if there are still other queues that could
    fetch this object */
 // ---------------------------------------------------------------------
 /* We return to an idle state if there are still other queues that could
    fetch this object */

+static void formatHashsum(std::ostream &out, HashString const &hs)
+{
+   auto const type = hs.HashType();
+   if (type == "Checksum-FileSize")
+      out << " - Filesize";
+   else
+      out << " - " << type;
+   out << ':' << hs.HashValue();
+   if (hs.usable() == false)
+      out << " [weak]";
+   out << std::endl;
+}

 void pkgAcquire::Item::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf)
 {
 void pkgAcquire::Item::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf)
 {

-   if(ErrorText.empty())
-      ErrorText = LookupTag(Message,"Message");

    if (QueueCounter <= 1)
    {
       /* This indicates that the file is not available right now but might
    if (QueueCounter <= 1)
    {
       /* This indicates that the file is not available right now but might


@@ -561,16 +792,78 @@ void pkgAcquire::Item::Failed(string const &Message,pkgAcquire::MethodConfig con
    }
 
    string const FailReason = LookupTag(Message, "FailReason");
    }
 
    string const FailReason = LookupTag(Message, "FailReason");

-   if (FailReason == "MaximumSizeExceeded")
-      RenameOnError(MaximumSizeExceeded);
+   enum { MAXIMUM_SIZE_EXCEEDED, HASHSUM_MISMATCH, WEAK_HASHSUMS, REDIRECTION_LOOP, OTHER } failreason = OTHER;
+   if ( FailReason == "MaximumSizeExceeded")
+      failreason = MAXIMUM_SIZE_EXCEEDED;
+   else if ( FailReason == "WeakHashSums")
+      failreason = WEAK_HASHSUMS;
+   else if (FailReason == "RedirectionLoop")
+      failreason = REDIRECTION_LOOP;

    else if (Status == StatAuthError)
    else if (Status == StatAuthError)

-      RenameOnError(HashSumMismatch);
+      failreason = HASHSUM_MISMATCH;
+
+   if(ErrorText.empty())
+   {
+      std::ostringstream out;
+      switch (failreason)
+      {
+        case HASHSUM_MISMATCH:
+           out << _("Hash Sum mismatch") << std::endl;
+           break;
+        case WEAK_HASHSUMS:
+           out << _("Insufficient information available to perform this download securely") << std::endl;
+           break;
+        case REDIRECTION_LOOP:
+           out << "Redirection loop encountered" << std::endl;
+           break;
+        case MAXIMUM_SIZE_EXCEEDED:
+           out << LookupTag(Message, "Message") << std::endl;
+           break;
+        case OTHER:
+           out << LookupTag(Message, "Message");
+           break;
+      }
+
+      if (Status == StatAuthError)
+      {
+        auto const ExpectedHashes = GetExpectedHashes();
+        if (ExpectedHashes.empty() == false)
+        {
+           out << "Hashes of expected file:" << std::endl;
+           for (auto const &hs: ExpectedHashes)
+              formatHashsum(out, hs);
+        }
+        if (failreason == HASHSUM_MISMATCH)
+        {
+           out << "Hashes of received file:" << std::endl;
+           for (char const * const * type = HashString::SupportedHashes(); *type != NULL; ++type)
+           {
+              std::string const tagname = std::string(*type) + "-Hash";
+              std::string const hashsum = LookupTag(Message, tagname.c_str());
+              if (hashsum.empty() == false)
+                 formatHashsum(out, HashString(*type, hashsum));
+           }
+        }
+        auto const lastmod = LookupTag(Message, "Last-Modified", "");
+        if (lastmod.empty() == false)
+           out << "Last modification reported: " << lastmod << std::endl;
+      }
+      ErrorText = out.str();
+   }
+
+   switch (failreason)
+   {
+      case MAXIMUM_SIZE_EXCEEDED: RenameOnError(MaximumSizeExceeded); break;
+      case HASHSUM_MISMATCH: RenameOnError(HashSumMismatch); break;
+      case WEAK_HASHSUMS: break;
+      case REDIRECTION_LOOP: break;
+      case OTHER: break;
+   }

 
 

-   // report mirror failure back to LP if we actually use a mirror

    if (FailReason.empty() == false)
    if (FailReason.empty() == false)

-      ReportMirrorFailure(FailReason);
+      ReportMirrorFailureToCentral(*this, FailReason, ErrorText);

    else
    else

-      ReportMirrorFailure(ErrorText);
+      ReportMirrorFailureToCentral(*this, ErrorText, ErrorText);

 
    if (QueueCounter > 1)
       Status = StatIdle;
 
    if (QueueCounter > 1)
       Status = StatIdle;


@@ -658,13 +951,10 @@ bool pkgAcquire::Item::RenameOnError(pkgAcquire::Item::RenameOnErrorState const
    {
       case HashSumMismatch:
         errtext = _("Hash Sum mismatch");
    {
       case HashSumMismatch:
         errtext = _("Hash Sum mismatch");

-        Status = StatAuthError;
-        ReportMirrorFailure("HashChecksumFailure");

         break;
       case SizeMismatch:
         errtext = _("Size mismatch");
         Status = StatAuthError;
         break;
       case SizeMismatch:
         errtext = _("Size mismatch");
         Status = StatAuthError;

-        ReportMirrorFailure("SizeFailure");

         break;
       case InvalidFormat:
         errtext = _("Invalid file format");
         break;
       case InvalidFormat:
         errtext = _("Invalid file format");


@@ -681,7 +971,6 @@ bool pkgAcquire::Item::RenameOnError(pkgAcquire::Item::RenameOnErrorState const
         break;
       case MaximumSizeExceeded:
         // the method is expected to report a good error for this
         break;
       case MaximumSizeExceeded:
         // the method is expected to report a good error for this

-        Status = StatError;

         break;
       case PDiffError:
         // no handling here, done by callers
         break;
       case PDiffError:
         // no handling here, done by callers


@@ -699,47 +988,9 @@ void pkgAcquire::Item::SetActiveSubprocess(const std::string &subprocess)/*{{{*/
 }
                                                                        /*}}}*/
 // Acquire::Item::ReportMirrorFailure                                  /*{{{*/
 }
                                                                        /*}}}*/
 // Acquire::Item::ReportMirrorFailure                                  /*{{{*/

-void pkgAcquire::Item::ReportMirrorFailure(string const &FailCode)
+void pkgAcquire::Item::ReportMirrorFailure(std::string const &FailCode)

 {
 {

-   // we only act if a mirror was used at all
-   if(UsedMirror.empty())
-      return;
-#if 0
-   std::cerr << "\nReportMirrorFailure: " 
-            << UsedMirror
-            << " Uri: " << DescURI()
-            << " FailCode: " 
-            << FailCode << std::endl;
-#endif
-   string report = _config->Find("Methods::Mirror::ProblemReporting", 
-                                "/usr/lib/apt/apt-report-mirror-failure");
-   if(!FileExists(report))
-      return;
-
-   std::vector<char const*> Args;
-   Args.push_back(report.c_str());
-   Args.push_back(UsedMirror.c_str());
-   Args.push_back(DescURI().c_str());
-   Args.push_back(FailCode.c_str());
-   Args.push_back(NULL);
-
-   pid_t pid = ExecFork();
-   if(pid < 0)
-   {
-      _error->Error("ReportMirrorFailure Fork failed");
-      return;
-   }
-   else if(pid == 0)
-   {
-      execvp(Args[0], (char**)Args.data());
-      std::cerr << "Could not exec " << Args[0] << std::endl;
-      _exit(100);
-   }
-   if(!ExecWait(pid, "report-mirror-failure"))
-   {
-      _error->Warning("Couldn't report problem to '%s'",
-                     _config->Find("Methods::Mirror::ProblemReporting").c_str());
-   }
+   ReportMirrorFailureToCentral(*this, FailCode, FailCode);

 }
                                                                        /*}}}*/
 std::string pkgAcquire::Item::HashSum() const                          /*{{{*/
 }
                                                                        /*}}}*/
 std::string pkgAcquire::Item::HashSum() const                          /*{{{*/


@@ -749,6 +1000,47 @@ std::string pkgAcquire::Item::HashSum() const                             /*{{{*/
    return hs != NULL ? hs->toStr() : "";
 }
                                                                        /*}}}*/
    return hs != NULL ? hs->toStr() : "";
 }
                                                                        /*}}}*/

+bool pkgAcquire::Item::IsRedirectionLoop(std::string const &NewURI)    /*{{{*/
+{
+   // store can fail due to permission errors and the item will "loop" then
+   if (APT::String::Startswith(NewURI, "store:"))
+      return false;
+   if (d->PastRedirections.empty())
+   {
+      d->PastRedirections.push_back(NewURI);
+      return false;
+   }
+   auto const LastURI = std::prev(d->PastRedirections.end());
+   // redirections to the same file are a way of restarting/resheduling,
+   // individual methods will have to make sure that they aren't looping this way
+   if (*LastURI == NewURI)
+      return false;
+   if (std::find(d->PastRedirections.begin(), LastURI, NewURI) != LastURI)
+      return true;
+   d->PastRedirections.push_back(NewURI);
+   return false;
+}
+                                                                       /*}}}*/
+int pkgAcquire::Item::Priority()                                       /*{{{*/
+{
+   // Stage 1: Meta indices and diff indices
+   // - those need to be fetched first to have progress reporting working
+   //   for the rest
+   if (dynamic_cast<pkgAcqMetaSig*>(this) != nullptr
+       || dynamic_cast<pkgAcqMetaBase*>(this) != nullptr
+       || dynamic_cast<pkgAcqDiffIndex*>(this) != nullptr)
+      return 1000;
+   // Stage 2: Diff files
+   // - fetch before complete indexes so we can apply the diffs while fetching
+   //   larger files.
+   if (dynamic_cast<pkgAcqIndexDiffs*>(this) != nullptr ||
+       dynamic_cast<pkgAcqIndexMergeDiffs*>(this) != nullptr)
+      return 800;
+
+   // Stage 3: The rest - complete index files and other stuff
+   return 500;
+}
+                                                                       /*}}}*/

 
 pkgAcqTransactionItem::pkgAcqTransactionItem(pkgAcquire * const Owner, /*{{{*/
       pkgAcqMetaClearSig * const transactionManager, IndexTarget const &target) :
 
 pkgAcqTransactionItem::pkgAcqTransactionItem(pkgAcquire * const Owner, /*{{{*/
       pkgAcqMetaClearSig * const transactionManager, IndexTarget const &target) :


@@ -768,14 +1060,38 @@ HashStringList pkgAcqTransactionItem::GetExpectedHashesFor(std::string const &Me
 }
                                                                        /*}}}*/
 
 }
                                                                        /*}}}*/
 

+static void LoadLastMetaIndexParser(pkgAcqMetaClearSig * const TransactionManager, std::string const &FinalRelease, std::string const &FinalInRelease)/*{{{*/
+{
+   if (TransactionManager->IMSHit == true)
+      return;
+   if (RealFileExists(FinalInRelease) || RealFileExists(FinalRelease))
+   {
+      TransactionManager->LastMetaIndexParser = TransactionManager->MetaIndexParser->UnloadedClone();
+      if (TransactionManager->LastMetaIndexParser != NULL)
+      {
+        _error->PushToStack();
+        if (RealFileExists(FinalInRelease))
+           TransactionManager->LastMetaIndexParser->Load(FinalInRelease, NULL);
+        else
+           TransactionManager->LastMetaIndexParser->Load(FinalRelease, NULL);
+        // its unlikely to happen, but if what we have is bad ignore it
+        if (_error->PendingError())
+        {
+           delete TransactionManager->LastMetaIndexParser;
+           TransactionManager->LastMetaIndexParser = NULL;
+        }
+        _error->RevertToStack();
+      }
+   }
+}
+                                                                       /*}}}*/
+

 // AcqMetaBase - Constructor                                           /*{{{*/
 pkgAcqMetaBase::pkgAcqMetaBase(pkgAcquire * const Owner,
       pkgAcqMetaClearSig * const TransactionManager,
 // AcqMetaBase - Constructor                                           /*{{{*/
 pkgAcqMetaBase::pkgAcqMetaBase(pkgAcquire * const Owner,
       pkgAcqMetaClearSig * const TransactionManager,

-      std::vector<IndexTarget> const &IndexTargets,

       IndexTarget const &DataTarget)
 : pkgAcqTransactionItem(Owner, TransactionManager, DataTarget), d(NULL),
       IndexTarget const &DataTarget)
 : pkgAcqTransactionItem(Owner, TransactionManager, DataTarget), d(NULL),

-   IndexTargets(IndexTargets),
-   AuthPass(false), IMSHit(false)
+   AuthPass(false), IMSHit(false), State(TransactionStarted)

 {
 }
                                                                        /*}}}*/
 {
 }
                                                                        /*}}}*/


@@ -791,10 +1107,20 @@ void pkgAcqMetaBase::AbortTransaction()
    if(_config->FindB("Debug::Acquire::Transaction", false) == true)
       std::clog << "AbortTransaction: " << TransactionManager << std::endl;
 
    if(_config->FindB("Debug::Acquire::Transaction", false) == true)
       std::clog << "AbortTransaction: " << TransactionManager << std::endl;
 

+   switch (TransactionManager->State)
+   {
+      case TransactionStarted: break;
+      case TransactionAbort: _error->Fatal("Transaction %s was already aborted and is aborted again", TransactionManager->Target.URI.c_str()); return;
+      case TransactionCommit: _error->Fatal("Transaction %s was already aborted and is now committed", TransactionManager->Target.URI.c_str()); return;
+   }
+   TransactionManager->State = TransactionAbort;
+

    // ensure the toplevel is in error state too
    for (std::vector<pkgAcqTransactionItem*>::iterator I = Transaction.begin();
         I != Transaction.end(); ++I)
    {
    // ensure the toplevel is in error state too
    for (std::vector<pkgAcqTransactionItem*>::iterator I = Transaction.begin();
         I != Transaction.end(); ++I)
    {

+      if ((*I)->Status != pkgAcquire::Item::StatFetching)
+        Owner->Dequeue(*I);

       (*I)->TransactionState(TransactionAbort);
    }
    Transaction.clear();
       (*I)->TransactionState(TransactionAbort);
    }
    Transaction.clear();


@@ -824,6 +1150,14 @@ void pkgAcqMetaBase::CommitTransaction()
    if(_config->FindB("Debug::Acquire::Transaction", false) == true)
       std::clog << "CommitTransaction: " << this << std::endl;
 
    if(_config->FindB("Debug::Acquire::Transaction", false) == true)
       std::clog << "CommitTransaction: " << this << std::endl;
 

+   switch (TransactionManager->State)
+   {
+      case TransactionStarted: break;
+      case TransactionAbort: _error->Fatal("Transaction %s was already committed and is now aborted", TransactionManager->Target.URI.c_str()); return;
+      case TransactionCommit: _error->Fatal("Transaction %s was already committed and is again committed", TransactionManager->Target.URI.c_str()); return;
+   }
+   TransactionManager->State = TransactionCommit;
+

    // move new files into place *and* remove files that are not
    // part of the transaction but are still on disk
    for (std::vector<pkgAcqTransactionItem*>::iterator I = Transaction.begin();
    // move new files into place *and* remove files that are not
    // part of the transaction but are still on disk
    for (std::vector<pkgAcqTransactionItem*>::iterator I = Transaction.begin();


@@ -852,37 +1186,36 @@ void pkgAcqMetaBase::TransactionStageRemoval(pkgAcqTransactionItem * const I,
 }
                                                                        /*}}}*/
 // AcqMetaBase::GenerateAuthWarning - Check gpg authentication error   /*{{{*/
 }
                                                                        /*}}}*/
 // AcqMetaBase::GenerateAuthWarning - Check gpg authentication error   /*{{{*/

+/* This method is called from ::Failed handlers. If it returns true,
+   no fallback to other files or modi is performed */

 bool pkgAcqMetaBase::CheckStopAuthentication(pkgAcquire::Item * const I, const std::string &Message)
 {
 bool pkgAcqMetaBase::CheckStopAuthentication(pkgAcquire::Item * const I, const std::string &Message)
 {

-   // FIXME: this entire function can do now that we disallow going to
-   //        a unauthenticated state and can cleanly rollback
-

    string const Final = I->GetFinalFilename();
    string const Final = I->GetFinalFilename();

-   if(FileExists(Final))
+   std::string const GPGError = LookupTag(Message, "Message");
+   if (FileExists(Final))

    {
       I->Status = StatTransientNetworkError;
    {
       I->Status = StatTransientNetworkError;

-      _error->Warning(_("An error occurred during the signature "
-                        "verification. The repository is not updated "
-                        "and the previous index files will be used. "
-                        "GPG error: %s: %s"),
-                      Desc.Description.c_str(),
-                      LookupTag(Message,"Message").c_str());
+      _error->Warning(_("An error occurred during the signature verification. "
+              "The repository is not updated and the previous index files will be used. "
+              "GPG error: %s: %s"),
+           Desc.Description.c_str(),
+           GPGError.c_str());

       RunScripts("APT::Update::Auth-Failure");
       return true;
    } else if (LookupTag(Message,"Message").find("NODATA") != string::npos) {
       /* Invalid signature file, reject (LP: #346386) (Closes: #627642) */
       _error->Error(_("GPG error: %s: %s"),
       RunScripts("APT::Update::Auth-Failure");
       return true;
    } else if (LookupTag(Message,"Message").find("NODATA") != string::npos) {
       /* Invalid signature file, reject (LP: #346386) (Closes: #627642) */
       _error->Error(_("GPG error: %s: %s"),

-                    Desc.Description.c_str(),
-                    LookupTag(Message,"Message").c_str());
+           Desc.Description.c_str(),
+           GPGError.c_str());

       I->Status = StatAuthError;
       return true;
    } else {
       _error->Warning(_("GPG error: %s: %s"),
       I->Status = StatAuthError;
       return true;
    } else {
       _error->Warning(_("GPG error: %s: %s"),

-                      Desc.Description.c_str(),
-                      LookupTag(Message,"Message").c_str());
+           Desc.Description.c_str(),
+           GPGError.c_str());

    }
    // gpgv method failed
    }
    // gpgv method failed

-   ReportMirrorFailure("GPGFailure");
+   ReportMirrorFailureToCentral(*this, "GPGFailure", GPGError);

    return false;
 }
                                                                        /*}}}*/
    return false;
 }
                                                                        /*}}}*/


@@ -899,7 +1232,7 @@ string pkgAcqMetaBase::Custom600Headers() const
    string const FinalFile = GetFinalFilename();
    struct stat Buf;
    if (stat(FinalFile.c_str(),&Buf) == 0)
    string const FinalFile = GetFinalFilename();
    struct stat Buf;
    if (stat(FinalFile.c_str(),&Buf) == 0)

-      Header += "\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
+      Header += "\nLast-Modified: " + TimeRFC1123(Buf.st_mtime, false);

 
    return Header;
 }
 
    return Header;
 }


@@ -920,6 +1253,21 @@ bool pkgAcqMetaBase::CheckDownloadDone(pkgAcqTransactionItem * const I, const st
    // We have just finished downloading a Release file (it is not
    // verified yet)
 
    // We have just finished downloading a Release file (it is not
    // verified yet)
 

+   // Save the final base URI we got this Release file from
+   if (I->UsedMirror.empty() == false && _config->FindB("Acquire::SameMirrorForAllIndexes", true))
+   {
+      if (APT::String::Endswith(I->Desc.URI, "InRelease"))
+      {
+        TransactionManager->BaseURI = I->Desc.URI.substr(0, I->Desc.URI.length() - strlen("InRelease"));
+        TransactionManager->UsedMirror = I->UsedMirror;
+      }
+      else if (APT::String::Endswith(I->Desc.URI, "Release"))
+      {
+        TransactionManager->BaseURI = I->Desc.URI.substr(0, I->Desc.URI.length() - strlen("Release"));
+        TransactionManager->UsedMirror = I->UsedMirror;
+      }
+   }
+

    std::string const FileName = LookupTag(Message,"Filename");
    if (FileName != I->DestFile && RealFileExists(I->DestFile) == false)
    {
    std::string const FileName = LookupTag(Message,"Filename");
    if (FileName != I->DestFile && RealFileExists(I->DestFile) == false)
    {


@@ -946,8 +1294,7 @@ bool pkgAcqMetaBase::CheckDownloadDone(pkgAcqTransactionItem * const I, const st
    {
       // for simplicity, the transaction manager is always InRelease
       // even if it doesn't exist.
    {
       // for simplicity, the transaction manager is always InRelease
       // even if it doesn't exist.

-      if (TransactionManager != NULL)
-        TransactionManager->IMSHit = true;
+      TransactionManager->IMSHit = true;

       I->PartialFile = I->DestFile = I->GetFinalFilename();
    }
 
       I->PartialFile = I->DestFile = I->GetFinalFilename();
    }
 


@@ -963,6 +1310,8 @@ bool pkgAcqMetaBase::CheckAuthDone(string const &Message)          /*{{{*/
    // valid signature from a key in the trusted keyring.  We
    // perform additional verification of its contents, and use them
    // to verify the indexes we are about to download
    // valid signature from a key in the trusted keyring.  We
    // perform additional verification of its contents, and use them
    // to verify the indexes we are about to download

+   if (_config->FindB("Debug::pkgAcquire::Auth", false))
+      std::cerr << "Signature verification succeeded: " << DestFile << std::endl;

 
    if (TransactionManager->IMSHit == false)
    {
 
    if (TransactionManager->IMSHit == false)
    {


@@ -980,28 +1329,11 @@ bool pkgAcqMetaBase::CheckAuthDone(string const &Message)                /*{{{*/
         FinalInRelease = FinalFile.substr(0, FinalFile.length() - strlen("Release")) + "InRelease";
         FinalRelease = FinalFile;
       }
         FinalInRelease = FinalFile.substr(0, FinalFile.length() - strlen("Release")) + "InRelease";
         FinalRelease = FinalFile;
       }

-      if (RealFileExists(FinalInRelease) || RealFileExists(FinalRelease))
-      {
-        TransactionManager->LastMetaIndexParser = TransactionManager->MetaIndexParser->UnloadedClone();
-        if (TransactionManager->LastMetaIndexParser != NULL)
-        {
-           _error->PushToStack();
-           if (RealFileExists(FinalInRelease))
-              TransactionManager->LastMetaIndexParser->Load(FinalInRelease, NULL);
-           else
-              TransactionManager->LastMetaIndexParser->Load(FinalRelease, NULL);
-           // its unlikely to happen, but if what we have is bad ignore it
-           if (_error->PendingError())
-           {
-              delete TransactionManager->LastMetaIndexParser;
-              TransactionManager->LastMetaIndexParser = NULL;
-           }
-           _error->RevertToStack();
-        }
-      }
+      LoadLastMetaIndexParser(TransactionManager, FinalRelease, FinalInRelease);

    }
 
    }
 

-   if (TransactionManager->MetaIndexParser->Load(DestFile, &ErrorText) == false)
+   bool const GoodAuth = TransactionManager->MetaIndexParser->Load(DestFile, &ErrorText);
+   if (GoodAuth == false && AllowInsecureRepositories(InsecureType::WEAK, Target.Description, TransactionManager->MetaIndexParser, TransactionManager, this) == false)

    {
       Status = StatAuthError;
       return false;
    {
       Status = StatAuthError;
       return false;


@@ -1013,82 +1345,146 @@ bool pkgAcqMetaBase::CheckAuthDone(string const &Message)              /*{{{*/
       return false;
    }
 
       return false;
    }
 

-   if (_config->FindB("Debug::pkgAcquire::Auth", false))
-      std::cerr << "Signature verification succeeded: "
-                << DestFile << std::endl;
-

    // Download further indexes with verification
    // Download further indexes with verification

-   QueueIndexes(true);
+   TransactionManager->QueueIndexes(GoodAuth);

 
 

-   return true;
+   return GoodAuth;

 }
                                                                        /*}}}*/
 }
                                                                        /*}}}*/

-void pkgAcqMetaBase::QueueIndexes(bool const verify)                   /*{{{*/
+void pkgAcqMetaClearSig::QueueIndexes(bool const verify)                       /*{{{*/

 {
    // at this point the real Items are loaded in the fetcher
    ExpectedAdditionalItems = 0;
 
 {
    // at this point the real Items are loaded in the fetcher
    ExpectedAdditionalItems = 0;
 

-  bool metaBaseSupportsByHash = false;
-  if (TransactionManager != NULL && TransactionManager->MetaIndexParser != NULL)
-     metaBaseSupportsByHash = TransactionManager->MetaIndexParser->GetSupportsAcquireByHash();
-
-   for (std::vector <IndexTarget>::iterator Target = IndexTargets.begin();
-        Target != IndexTargets.end();
-        ++Target)
-   {
+   std::set<std::string> targetsSeen;
+   bool const hasReleaseFile = TransactionManager->MetaIndexParser != NULL;
+   bool const metaBaseSupportsByHash = hasReleaseFile && TransactionManager->MetaIndexParser->GetSupportsAcquireByHash();
+   bool hasHashes = true;
+   auto IndexTargets = TransactionManager->MetaIndexParser->GetIndexTargets();
+   if (hasReleaseFile && verify == false)
+      hasHashes = std::any_of(IndexTargets.begin(), IndexTargets.end(),
+           [&](IndexTarget const &Target) { return TransactionManager->MetaIndexParser->Exists(Target.MetaKey); });
+   if (_config->FindB("Acquire::IndexTargets::Randomized", true) && likely(IndexTargets.empty() == false))
+   {
+      /* For fallback handling and to have some reasonable progress information
+        we can't randomize everything, but at least the order in the same type
+        can be as we shouldn't be telling the mirrors (and everyone else watching)
+        which is native/foreign arch, specific order of preference of translations, … */
+      auto range_start = IndexTargets.begin();
+      std::random_device rd;
+      std::default_random_engine g(rd());
+      do {
+        auto const type = range_start->Option(IndexTarget::CREATED_BY);
+        auto const range_end = std::find_if_not(range_start, IndexTargets.end(),
+              [&type](IndexTarget const &T) { return type == T.Option(IndexTarget::CREATED_BY); });
+        std::shuffle(range_start, range_end, g);
+        range_start = range_end;
+      } while (range_start != IndexTargets.end());
+   }
+   for (auto&& Target: IndexTargets)
+   {
+      // if we have seen a target which is created-by a target this one here is declared a
+      // fallback to, we skip acquiring the fallback (but we make sure we clean up)
+      if (targetsSeen.find(Target.Option(IndexTarget::FALLBACK_OF)) != targetsSeen.end())
+      {
+        targetsSeen.emplace(Target.Option(IndexTarget::CREATED_BY));
+        new CleanupItem(Owner, TransactionManager, Target);
+        continue;
+      }

       // all is an implementation detail. Users shouldn't use this as arch
       // We need this support trickery here as e.g. Debian has binary-all files already,
       // but arch:all packages are still in the arch:any files, so we would waste precious
       // download time, bandwidth and diskspace for nothing, BUT Debian doesn't feature all
       // in the set of supported architectures, so we can filter based on this property rather
       // than invent an entirely new flag we would need to carry for all of eternity.
       // all is an implementation detail. Users shouldn't use this as arch
       // We need this support trickery here as e.g. Debian has binary-all files already,
       // but arch:all packages are still in the arch:any files, so we would waste precious
       // download time, bandwidth and diskspace for nothing, BUT Debian doesn't feature all
       // in the set of supported architectures, so we can filter based on this property rather
       // than invent an entirely new flag we would need to carry for all of eternity.

-      if (Target->Option(IndexTarget::ARCHITECTURE) == "all" &&
-           TransactionManager->MetaIndexParser->IsArchitectureSupported("all") == false)
-        continue;
+      if (hasReleaseFile && Target.Option(IndexTarget::ARCHITECTURE) == "all")
+      {
+        if (TransactionManager->MetaIndexParser->IsArchitectureAllSupportedFor(Target) == false)
+        {
+           new CleanupItem(Owner, TransactionManager, Target);
+           continue;
+        }
+      }

 
 

-      bool trypdiff = Target->OptionBool(IndexTarget::PDIFFS);
-      if (verify == true)
+      bool trypdiff = Target.OptionBool(IndexTarget::PDIFFS);
+      if (hasReleaseFile == true)

       {
       {

-        if (TransactionManager->MetaIndexParser->Exists(Target->MetaKey) == false)
+        if (TransactionManager->MetaIndexParser->Exists(Target.MetaKey) == false)

         {
            // optional targets that we do not have in the Release file are skipped
         {
            // optional targets that we do not have in the Release file are skipped

-           if (Target->IsOptional)
+           if (hasHashes == true && Target.IsOptional)
+           {
+              new CleanupItem(Owner, TransactionManager, Target);

               continue;
               continue;

+           }

 
 

-           std::string const &arch = Target->Option(IndexTarget::ARCHITECTURE);
+           std::string const &arch = Target.Option(IndexTarget::ARCHITECTURE);

            if (arch.empty() == false)
            {
               if (TransactionManager->MetaIndexParser->IsArchitectureSupported(arch) == false)
               {
            if (arch.empty() == false)
            {
               if (TransactionManager->MetaIndexParser->IsArchitectureSupported(arch) == false)
               {

+                 new CleanupItem(Owner, TransactionManager, Target);

                  _error->Notice(_("Skipping acquire of configured file '%s' as repository '%s' doesn't support architecture '%s'"),
                  _error->Notice(_("Skipping acquire of configured file '%s' as repository '%s' doesn't support architecture '%s'"),

-                       Target->MetaKey.c_str(), TransactionManager->Target.Description.c_str(), arch.c_str());
+                       Target.MetaKey.c_str(), TransactionManager->Target.Description.c_str(), arch.c_str());

                  continue;
               }
               // if the architecture is officially supported but currently no packages for it available,
               // ignore silently as this is pretty much the same as just shipping an empty file.
               // if we don't know which architectures are supported, we do NOT ignore it to notify user about this
                  continue;
               }
               // if the architecture is officially supported but currently no packages for it available,
               // ignore silently as this is pretty much the same as just shipping an empty file.
               // if we don't know which architectures are supported, we do NOT ignore it to notify user about this

-              if (TransactionManager->MetaIndexParser->IsArchitectureSupported("*undefined*") == false)
+              if (hasHashes == true && TransactionManager->MetaIndexParser->IsArchitectureSupported("*undefined*") == false)
+              {
+                 new CleanupItem(Owner, TransactionManager, Target);

                  continue;
                  continue;

+              }

            }
 
            }
 

-           Status = StatAuthError;
-           strprintf(ErrorText, _("Unable to find expected entry '%s' in Release file (Wrong sources.list entry or malformed file)"), Target->MetaKey.c_str());
-           return;
+           if (hasHashes == true)
+           {
+              Status = StatAuthError;
+              strprintf(ErrorText, _("Unable to find expected entry '%s' in Release file (Wrong sources.list entry or malformed file)"), Target.MetaKey.c_str());
+              return;
+           }
+           else
+           {
+              new pkgAcqIndex(Owner, TransactionManager, Target);
+              continue;
+           }
+        }
+        else if (verify)
+        {
+           auto const hashes = GetExpectedHashesFor(Target.MetaKey);
+           if (hashes.empty() == false)
+           {
+              if (hashes.usable() == false && TargetIsAllowedToBe(TransactionManager->Target, InsecureType::WEAK) == false)
+              {
+                 new CleanupItem(Owner, TransactionManager, Target);
+                 _error->Warning(_("Skipping acquire of configured file '%s' as repository '%s' provides only weak security information for it"),
+                       Target.MetaKey.c_str(), TransactionManager->Target.Description.c_str());
+                 continue;
+              }
+              // empty files are skipped as acquiring the very small compressed files is a waste of time
+              else if (hashes.FileSize() == 0)
+              {
+                 new CleanupItem(Owner, TransactionManager, Target);
+                 targetsSeen.emplace(Target.Option(IndexTarget::CREATED_BY));
+                 continue;
+              }
+           }

         }
 
         // autoselect the compression method
         }
 
         // autoselect the compression method

-        std::vector<std::string> types = VectorizeString(Target->Option(IndexTarget::COMPRESSIONTYPES), ' ');
+        std::vector<std::string> types = VectorizeString(Target.Option(IndexTarget::COMPRESSIONTYPES), ' ');

         types.erase(std::remove_if(types.begin(), types.end(), [&](std::string const &t) {
            if (t == "uncompressed")
         types.erase(std::remove_if(types.begin(), types.end(), [&](std::string const &t) {
            if (t == "uncompressed")

-              return TransactionManager->MetaIndexParser->Exists(Target->MetaKey) == false;
-           std::string const MetaKey = Target->MetaKey + "." + t;
+              return TransactionManager->MetaIndexParser->Exists(Target.MetaKey) == false;
+           std::string const MetaKey = Target.MetaKey + "." + t;

            return TransactionManager->MetaIndexParser->Exists(MetaKey) == false;
         }), types.end());
         if (types.empty() == false)
         {
            std::ostringstream os;
            // add the special compressiontype byhash first if supported
            return TransactionManager->MetaIndexParser->Exists(MetaKey) == false;
         }), types.end());
         if (types.empty() == false)
         {
            std::ostringstream os;
            // add the special compressiontype byhash first if supported

-           std::string const useByHashConf = Target->Option(IndexTarget::BY_HASH);
+           std::string const useByHashConf = Target.Option(IndexTarget::BY_HASH);

            bool useByHash = false;
            if(useByHashConf == "force")
               useByHash = true;
            bool useByHash = false;
            if(useByHashConf == "force")
               useByHash = true;


@@ -1098,24 +1494,12 @@ void pkgAcqMetaBase::QueueIndexes(bool const verify)                    /*{{{*/
               os << "by-hash ";
            std::copy(types.begin(), types.end()-1, std::ostream_iterator<std::string>(os, " "));
            os << *types.rbegin();
               os << "by-hash ";
            std::copy(types.begin(), types.end()-1, std::ostream_iterator<std::string>(os, " "));
            os << *types.rbegin();

-           Target->Options["COMPRESSIONTYPES"] = os.str();
+           Target.Options["COMPRESSIONTYPES"] = os.str();

         }
         else
         }
         else

-           Target->Options["COMPRESSIONTYPES"].clear();
-
-        std::string filename = GetFinalFileNameFromURI(Target->URI);
-        if (RealFileExists(filename) == false)
-        {
-           if (Target->KeepCompressed)
-           {
-              filename = GetKeepCompressedFileName(filename, *Target);
-              if (RealFileExists(filename) == false)
-                 filename.clear();
-           }
-           else
-              filename.clear();
-        }
+           Target.Options["COMPRESSIONTYPES"].clear();

 
 

+        std::string filename = GetExistingFilename(GetFinalFileNameFromURI(Target.URI));

         if (filename.empty() == false)
         {
            // if the Release file is a hit and we have an index it must be the current one
         if (filename.empty() == false)
         {
            // if the Release file is a hit and we have an index it must be the current one


@@ -1126,8 +1510,8 @@ void pkgAcqMetaBase::QueueIndexes(bool const verify)                      /*{{{*/
               // see if the file changed since the last Release file
               // we use the uncompressed files as we might compress differently compared to the server,
               // so the hashes might not match, even if they contain the same data.
               // see if the file changed since the last Release file
               // we use the uncompressed files as we might compress differently compared to the server,
               // so the hashes might not match, even if they contain the same data.

-              HashStringList const newFile = GetExpectedHashesFromFor(TransactionManager->MetaIndexParser, Target->MetaKey);
-              HashStringList const oldFile = GetExpectedHashesFromFor(TransactionManager->LastMetaIndexParser, Target->MetaKey);
+              HashStringList const newFile = GetExpectedHashesFromFor(TransactionManager->MetaIndexParser, Target.MetaKey);
+              HashStringList const oldFile = GetExpectedHashesFromFor(TransactionManager->LastMetaIndexParser, Target.MetaKey);

               if (newFile != oldFile)
                  filename.clear();
            }
               if (newFile != oldFile)
                  filename.clear();
            }


@@ -1139,87 +1523,42 @@ void pkgAcqMetaBase::QueueIndexes(bool const verify)                    /*{{{*/
 
         if (filename.empty() == false)
         {
 
         if (filename.empty() == false)
         {

-           new NoActionItem(Owner, *Target, filename);
-           std::string const idxfilename = GetFinalFileNameFromURI(Target->URI + ".diff/Index");
+           new NoActionItem(Owner, Target, filename);
+           std::string const idxfilename = GetFinalFileNameFromURI(GetDiffIndexURI(Target));

            if (FileExists(idxfilename))
            if (FileExists(idxfilename))

-              new NoActionItem(Owner, *Target, idxfilename);
+              new NoActionItem(Owner, Target, idxfilename);
+           targetsSeen.emplace(Target.Option(IndexTarget::CREATED_BY));

            continue;
         }
 
         // check if we have patches available
            continue;
         }
 
         // check if we have patches available

-        trypdiff &= TransactionManager->MetaIndexParser->Exists(Target->MetaKey + ".diff/Index");
+        trypdiff &= TransactionManager->MetaIndexParser->Exists(GetDiffIndexFileName(Target.MetaKey));

       }
       else
       {
         // if we have no file to patch, no point in trying
       }
       else
       {
         // if we have no file to patch, no point in trying

-        std::string filename = GetFinalFileNameFromURI(Target->URI);
-        if (RealFileExists(filename) == false)
-        {
-           if (Target->KeepCompressed)
-           {
-              filename = GetKeepCompressedFileName(filename, *Target);
-              if (RealFileExists(filename) == false)
-                 filename.clear();
-           }
-           else
-              filename.clear();
-        }
-        trypdiff &= (filename.empty() == false);
+        trypdiff &= (GetExistingFilename(GetFinalFileNameFromURI(Target.URI)).empty() == false);

       }
 
       // no point in patching from local sources
       if (trypdiff)
       {
       }
 
       // no point in patching from local sources
       if (trypdiff)
       {

-        std::string const proto = Target->URI.substr(0, strlen("file:/"));
+        std::string const proto = Target.URI.substr(0, strlen("file:/"));

         if (proto == "file:/" || proto == "copy:/" || proto == "cdrom:")
            trypdiff = false;
       }
 
       // Queue the Index file (Packages, Sources, Translation-$foo, …)
         if (proto == "file:/" || proto == "copy:/" || proto == "cdrom:")
            trypdiff = false;
       }
 
       // Queue the Index file (Packages, Sources, Translation-$foo, …)

+      targetsSeen.emplace(Target.Option(IndexTarget::CREATED_BY));

       if (trypdiff)
       if (trypdiff)

-         new pkgAcqDiffIndex(Owner, TransactionManager, *Target);
+         new pkgAcqDiffIndex(Owner, TransactionManager, Target);

       else
       else

-         new pkgAcqIndex(Owner, TransactionManager, *Target);
+         new pkgAcqIndex(Owner, TransactionManager, Target);

    }
 }
                                                                        /*}}}*/
    }
 }
                                                                        /*}}}*/

-bool pkgAcqMetaBase::VerifyVendor(string const &Message)               /*{{{*/
+bool pkgAcqMetaBase::VerifyVendor(string const &)                      /*{{{*/

 {
 {

-   string::size_type pos;
-
-   // check for missing sigs (that where not fatal because otherwise we had
-   // bombed earlier)
-   string missingkeys;
-   string msg = _("There is no public key available for the "
-                 "following key IDs:\n");
-   pos = Message.find("NO_PUBKEY ");
-   if (pos != std::string::npos)
-   {
-      string::size_type start = pos+strlen("NO_PUBKEY ");
-      string Fingerprint = Message.substr(start, Message.find("\n")-start);
-      missingkeys += (Fingerprint);
-   }
-   if(!missingkeys.empty())
-      _error->Warning("%s", (msg + missingkeys).c_str());
-
-   string Transformed = TransactionManager->MetaIndexParser->GetExpectedDist();
-
-   if (Transformed == "../project/experimental")
-   {
-      Transformed = "experimental";
-   }
-
-   pos = Transformed.rfind('/');
-   if (pos != string::npos)
-   {
-      Transformed = Transformed.substr(0, pos);
-   }
-
-   if (Transformed == ".")
-   {
-      Transformed = "";
-   }
-

    if (TransactionManager->MetaIndexParser->GetValidUntil() > 0)
    {
       time_t const invalid_since = time(NULL) - TransactionManager->MetaIndexParser->GetValidUntil();
    if (TransactionManager->MetaIndexParser->GetValidUntil() > 0)
    {
       time_t const invalid_since = time(NULL) - TransactionManager->MetaIndexParser->GetValidUntil();


@@ -1254,30 +1593,27 @@ bool pkgAcqMetaBase::VerifyVendor(string const &Message)                /*{{{*/
       TransactionManager->LastMetaIndexParser = NULL;
    }
 
       TransactionManager->LastMetaIndexParser = NULL;
    }
 

-   if (_config->FindB("Debug::pkgAcquire::Auth", false)) 
+   if (_config->FindB("Debug::pkgAcquire::Auth", false))

    {
       std::cerr << "Got Codename: " << TransactionManager->MetaIndexParser->GetCodename() << std::endl;
    {
       std::cerr << "Got Codename: " << TransactionManager->MetaIndexParser->GetCodename() << std::endl;

+      std::cerr << "Got Suite: " << TransactionManager->MetaIndexParser->GetSuite() << std::endl;

       std::cerr << "Expecting Dist: " << TransactionManager->MetaIndexParser->GetExpectedDist() << std::endl;
       std::cerr << "Expecting Dist: " << TransactionManager->MetaIndexParser->GetExpectedDist() << std::endl;

-      std::cerr << "Transformed Dist: " << Transformed << std::endl;

    }
 
    }
 

-   if (TransactionManager->MetaIndexParser->CheckDist(Transformed) == false)
+   // One day that might become fatal…
+   auto const ExpectedDist = TransactionManager->MetaIndexParser->GetExpectedDist();
+   auto const NowCodename = TransactionManager->MetaIndexParser->GetCodename();
+   if (TransactionManager->MetaIndexParser->CheckDist(ExpectedDist) == false)
+      _error->Warning(_("Conflicting distribution: %s (expected %s but got %s)"),
+           Desc.Description.c_str(), ExpectedDist.c_str(), NowCodename.c_str());
+   // might be okay, might be not
+   if (TransactionManager->LastMetaIndexParser != nullptr)

    {
    {

-      // This might become fatal one day
-//       Status = StatAuthError;
-//       ErrorText = "Conflicting distribution; expected "
-//          + MetaIndexParser->GetExpectedDist() + " but got "
-//          + MetaIndexParser->GetCodename();
-//       return false;
-      if (!Transformed.empty())
-      {
-         _error->Warning(_("Conflicting distribution: %s (expected %s but got %s)"),
-                         Desc.Description.c_str(),
-                         Transformed.c_str(),
-                         TransactionManager->MetaIndexParser->GetCodename().c_str());
-      }
+      auto const LastCodename = TransactionManager->LastMetaIndexParser->GetCodename();
+      if (LastCodename.empty() == false && NowCodename.empty() == false && LastCodename != NowCodename)
+        _error->Warning(_("Conflicting distribution: %s (expected %s but got %s)"),
+              Desc.Description.c_str(), LastCodename.c_str(), NowCodename.c_str());

    }
    }

-

    return true;
 }
                                                                        /*}}}*/
    return true;
 }
                                                                        /*}}}*/


@@ -1288,15 +1624,13 @@ pkgAcqMetaBase::~pkgAcqMetaBase()
 pkgAcqMetaClearSig::pkgAcqMetaClearSig(pkgAcquire * const Owner,       /*{{{*/
       IndexTarget const &ClearsignedTarget,
       IndexTarget const &DetachedDataTarget, IndexTarget const &DetachedSigTarget,
 pkgAcqMetaClearSig::pkgAcqMetaClearSig(pkgAcquire * const Owner,       /*{{{*/
       IndexTarget const &ClearsignedTarget,
       IndexTarget const &DetachedDataTarget, IndexTarget const &DetachedSigTarget,

-      std::vector<IndexTarget> const &IndexTargets,

       metaIndex * const MetaIndexParser) :
       metaIndex * const MetaIndexParser) :

-   pkgAcqMetaIndex(Owner, this, ClearsignedTarget, DetachedSigTarget, IndexTargets),
-   d(NULL), ClearsignedTarget(ClearsignedTarget),
-   DetachedDataTarget(DetachedDataTarget),
+   pkgAcqMetaIndex(Owner, this, ClearsignedTarget, DetachedSigTarget),
+   d(NULL), DetachedDataTarget(DetachedDataTarget),

    MetaIndexParser(MetaIndexParser), LastMetaIndexParser(NULL)
 {
    // index targets + (worst case:) Release/Release.gpg
    MetaIndexParser(MetaIndexParser), LastMetaIndexParser(NULL)
 {
    // index targets + (worst case:) Release/Release.gpg

-   ExpectedAdditionalItems = IndexTargets.size() + 2;
+   ExpectedAdditionalItems = std::numeric_limits<decltype(ExpectedAdditionalItems)>::max();

    TransactionManager->Add(this);
 }
                                                                        /*}}}*/
    TransactionManager->Add(this);
 }
                                                                        /*}}}*/


@@ -1318,6 +1652,15 @@ string pkgAcqMetaClearSig::Custom600Headers() const
    return Header;
 }
                                                                        /*}}}*/
    return Header;
 }
                                                                        /*}}}*/

+void pkgAcqMetaClearSig::Finished()                                    /*{{{*/
+{
+   if(_config->FindB("Debug::Acquire::Transaction", false) == true)
+      std::clog << "Finished: " << DestFile <<std::endl;
+   if(TransactionManager->State == TransactionStarted &&
+      TransactionManager->TransactionHasError() == false)
+      TransactionManager->CommitTransaction();
+}
+                                                                       /*}}}*/

 bool pkgAcqMetaClearSig::VerifyDone(std::string const &Message,                /*{{{*/
         pkgAcquire::MethodConfig const * const Cnf)
 {
 bool pkgAcqMetaClearSig::VerifyDone(std::string const &Message,                /*{{{*/
         pkgAcquire::MethodConfig const * const Cnf)
 {


@@ -1355,15 +1698,23 @@ void pkgAcqMetaClearSig::Done(std::string const &Message,
         new NoActionItem(Owner, DetachedSigTarget);
       }
    }
         new NoActionItem(Owner, DetachedSigTarget);
       }
    }

+   else if (Status != StatAuthError)
+   {
+      string const FinalFile = GetFinalFileNameFromURI(DetachedDataTarget.URI);
+      string const OldFile = GetFinalFilename();
+      if (TransactionManager->IMSHit == false)
+        TransactionManager->TransactionStageCopy(this, DestFile, FinalFile);
+      else if (RealFileExists(OldFile) == false)
+        new NoActionItem(Owner, DetachedDataTarget);
+      else
+        TransactionManager->TransactionStageCopy(this, OldFile, FinalFile);
+   }

 }
                                                                        /*}}}*/
 void pkgAcqMetaClearSig::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf) /*{{{*/
 {
    Item::Failed(Message, Cnf);
 
 }
                                                                        /*}}}*/
 void pkgAcqMetaClearSig::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf) /*{{{*/
 {
    Item::Failed(Message, Cnf);
 

-   // we failed, we will not get additional items from this method
-   ExpectedAdditionalItems = 0;
-

    if (AuthPass == false)
    {
       if (Status == StatAuthError || Status == StatTransientNetworkError)
    if (AuthPass == false)
    {
       if (Status == StatAuthError || Status == StatTransientNetworkError)


@@ -1382,17 +1733,14 @@ void pkgAcqMetaClearSig::Failed(string const &Message,pkgAcquire::MethodConfig c
       TransactionManager->TransactionStageRemoval(this, GetFinalFilename());
       Status = StatDone;
 
       TransactionManager->TransactionStageRemoval(this, GetFinalFilename());
       Status = StatDone;
 

-      new pkgAcqMetaIndex(Owner, TransactionManager, DetachedDataTarget, DetachedSigTarget, IndexTargets);
+      new pkgAcqMetaIndex(Owner, TransactionManager, DetachedDataTarget, DetachedSigTarget);

    }
    else
    {
       if(CheckStopAuthentication(this, Message))
          return;
 
    }
    else
    {
       if(CheckStopAuthentication(this, Message))
          return;
 

-      // No Release file was present, or verification failed, so fall
-      // back to queueing Packages files without verification
-      // only allow going further if the users explicitely wants it
-      if(AllowInsecureRepositories(_("The repository '%s' is not signed."), ClearsignedTarget.Description, TransactionManager->MetaIndexParser, TransactionManager, this) == true)
+      if(AllowInsecureRepositories(InsecureType::UNSIGNED, Target.Description, TransactionManager->MetaIndexParser, TransactionManager, this) == true)

       {
         Status = StatDone;
 
       {
         Status = StatDone;
 


@@ -1404,37 +1752,14 @@ void pkgAcqMetaClearSig::Failed(string const &Message,pkgAcquire::MethodConfig c
         string const FinalInRelease = GetFinalFilename();
         Rename(DestFile, PartialRelease);
         TransactionManager->TransactionStageCopy(this, PartialRelease, FinalRelease);
         string const FinalInRelease = GetFinalFilename();
         Rename(DestFile, PartialRelease);
         TransactionManager->TransactionStageCopy(this, PartialRelease, FinalRelease);

-
-        if (RealFileExists(FinalReleasegpg) || RealFileExists(FinalInRelease))
-        {
-           // open the last Release if we have it
-           if (TransactionManager->IMSHit == false)
-           {
-              TransactionManager->LastMetaIndexParser = TransactionManager->MetaIndexParser->UnloadedClone();
-              if (TransactionManager->LastMetaIndexParser != NULL)
-              {
-                 _error->PushToStack();
-                 if (RealFileExists(FinalInRelease))
-                    TransactionManager->LastMetaIndexParser->Load(FinalInRelease, NULL);
-                 else
-                    TransactionManager->LastMetaIndexParser->Load(FinalRelease, NULL);
-                 // its unlikely to happen, but if what we have is bad ignore it
-                 if (_error->PendingError())
-                 {
-                    delete TransactionManager->LastMetaIndexParser;
-                    TransactionManager->LastMetaIndexParser = NULL;
-                 }
-                 _error->RevertToStack();
-              }
-           }
-        }
+        LoadLastMetaIndexParser(TransactionManager, FinalRelease, FinalInRelease);

 
         // we parse the indexes here because at this point the user wanted
         // a repository that may potentially harm him
         if (TransactionManager->MetaIndexParser->Load(PartialRelease, &ErrorText) == false || VerifyVendor(Message) == false)
            /* expired Release files are still a problem you need extra force for */;
         else
 
         // we parse the indexes here because at this point the user wanted
         // a repository that may potentially harm him
         if (TransactionManager->MetaIndexParser->Load(PartialRelease, &ErrorText) == false || VerifyVendor(Message) == false)
            /* expired Release files are still a problem you need extra force for */;
         else

-           QueueIndexes(true);
+           TransactionManager->QueueIndexes(true);

       }
    }
 }
       }
    }
 }


@@ -1443,9 +1768,8 @@ void pkgAcqMetaClearSig::Failed(string const &Message,pkgAcquire::MethodConfig c
 pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire * const Owner,             /*{{{*/
                                  pkgAcqMetaClearSig * const TransactionManager,
                                 IndexTarget const &DataTarget,
 pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire * const Owner,             /*{{{*/
                                  pkgAcqMetaClearSig * const TransactionManager,
                                 IndexTarget const &DataTarget,

-                                IndexTarget const &DetachedSigTarget,
-                                vector<IndexTarget> const &IndexTargets) :
-   pkgAcqMetaBase(Owner, TransactionManager, IndexTargets, DataTarget), d(NULL),
+                                IndexTarget const &DetachedSigTarget) :
+   pkgAcqMetaBase(Owner, TransactionManager, DataTarget), d(NULL),

    DetachedSigTarget(DetachedSigTarget)
 {
    if(_config->FindB("Debug::Acquire::Transaction", false) == true)
    DetachedSigTarget(DetachedSigTarget)
 {
    if(_config->FindB("Debug::Acquire::Transaction", false) == true)


@@ -1459,9 +1783,6 @@ pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire * const Owner,                /*{{{*/
    Desc.Owner = this;
    Desc.ShortDesc = DataTarget.ShortDesc;
    Desc.URI = DataTarget.URI;
    Desc.Owner = this;
    Desc.ShortDesc = DataTarget.ShortDesc;
    Desc.URI = DataTarget.URI;

-
-   // we expect more item
-   ExpectedAdditionalItems = IndexTargets.size();

    QueueURI(Desc);
 }
                                                                        /*}}}*/
    QueueURI(Desc);
 }
                                                                        /*}}}*/


@@ -1489,26 +1810,17 @@ void pkgAcqMetaIndex::Failed(string const &Message,
 
    // No Release file was present so fall
    // back to queueing Packages files without verification
 
    // No Release file was present so fall
    // back to queueing Packages files without verification

-   // only allow going further if the users explicitely wants it
-   if(AllowInsecureRepositories(_("The repository '%s' does not have a Release file."), Target.Description, TransactionManager->MetaIndexParser, TransactionManager, this) == true)
+   // only allow going further if the user explicitly wants it
+   if(AllowInsecureRepositories(InsecureType::NORELEASE, Target.Description, TransactionManager->MetaIndexParser, TransactionManager, this) == true)

    {
       // ensure old Release files are removed
       TransactionManager->TransactionStageRemoval(this, GetFinalFilename());
 
       // queue without any kind of hashsum support
    {
       // ensure old Release files are removed
       TransactionManager->TransactionStageRemoval(this, GetFinalFilename());
 
       // queue without any kind of hashsum support

-      QueueIndexes(false);
+      TransactionManager->QueueIndexes(false);

    }
 }
                                                                        /*}}}*/
    }
 }
                                                                        /*}}}*/

-void pkgAcqMetaIndex::Finished()                                       /*{{{*/
-{
-   if(_config->FindB("Debug::Acquire::Transaction", false) == true)
-      std::clog << "Finished: " << DestFile <<std::endl;
-   if(TransactionManager != NULL &&
-      TransactionManager->TransactionHasError() == false)
-      TransactionManager->CommitTransaction();
-}
-                                                                       /*}}}*/

 std::string pkgAcqMetaIndex::DescURI() const                           /*{{{*/
 {
    return Target.URI;
 std::string pkgAcqMetaIndex::DescURI() const                           /*{{{*/
 {
    return Target.URI;


@@ -1593,12 +1905,26 @@ void pkgAcqMetaSig::Done(string const &Message, HashStringList const &Hashes,
    }
    else if(MetaIndex->CheckAuthDone(Message) == true)
    {
    }
    else if(MetaIndex->CheckAuthDone(Message) == true)
    {

-      if (TransactionManager->IMSHit == false)
+      auto const Releasegpg = GetFinalFilename();
+      auto const Release = MetaIndex->GetFinalFilename();
+      // if this is an IMS-Hit on Release ensure we also have the the Release.gpg file stored
+      // (previously an unknown pubkey) – but only if the Release file exists locally (unlikely
+      // event of InRelease removed from the mirror causing fallback but still an IMS-Hit)
+      if (TransactionManager->IMSHit == false ||
+           (FileExists(Releasegpg) == false && FileExists(Release) == true))

       {
       {

-        TransactionManager->TransactionStageCopy(this, DestFile, GetFinalFilename());
-        TransactionManager->TransactionStageCopy(MetaIndex, MetaIndex->DestFile, MetaIndex->GetFinalFilename());
+        TransactionManager->TransactionStageCopy(this, DestFile, Releasegpg);
+        TransactionManager->TransactionStageCopy(MetaIndex, MetaIndex->DestFile, Release);

       }
    }
       }
    }

+   else if (MetaIndex->Status != StatAuthError)
+   {
+      std::string const FinalFile = MetaIndex->GetFinalFilename();
+      if (TransactionManager->IMSHit == false)
+        TransactionManager->TransactionStageCopy(MetaIndex, MetaIndex->DestFile, FinalFile);
+      else
+        TransactionManager->TransactionStageCopy(MetaIndex, FinalFile, FinalFile);
+   }

 }
                                                                        /*}}}*/
 void pkgAcqMetaSig::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf)/*{{{*/
 }
                                                                        /*}}}*/
 void pkgAcqMetaSig::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf)/*{{{*/


@@ -1609,73 +1935,28 @@ void pkgAcqMetaSig::Failed(string const &Message,pkgAcquire::MethodConfig const
    if (MetaIndex->AuthPass == true && MetaIndex->CheckStopAuthentication(this, Message))
          return;
 
    if (MetaIndex->AuthPass == true && MetaIndex->CheckStopAuthentication(this, Message))
          return;
 

-   string const FinalRelease = MetaIndex->GetFinalFilename();
-   string const FinalReleasegpg = GetFinalFilename();
-   string const FinalInRelease = TransactionManager->GetFinalFilename();
-
-   if (RealFileExists(FinalReleasegpg) || RealFileExists(FinalInRelease))
-   {
-      std::string downgrade_msg;
-      strprintf(downgrade_msg, _("The repository '%s' is no longer signed."),
-                MetaIndex->Target.Description.c_str());
-      if(_config->FindB("Acquire::AllowDowngradeToInsecureRepositories"))
-      {
-         // meh, the users wants to take risks (we still mark the packages
-         // from this repository as unauthenticated)
-         _error->Warning("%s", downgrade_msg.c_str());
-         _error->Warning(_("This is normally not allowed, but the option "
-                           "Acquire::AllowDowngradeToInsecureRepositories was "
-                           "given to override it."));
-         Status = StatDone;
-      } else {
-        MessageInsecureRepository(true, downgrade_msg);
-        if (TransactionManager->IMSHit == false)
-           Rename(MetaIndex->DestFile, MetaIndex->DestFile + ".FAILED");
-        Item::Failed("Message: " + downgrade_msg, Cnf);
-         TransactionManager->AbortTransaction();
-         return;
-      }
-   }
-

    // ensures that a Release.gpg file in the lists/ is removed by the transaction
    TransactionManager->TransactionStageRemoval(this, DestFile);
 
    // ensures that a Release.gpg file in the lists/ is removed by the transaction
    TransactionManager->TransactionStageRemoval(this, DestFile);
 

-   // only allow going further if the users explicitely wants it
-   if (AllowInsecureRepositories(_("The repository '%s' is not signed."), MetaIndex->Target.Description, TransactionManager->MetaIndexParser, TransactionManager, this) == true)
+   // only allow going further if the user explicitly wants it
+   if (AllowInsecureRepositories(InsecureType::UNSIGNED, MetaIndex->Target.Description, TransactionManager->MetaIndexParser, TransactionManager, this) == true)

    {
    {

-      if (RealFileExists(FinalReleasegpg) || RealFileExists(FinalInRelease))
-      {
-        // open the last Release if we have it
-        if (TransactionManager->IMSHit == false)
-        {
-           TransactionManager->LastMetaIndexParser = TransactionManager->MetaIndexParser->UnloadedClone();
-           if (TransactionManager->LastMetaIndexParser != NULL)
-           {
-              _error->PushToStack();
-              if (RealFileExists(FinalInRelease))
-                 TransactionManager->LastMetaIndexParser->Load(FinalInRelease, NULL);
-              else
-                 TransactionManager->LastMetaIndexParser->Load(FinalRelease, NULL);
-              // its unlikely to happen, but if what we have is bad ignore it
-              if (_error->PendingError())
-              {
-                 delete TransactionManager->LastMetaIndexParser;
-                 TransactionManager->LastMetaIndexParser = NULL;
-              }
-              _error->RevertToStack();
-           }
-        }
-      }
+      string const FinalRelease = MetaIndex->GetFinalFilename();
+      string const FinalInRelease = TransactionManager->GetFinalFilename();
+      LoadLastMetaIndexParser(TransactionManager, FinalRelease, FinalInRelease);

 
       // we parse the indexes here because at this point the user wanted
       // a repository that may potentially harm him
 
       // we parse the indexes here because at this point the user wanted
       // a repository that may potentially harm him

-      if (TransactionManager->MetaIndexParser->Load(MetaIndex->DestFile, &ErrorText) == false || MetaIndex->VerifyVendor(Message) == false)
+      bool const GoodLoad = TransactionManager->MetaIndexParser->Load(MetaIndex->DestFile, &ErrorText);
+      if (MetaIndex->VerifyVendor(Message) == false)

         /* expired Release files are still a problem you need extra force for */;
       else
         /* expired Release files are still a problem you need extra force for */;
       else

-        MetaIndex->QueueIndexes(true);
+        TransactionManager->QueueIndexes(GoodLoad);

 
 

-      TransactionManager->TransactionStageCopy(MetaIndex, MetaIndex->DestFile, MetaIndex->GetFinalFilename());
+      TransactionManager->TransactionStageCopy(MetaIndex, MetaIndex->DestFile, FinalRelease);

    }
    }

+   else if (TransactionManager->IMSHit == false)
+      Rename(MetaIndex->DestFile, MetaIndex->DestFile + ".FAILED");

 
    // FIXME: this is used often (e.g. in pkgAcqIndexTrans) so refactor
    if (Cnf->LocalOnly == true ||
 
    // FIXME: this is used often (e.g. in pkgAcqIndexTrans) so refactor
    if (Cnf->LocalOnly == true ||


@@ -1694,6 +1975,21 @@ pkgAcqBaseIndex::pkgAcqBaseIndex(pkgAcquire * const Owner,
       IndexTarget const &Target)
 : pkgAcqTransactionItem(Owner, TransactionManager, Target), d(NULL)
 {
       IndexTarget const &Target)
 : pkgAcqTransactionItem(Owner, TransactionManager, Target), d(NULL)
 {

+}
+                                                                       /*}}}*/
+void pkgAcqBaseIndex::Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf)/*{{{*/
+{
+   pkgAcquire::Item::Failed(Message, Cnf);
+   if (Status != StatAuthError)
+      return;
+
+   ErrorText.append("Release file created at: ");
+   auto const timespec = TransactionManager->MetaIndexParser->GetDate();
+   if (timespec == 0)
+      ErrorText.append("<unknown>");
+   else
+      ErrorText.append(TimeRFC1123(timespec, true));
+   ErrorText.append("\n");

 }
                                                                        /*}}}*/
 pkgAcqBaseIndex::~pkgAcqBaseIndex() {}
 }
                                                                        /*}}}*/
 pkgAcqBaseIndex::~pkgAcqBaseIndex() {}


@@ -1708,56 +2004,64 @@ pkgAcqBaseIndex::~pkgAcqBaseIndex() {}
 pkgAcqDiffIndex::pkgAcqDiffIndex(pkgAcquire * const Owner,
                                  pkgAcqMetaClearSig * const TransactionManager,
                                  IndexTarget const &Target)
 pkgAcqDiffIndex::pkgAcqDiffIndex(pkgAcquire * const Owner,
                                  pkgAcqMetaClearSig * const TransactionManager,
                                  IndexTarget const &Target)

-   : pkgAcqBaseIndex(Owner, TransactionManager, Target), d(NULL), diffs(NULL)
+   : pkgAcqIndex(Owner, TransactionManager, Target, true), d(NULL), diffs(NULL)

 {
 {

+   // FIXME: Magic number as an upper bound on pdiffs we will reasonably acquire
+   ExpectedAdditionalItems = 40;

    Debug = _config->FindB("Debug::pkgAcquire::Diffs",false);
 
    Debug = _config->FindB("Debug::pkgAcquire::Diffs",false);
 

-   Desc.Owner = this;
-   Desc.Description = Target.Description + ".diff/Index";
-   Desc.ShortDesc = Target.ShortDesc;
-   Desc.URI = Target.URI + ".diff/Index";
-
-   DestFile = GetPartialFileNameFromURI(Desc.URI);
+   CompressionExtensions.clear();
+   {
+      std::vector<std::string> types = APT::Configuration::getCompressionTypes();
+      if (types.empty() == false)
+      {
+        std::ostringstream os;
+        std::copy_if(types.begin(), types.end()-1, std::ostream_iterator<std::string>(os, " "), [&](std::string const type) {
+              if (type == "uncompressed")
+                 return true;
+              return TransactionManager->MetaIndexParser->Exists(GetDiffIndexFileName(Target.MetaKey) + '.' + type);
+        });
+        os << *types.rbegin();
+        CompressionExtensions = os.str();
+      }
+   }
+   if (Target.Option(IndexTarget::COMPRESSIONTYPES).find("by-hash") != std::string::npos)
+      CompressionExtensions = "by-hash " + CompressionExtensions;
+   Init(GetDiffIndexURI(Target), GetDiffIndexFileName(Target.Description), Target.ShortDesc);

 
    if(Debug)
       std::clog << "pkgAcqDiffIndex: " << Desc.URI << std::endl;
 
    if(Debug)
       std::clog << "pkgAcqDiffIndex: " << Desc.URI << std::endl;

-
-   QueueURI(Desc);
-}
-                                                                       /*}}}*/
-// AcqIndex::Custom600Headers - Insert custom request headers          /*{{{*/
-// ---------------------------------------------------------------------
-/* The only header we use is the last-modified header. */
-string pkgAcqDiffIndex::Custom600Headers() const
-{
-   string const Final = GetFinalFilename();
-
-   if(Debug)
-      std::clog << "Custom600Header-IMS: " << Final << std::endl;
-
-   struct stat Buf;
-   if (stat(Final.c_str(),&Buf) != 0)
-      return "\nIndex-File: true";
-   
-   return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);

 }
                                                                        /*}}}*/
 void pkgAcqDiffIndex::QueueOnIMSHit() const                            /*{{{*/
 {
    // list cleanup needs to know that this file as well as the already
    // present index is ours, so we create an empty diff to save it for us
 }
                                                                        /*}}}*/
 void pkgAcqDiffIndex::QueueOnIMSHit() const                            /*{{{*/
 {
    // list cleanup needs to know that this file as well as the already
    // present index is ours, so we create an empty diff to save it for us

-   new pkgAcqIndexDiffs(Owner, TransactionManager, Target);
+   new pkgAcqIndexDiffs(Owner, TransactionManager, Target, UsedMirror, Target.URI);
+}
+                                                                       /*}}}*/
+static bool RemoveFileForBootstrapLinking(bool const Debug, std::string const &For, std::string const &Boot)/*{{{*/
+{
+   if (FileExists(Boot) && RemoveFile("Bootstrap-linking", Boot) == false)
+   {
+      if (Debug)
+        std::clog << "Bootstrap-linking for patching " << For
+           << " by removing stale " << Boot << " failed!" << std::endl;
+      return false;
+   }
+   return true;

 }
                                                                        /*}}}*/
 bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile)      /*{{{*/
 {
 }
                                                                        /*}}}*/
 bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile)      /*{{{*/
 {

+   ExpectedAdditionalItems = 0;

    // failing here is fine: our caller will take care of trying to
    // get the complete file if patching fails
    if(Debug)
       std::clog << "pkgAcqDiffIndex::ParseIndexDiff() " << IndexDiffFile
         << std::endl;
 
    // failing here is fine: our caller will take care of trying to
    // get the complete file if patching fails
    if(Debug)
       std::clog << "pkgAcqDiffIndex::ParseIndexDiff() " << IndexDiffFile
         << std::endl;
 

-   FileFd Fd(IndexDiffFile,FileFd::ReadOnly);
+   FileFd Fd(IndexDiffFile, FileFd::ReadOnly, FileFd::Extension);

    pkgTagFile TF(&Fd);
    if (Fd.IsOpen() == false || Fd.Failed())
       return false;
    pkgTagFile TF(&Fd);
    if (Fd.IsOpen() == false || Fd.Failed())
       return false;


@@ -1769,6 +2073,7 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile) /*{{{*/
    HashStringList ServerHashes;
    unsigned long long ServerSize = 0;
 
    HashStringList ServerHashes;
    unsigned long long ServerSize = 0;
 

+   auto const &posix = std::locale::classic();

    for (char const * const * type = HashString::SupportedHashes(); *type != NULL; ++type)
    {
       std::string tagname = *type;
    for (char const * const * type = HashString::SupportedHashes(); *type != NULL; ++type)
    {
       std::string tagname = *type;


@@ -1780,6 +2085,7 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile) /*{{{*/
       string hash;
       unsigned long long size;
       std::stringstream ss(tmp);
       string hash;
       unsigned long long size;
       std::stringstream ss(tmp);

+      ss.imbue(posix);

       ss >> hash >> size;
       if (unlikely(hash.empty() == true))
         continue;
       ss >> hash >> size;
       if (unlikely(hash.empty() == true))
         continue;


@@ -1803,7 +2109,7 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile) /*{{{*/
       if (Debug == true)
       {
         std::clog << "pkgAcqDiffIndex: " << IndexDiffFile << ": Index has different hashes than parser, probably older, so fail pdiffing" << std::endl;
       if (Debug == true)
       {
         std::clog << "pkgAcqDiffIndex: " << IndexDiffFile << ": Index has different hashes than parser, probably older, so fail pdiffing" << std::endl;

-         printHashSumComparision(CurrentPackagesFile, ServerHashes, TargetFileHashes);
+         printHashSumComparison(CurrentPackagesFile, ServerHashes, TargetFileHashes);

       }
       return false;
    }
       }
       return false;
    }


@@ -1833,10 +2139,18 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile)       /*{{{*/
       std::clog << "Server-Current: " << ServerHashes.find(NULL)->toStr() << " and we start at "
         << CurrentPackagesFile << " " << LocalHashes.FileSize() << " " << LocalHashes.find(NULL)->toStr() << std::endl;
 
       std::clog << "Server-Current: " << ServerHashes.find(NULL)->toStr() << " and we start at "
         << CurrentPackagesFile << " " << LocalHashes.FileSize() << " " << LocalHashes.find(NULL)->toStr() << std::endl;
 

+   // historically, older hashes have more info than newer ones, so start
+   // collecting with older ones first to avoid implementing complicated
+   // information merging techniques… a failure is after all always
+   // recoverable with a complete file and hashes aren't changed that often.
+   std::vector<char const *> types;
+   for (char const * const * type = HashString::SupportedHashes(); *type != NULL; ++type)
+      types.push_back(*type);
+

    // parse all of (provided) history
    vector<DiffInfo> available_patches;
    bool firstAcceptedHashes = true;
    // parse all of (provided) history
    vector<DiffInfo> available_patches;
    bool firstAcceptedHashes = true;

-   for (char const * const * type = HashString::SupportedHashes(); *type != NULL; ++type)
+   for (auto type = types.crbegin(); type != types.crend(); ++type)

    {
       if (LocalHashes.find(*type) == NULL)
         continue;
    {
       if (LocalHashes.find(*type) == NULL)
         continue;


@@ -1850,6 +2164,7 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile) /*{{{*/
       string hash, filename;
       unsigned long long size;
       std::stringstream ss(tmp);
       string hash, filename;
       unsigned long long size;
       std::stringstream ss(tmp);

+      ss.imbue(posix);

 
       while (ss >> hash >> size >> filename)
       {
 
       while (ss >> hash >> size >> filename)
       {


@@ -1894,7 +2209,7 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile) /*{{{*/
       return false;
    }
 
       return false;
    }
 

-   for (char const * const * type = HashString::SupportedHashes(); *type != NULL; ++type)
+   for (auto type = types.crbegin(); type != types.crend(); ++type)

    {
       if (LocalHashes.find(*type) == NULL)
         continue;
    {
       if (LocalHashes.find(*type) == NULL)
         continue;


@@ -1908,6 +2223,7 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile) /*{{{*/
       string hash, filename;
       unsigned long long size;
       std::stringstream ss(tmp);
       string hash, filename;
       unsigned long long size;
       std::stringstream ss(tmp);

+      ss.imbue(posix);

 
       while (ss >> hash >> size >> filename)
       {
 
       while (ss >> hash >> size >> filename)
       {


@@ -1934,7 +2250,7 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile) /*{{{*/
       }
    }
 
       }
    }
 

-   for (char const * const * type = HashString::SupportedHashes(); *type != NULL; ++type)
+   for (auto type = types.crbegin(); type != types.crend(); ++type)

    {
       std::string tagname = *type;
       tagname.append("-Download");
    {
       std::string tagname = *type;
       tagname.append("-Download");


@@ -1945,6 +2261,7 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile) /*{{{*/
       string hash, filename;
       unsigned long long size;
       std::stringstream ss(tmp);
       string hash, filename;
       unsigned long long size;
       std::stringstream ss(tmp);

+      ss.imbue(posix);

 
       // FIXME: all of pdiff supports only .gz compressed patches
       while (ss >> hash >> size >> filename)
 
       // FIXME: all of pdiff supports only .gz compressed patches
       while (ss >> hash >> size >> filename)


@@ -1996,6 +2313,17 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile)        /*{{{*/
       return false;
    }
 
       return false;
    }
 

+   for (auto const &patch: available_patches)
+      if (patch.result_hashes.usable() == false ||
+           patch.patch_hashes.usable() == false ||
+           patch.download_hashes.usable() == false)
+      {
+        if (Debug)
+           std::clog << "pkgAcqDiffIndex: " << IndexDiffFile << ": provides no usable hashes for " << patch.file
+              << " so fallback to complete download" << std::endl;
+        return false;
+      }
+

    // patching with too many files is rather slow compared to a fast download
    unsigned long const fileLimit = _config->FindI("Acquire::PDiffs::FileLimit", 0);
    if (fileLimit != 0 && fileLimit < available_patches.size())
    // patching with too many files is rather slow compared to a fast download
    unsigned long const fileLimit = _config->FindI("Acquire::PDiffs::FileLimit", 0);
    if (fileLimit != 0 && fileLimit < available_patches.size())


@@ -2007,18 +2335,37 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile)       /*{{{*/
    }
 
    // calculate the size of all patches we have to get
    }
 
    // calculate the size of all patches we have to get

-   // note that all sizes are uncompressed, while we download compressed files
-   unsigned long long patchesSize = 0;
-   for (std::vector<DiffInfo>::const_iterator cur = available_patches.begin();
-        cur != available_patches.end(); ++cur)
-      patchesSize += cur->patch_hashes.FileSize();
-   unsigned long long const sizeLimit = ServerSize * _config->FindI("Acquire::PDiffs::SizeLimit", 100);
-   if (sizeLimit > 0 && (sizeLimit/100) < patchesSize)
-   {
-      if (Debug)
-        std::clog << "Need " << patchesSize << " bytes (Limit is " << sizeLimit/100
-           << ") so fallback to complete download" << std::endl;
-      return false;
+   unsigned short const sizeLimitPercent = _config->FindI("Acquire::PDiffs::SizeLimit", 100);
+   if (sizeLimitPercent > 0)
+   {
+      unsigned long long downloadSize = std::accumulate(available_patches.begin(),
+           available_patches.end(), 0llu, [](unsigned long long const T, DiffInfo const &I) {
+           return T + I.download_hashes.FileSize();
+           });
+      if (downloadSize != 0)
+      {
+        unsigned long long downloadSizeIdx = 0;
+        auto const types = VectorizeString(Target.Option(IndexTarget::COMPRESSIONTYPES), ' ');
+        for (auto const &t : types)
+        {
+           std::string MetaKey = Target.MetaKey;
+           if (t != "uncompressed")
+              MetaKey += '.' + t;
+           HashStringList const hsl = GetExpectedHashesFor(MetaKey);
+           if (unlikely(hsl.usable() == false))
+              continue;
+           downloadSizeIdx = hsl.FileSize();
+           break;
+        }
+        unsigned long long const sizeLimit = downloadSizeIdx * sizeLimitPercent;
+        if ((sizeLimit/100) < downloadSize)
+        {
+           if (Debug)
+              std::clog << "Need " << downloadSize << " compressed bytes (Limit is " << (sizeLimit/100) << ", "
+                 << "original is " << downloadSizeIdx << ") so fallback to complete download" << std::endl;
+           return false;
+        }
+      }

    }
 
    // we have something, queue the diffs
    }
 
    // we have something, queue the diffs


@@ -2039,14 +2386,53 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile)       /*{{{*/
       pdiff_merge = (precedence != "merged");
    }
 
       pdiff_merge = (precedence != "merged");
    }
 

+   // clean the plate
+   {
+      std::string const Final = GetExistingFilename(CurrentPackagesFile);
+      if (unlikely(Final.empty())) // because we wouldn't be called in such a case
+        return false;
+      std::string const PartialFile = GetPartialFileNameFromURI(Target.URI);
+      std::string const PatchedFile = GetKeepCompressedFileName(PartialFile + "-patched", Target);
+      if (RemoveFileForBootstrapLinking(Debug, CurrentPackagesFile, PartialFile) == false ||
+           RemoveFileForBootstrapLinking(Debug, CurrentPackagesFile, PatchedFile) == false)
+        return false;
+      for (auto const &ext : APT::Configuration::getCompressorExtensions())
+      {
+        if (RemoveFileForBootstrapLinking(Debug, CurrentPackagesFile, PartialFile + ext) == false ||
+              RemoveFileForBootstrapLinking(Debug, CurrentPackagesFile, PatchedFile + ext) == false)
+           return false;
+      }
+      std::string const Ext = Final.substr(CurrentPackagesFile.length());
+      std::string const Partial = PartialFile + Ext;
+      if (symlink(Final.c_str(), Partial.c_str()) != 0)
+      {
+        if (Debug)
+           std::clog << "Bootstrap-linking for patching " << CurrentPackagesFile
+              << " by linking " << Final << " to " << Partial << " failed!" << std::endl;
+        return false;
+      }
+   }
+
+   std::string indexURI = Desc.URI;
+   auto const byhashidx = indexURI.find("/by-hash/");
+   if (byhashidx != std::string::npos)
+      indexURI = indexURI.substr(0, byhashidx - strlen(".diff"));
+   else
+   {
+      auto end = indexURI.length() - strlen(".diff/Index");
+      if (CurrentCompressionExtension != "uncompressed")
+        end -= (1 + CurrentCompressionExtension.length());
+      indexURI = indexURI.substr(0, end);
+   }
+

    if (pdiff_merge == false)
    if (pdiff_merge == false)

-      new pkgAcqIndexDiffs(Owner, TransactionManager, Target, available_patches);
+      new pkgAcqIndexDiffs(Owner, TransactionManager, Target, UsedMirror, indexURI, available_patches);

    else
    {
       diffs = new std::vector<pkgAcqIndexMergeDiffs*>(available_patches.size());
       for(size_t i = 0; i < available_patches.size(); ++i)
         (*diffs)[i] = new pkgAcqIndexMergeDiffs(Owner, TransactionManager,
    else
    {
       diffs = new std::vector<pkgAcqIndexMergeDiffs*>(available_patches.size());
       for(size_t i = 0; i < available_patches.size(); ++i)
         (*diffs)[i] = new pkgAcqIndexMergeDiffs(Owner, TransactionManager,

-               Target,
+               Target, UsedMirror, indexURI,

               available_patches[i],
               diffs);
    }
               available_patches[i],
               diffs);
    }


@@ -2059,8 +2445,11 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile)        /*{{{*/
                                                                        /*}}}*/
 void pkgAcqDiffIndex::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf)/*{{{*/
 {
                                                                        /*}}}*/
 void pkgAcqDiffIndex::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf)/*{{{*/
 {

-   Item::Failed(Message,Cnf);
+   if (CommonFailed(GetDiffIndexURI(Target), GetDiffIndexFileName(Target.Description), Message, Cnf))
+      return;
+

    Status = StatDone;
    Status = StatDone;

+   ExpectedAdditionalItems = 0;

 
    if(Debug)
       std::clog << "pkgAcqDiffIndex failed: " << Desc.URI << " with " << Message << std::endl
 
    if(Debug)
       std::clog << "pkgAcqDiffIndex failed: " << Desc.URI << " with " << Message << std::endl


@@ -2113,8 +2502,9 @@ pkgAcqDiffIndex::~pkgAcqDiffIndex()
 pkgAcqIndexDiffs::pkgAcqIndexDiffs(pkgAcquire * const Owner,
                                    pkgAcqMetaClearSig * const TransactionManager,
                                    IndexTarget const &Target,
 pkgAcqIndexDiffs::pkgAcqIndexDiffs(pkgAcquire * const Owner,
                                    pkgAcqMetaClearSig * const TransactionManager,
                                    IndexTarget const &Target,

+                                  std::string const &indexUsedMirror, std::string const &indexURI,

                                   vector<DiffInfo> const &diffs)
                                   vector<DiffInfo> const &diffs)

-   : pkgAcqBaseIndex(Owner, TransactionManager, Target), d(NULL),
+   : pkgAcqBaseIndex(Owner, TransactionManager, Target), indexURI(indexURI),

      available_patches(diffs)
 {
    DestFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI), Target);
      available_patches(diffs)
 {
    DestFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI), Target);


@@ -2125,6 +2515,12 @@ pkgAcqIndexDiffs::pkgAcqIndexDiffs(pkgAcquire * const Owner,
    Description = Target.Description;
    Desc.ShortDesc = Target.ShortDesc;
 
    Description = Target.Description;
    Desc.ShortDesc = Target.ShortDesc;
 

+   UsedMirror = indexUsedMirror;
+   if (UsedMirror == "DIRECT")
+      UsedMirror.clear();
+   else if (UsedMirror.empty() == false && Description.find(" ") != string::npos)
+      Description.replace(0, Description.find(" "), UsedMirror);
+

    if(available_patches.empty() == true)
    {
       // we are done (yeah!), check hashes against the final file
    if(available_patches.empty() == true)
    {
       // we are done (yeah!), check hashes against the final file


@@ -2133,13 +2529,6 @@ pkgAcqIndexDiffs::pkgAcqIndexDiffs(pkgAcquire * const Owner,
    }
    else
    {
    }
    else
    {

-      if (BootstrapPDiffWith(GetPartialFileNameFromURI(Target.URI), GetFinalFilename(), Target) == false)
-      {
-        Failed("Bootstrapping of " + DestFile + " failed", NULL);
-        return;
-      }
-
-      // get the next diff

       State = StateFetchDiff;
       QueueNextDiff();
    }
       State = StateFetchDiff;
       QueueNextDiff();
    }


@@ -2147,7 +2536,7 @@ pkgAcqIndexDiffs::pkgAcqIndexDiffs(pkgAcquire * const Owner,
                                                                        /*}}}*/
 void pkgAcqIndexDiffs::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf)/*{{{*/
 {
                                                                        /*}}}*/
 void pkgAcqIndexDiffs::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf)/*{{{*/
 {

-   Item::Failed(Message,Cnf);
+   pkgAcqBaseIndex::Failed(Message,Cnf);

    Status = StatDone;
 
    DestFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI), Target);
    Status = StatDone;
 
    DestFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI), Target);


@@ -2157,7 +2546,10 @@ void pkgAcqIndexDiffs::Failed(string const &Message,pkgAcquire::MethodConfig con
    RenameOnError(PDiffError);
    std::string const patchname = GetDiffsPatchFileName(DestFile);
    if (RealFileExists(patchname))
    RenameOnError(PDiffError);
    std::string const patchname = GetDiffsPatchFileName(DestFile);
    if (RealFileExists(patchname))

-      rename(patchname.c_str(), std::string(patchname + ".FAILED").c_str());
+      Rename(patchname, patchname + ".FAILED");
+   std::string const UnpatchedFile = GetExistingFilename(GetPartialFileNameFromURI(Target.URI));
+   if (UnpatchedFile.empty() == false && FileExists(UnpatchedFile))
+      Rename(UnpatchedFile, UnpatchedFile + ".FAILED");

    new pkgAcqIndex(Owner, TransactionManager, Target);
    Finish();
 }
    new pkgAcqIndex(Owner, TransactionManager, Target);
    Finish();
 }


@@ -2174,13 +2566,7 @@ void pkgAcqIndexDiffs::Finish(bool allDone)
    // the file will be cleaned
    if(allDone)
    {
    // the file will be cleaned
    if(allDone)
    {

-      std::string Final = GetFinalFilename();
-      if (Target.KeepCompressed)
-      {
-        std::string const ext = flExtension(DestFile);
-        if (ext.empty() == false)
-           Final.append(".").append(ext);
-      }
+      std::string const Final = GetKeepCompressedFileName(GetFinalFilename(), Target);

       TransactionManager->TransactionStageCopy(this, DestFile, Final);
 
       // this is for the "real" finish
       TransactionManager->TransactionStageCopy(this, DestFile, Final);
 
       // this is for the "real" finish


@@ -2205,29 +2591,28 @@ void pkgAcqIndexDiffs::Finish(bool allDone)
 bool pkgAcqIndexDiffs::QueueNextDiff()                                 /*{{{*/
 {
    // calc sha1 of the just patched file
 bool pkgAcqIndexDiffs::QueueNextDiff()                                 /*{{{*/
 {
    // calc sha1 of the just patched file

-   std::string const FinalFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI), Target);
-   if(!FileExists(FinalFile))
+   std::string const PartialFile = GetExistingFilename(GetPartialFileNameFromURI(Target.URI));
+   if(unlikely(PartialFile.empty()))

    {
    {

-      Failed("Message: No FinalFile " + FinalFile + " available", NULL);
+      Failed("Message: The file " + GetPartialFileNameFromURI(Target.URI) + " isn't available", NULL);

       return false;
    }
 
       return false;
    }
 

-   FileFd fd(FinalFile, FileFd::ReadOnly, FileFd::Extension);
+   FileFd fd(PartialFile, FileFd::ReadOnly, FileFd::Extension);

    Hashes LocalHashesCalc;
    LocalHashesCalc.AddFD(fd);
    HashStringList const LocalHashes = LocalHashesCalc.GetHashStringList();
 
    if(Debug)
    Hashes LocalHashesCalc;
    LocalHashesCalc.AddFD(fd);
    HashStringList const LocalHashes = LocalHashesCalc.GetHashStringList();
 
    if(Debug)

-      std::clog << "QueueNextDiff: " << FinalFile << " (" << LocalHashes.find(NULL)->toStr() << ")" << std::endl;
+      std::clog << "QueueNextDiff: " << PartialFile << " (" << LocalHashes.find(NULL)->toStr() << ")" << std::endl;

 
    HashStringList const TargetFileHashes = GetExpectedHashesFor(Target.MetaKey);
    if (unlikely(LocalHashes.usable() == false || TargetFileHashes.usable() == false))
    {
 
    HashStringList const TargetFileHashes = GetExpectedHashesFor(Target.MetaKey);
    if (unlikely(LocalHashes.usable() == false || TargetFileHashes.usable() == false))
    {

-      Failed("Local/Expected hashes are not usable", NULL);
+      Failed("Local/Expected hashes are not usable for " + PartialFile, NULL);

       return false;
    }
 
       return false;
    }
 

-

    // final file reached before all patches are applied
    if(LocalHashes == TargetFileHashes)
    {
    // final file reached before all patches are applied
    if(LocalHashes == TargetFileHashes)
    {


@@ -2237,24 +2622,20 @@ bool pkgAcqIndexDiffs::QueueNextDiff()                                  /*{{{*/
 
    // remove all patches until the next matching patch is found
    // this requires the Index file to be ordered
 
    // remove all patches until the next matching patch is found
    // this requires the Index file to be ordered

-   for(vector<DiffInfo>::iterator I = available_patches.begin();
-       available_patches.empty() == false &&
-         I != available_patches.end() &&
-         I->result_hashes != LocalHashes;
-       ++I)
-   {
-      available_patches.erase(I);
-   }
+   available_patches.erase(available_patches.begin(),
+        std::find_if(available_patches.begin(), available_patches.end(), [&](DiffInfo const &I) {
+           return I.result_hashes == LocalHashes;
+           }));

 
    // error checking and falling back if no patch was found
    if(available_patches.empty() == true)
    {
 
    // error checking and falling back if no patch was found
    if(available_patches.empty() == true)
    {

-      Failed("No patches left to reach target", NULL);
+      Failed("No patches left to reach target for " + PartialFile, NULL);

       return false;
    }
 
    // queue the right diff
       return false;
    }
 
    // queue the right diff

-   Desc.URI = Target.URI + ".diff/" + available_patches[0].file + ".gz";
+   Desc.URI = indexURI + ".diff/" + available_patches[0].file + ".gz";

    Desc.Description = Description + " " + available_patches[0].file + string(".pdiff");
    DestFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI + ".diff/" + available_patches[0].file), Target);
 
    Desc.Description = Description + " " + available_patches[0].file + string(".pdiff");
    DestFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI + ".diff/" + available_patches[0].file), Target);
 


@@ -2269,55 +2650,51 @@ bool pkgAcqIndexDiffs::QueueNextDiff()                                  /*{{{*/
 void pkgAcqIndexDiffs::Done(string const &Message, HashStringList const &Hashes,       /*{{{*/
                            pkgAcquire::MethodConfig const * const Cnf)
 {
 void pkgAcqIndexDiffs::Done(string const &Message, HashStringList const &Hashes,       /*{{{*/
                            pkgAcquire::MethodConfig const * const Cnf)
 {

-   if(Debug)
+   if (Debug)

       std::clog << "pkgAcqIndexDiffs::Done(): " << Desc.URI << std::endl;
 
    Item::Done(Message, Hashes, Cnf);
 
       std::clog << "pkgAcqIndexDiffs::Done(): " << Desc.URI << std::endl;
 
    Item::Done(Message, Hashes, Cnf);
 

-   std::string const FinalFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI), Target);
-   std::string const PatchFile = GetDiffsPatchFileName(FinalFile);
-
-   // success in downloading a diff, enter ApplyDiff state
-   if(State == StateFetchDiff)
-   {
-      Rename(DestFile, PatchFile);
-
-      if(Debug)
-        std::clog << "Sending to rred method: " << FinalFile << std::endl;
-
-      State = StateApplyDiff;
-      Local = true;
-      Desc.URI = "rred:" + FinalFile;
-      QueueURI(Desc);
-      SetActiveSubprocess("rred");
-      return;
-   }
+   std::string const UncompressedUnpatchedFile = GetPartialFileNameFromURI(Target.URI);
+   std::string const UnpatchedFile = GetExistingFilename(UncompressedUnpatchedFile);
+   std::string const PatchFile = GetDiffsPatchFileName(UnpatchedFile);
+   std::string const PatchedFile = GetKeepCompressedFileName(UncompressedUnpatchedFile, Target);

 
 

-   // success in download/apply a diff, queue next (if needed)
-   if(State == StateApplyDiff)
+   switch (State)

    {
    {

-      // remove the just applied patch
-      available_patches.erase(available_patches.begin());
-      RemoveFile("pkgAcqIndexDiffs::Done", PatchFile);
-
-      // move into place
-      if(Debug)
-      {
-        std::clog << "Moving patched file in place: " << std::endl
-                  << DestFile << " -> " << FinalFile << std::endl;
-      }
-      Rename(DestFile,FinalFile);
-      chmod(FinalFile.c_str(),0644);
-
-      // see if there is more to download
-      if(available_patches.empty() == false) {
-        new pkgAcqIndexDiffs(Owner, TransactionManager, Target,
-                             available_patches);
-        return Finish();
-      } else 
-         // update
-         DestFile = FinalFile;
-        return Finish(true);
+      // success in downloading a diff, enter ApplyDiff state
+      case StateFetchDiff:
+        Rename(DestFile, PatchFile);
+        DestFile = GetKeepCompressedFileName(UncompressedUnpatchedFile + "-patched", Target);
+        if(Debug)
+           std::clog << "Sending to rred method: " << UnpatchedFile << std::endl;
+        State = StateApplyDiff;
+        Local = true;
+        Desc.URI = "rred:" + UnpatchedFile;
+        QueueURI(Desc);
+        SetActiveSubprocess("rred");
+        return;
+      // success in download/apply a diff, queue next (if needed)
+      case StateApplyDiff:
+        // remove the just applied patch and base file
+        available_patches.erase(available_patches.begin());
+        RemoveFile("pkgAcqIndexDiffs::Done", PatchFile);
+        RemoveFile("pkgAcqIndexDiffs::Done", UnpatchedFile);
+        if(Debug)
+           std::clog << "Moving patched file in place: " << std::endl
+              << DestFile << " -> " << PatchedFile << std::endl;
+        Rename(DestFile, PatchedFile);
+
+        // see if there is more to download
+        if(available_patches.empty() == false)
+        {
+           new pkgAcqIndexDiffs(Owner, TransactionManager, Target, UsedMirror, indexURI, available_patches);
+           Finish();
+        } else {
+           DestFile = PatchedFile;
+           Finish(true);
+        }
+        return;

    }
 }
                                                                        /*}}}*/
    }
 }
                                                                        /*}}}*/


@@ -2326,9 +2703,10 @@ std::string pkgAcqIndexDiffs::Custom600Headers() const                   /*{{{*/
    if(State != StateApplyDiff)
       return pkgAcqBaseIndex::Custom600Headers();
    std::ostringstream patchhashes;
    if(State != StateApplyDiff)
       return pkgAcqBaseIndex::Custom600Headers();
    std::ostringstream patchhashes;

-   HashStringList const ExpectedHashes = available_patches[0].patch_hashes;
-   for (HashStringList::const_iterator hs = ExpectedHashes.begin(); hs != ExpectedHashes.end(); ++hs)
-      patchhashes <<  "\nPatch-0-" << hs->HashType() << "-Hash: " << hs->HashValue();
+   for (auto && hs : available_patches[0].result_hashes)
+      patchhashes <<  "\nStart-" << hs.HashType() << "-Hash: " << hs.HashValue();
+   for (auto && hs : available_patches[0].patch_hashes)
+      patchhashes <<  "\nPatch-0-" << hs.HashType() << "-Hash: " << hs.HashValue();

    patchhashes << pkgAcqBaseIndex::Custom600Headers();
    return patchhashes.str();
 }
    patchhashes << pkgAcqBaseIndex::Custom600Headers();
    return patchhashes.str();
 }


@@ -2339,21 +2717,26 @@ pkgAcqIndexDiffs::~pkgAcqIndexDiffs() {}
 pkgAcqIndexMergeDiffs::pkgAcqIndexMergeDiffs(pkgAcquire * const Owner,
                                              pkgAcqMetaClearSig * const TransactionManager,
                                              IndexTarget const &Target,
 pkgAcqIndexMergeDiffs::pkgAcqIndexMergeDiffs(pkgAcquire * const Owner,
                                              pkgAcqMetaClearSig * const TransactionManager,
                                              IndexTarget const &Target,

+                                            std::string const &indexUsedMirror, std::string const &indexURI,

                                              DiffInfo const &patch,
                                              std::vector<pkgAcqIndexMergeDiffs*> const * const allPatches)
                                              DiffInfo const &patch,
                                              std::vector<pkgAcqIndexMergeDiffs*> const * const allPatches)

-  : pkgAcqBaseIndex(Owner, TransactionManager, Target), d(NULL),
-     patch(patch), allPatches(allPatches), State(StateFetchDiff)
+  : pkgAcqBaseIndex(Owner, TransactionManager, Target), indexURI(indexURI),
+    patch(patch), allPatches(allPatches), State(StateFetchDiff)

 {
    Debug = _config->FindB("Debug::pkgAcquire::Diffs",false);
 
 {
    Debug = _config->FindB("Debug::pkgAcquire::Diffs",false);
 

-   Desc.Owner = this;

    Description = Target.Description;
    Description = Target.Description;

-   Desc.ShortDesc = Target.ShortDesc;
+   UsedMirror = indexUsedMirror;
+   if (UsedMirror == "DIRECT")
+      UsedMirror.clear();
+   else if (UsedMirror.empty() == false && Description.find(" ") != string::npos)
+      Description.replace(0, Description.find(" "), UsedMirror);

 
 

-   Desc.URI = Target.URI + ".diff/" + patch.file + ".gz";
-   Desc.Description = Description + " " + patch.file + string(".pdiff");
-
-   DestFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI + ".diff/" + patch.file), Target);
+   Desc.Owner = this;
+   Desc.ShortDesc = Target.ShortDesc;
+   Desc.URI = indexURI + ".diff/" + patch.file + ".gz";
+   Desc.Description = Description + " " + patch.file + ".pdiff";
+   DestFile = GetPartialFileNameFromURI(Target.URI + ".diff/" + patch.file + ".gz");

 
    if(Debug)
       std::clog << "pkgAcqIndexMergeDiffs: " << Desc.URI << std::endl;
 
    if(Debug)
       std::clog << "pkgAcqIndexMergeDiffs: " << Desc.URI << std::endl;


@@ -2366,7 +2749,7 @@ void pkgAcqIndexMergeDiffs::Failed(string const &Message,pkgAcquire::MethodConfi
    if(Debug)
       std::clog << "pkgAcqIndexMergeDiffs failed: " << Desc.URI << " with " << Message << std::endl;
 
    if(Debug)
       std::clog << "pkgAcqIndexMergeDiffs failed: " << Desc.URI << " with " << Message << std::endl;
 

-   Item::Failed(Message,Cnf);
+   pkgAcqBaseIndex::Failed(Message,Cnf);

    Status = StatDone;
 
    // check if we are the first to fail, otherwise we are done here
    Status = StatDone;
 
    // check if we are the first to fail, otherwise we are done here


@@ -2374,19 +2757,23 @@ void pkgAcqIndexMergeDiffs::Failed(string const &Message,pkgAcquire::MethodConfi
    for (std::vector<pkgAcqIndexMergeDiffs *>::const_iterator I = allPatches->begin();
         I != allPatches->end(); ++I)
       if ((*I)->State == StateErrorDiff)
    for (std::vector<pkgAcqIndexMergeDiffs *>::const_iterator I = allPatches->begin();
         I != allPatches->end(); ++I)
       if ((*I)->State == StateErrorDiff)

+      {
+        State = StateErrorDiff;

         return;
         return;

+      }

 
    // first failure means we should fallback
    State = StateErrorDiff;
    if (Debug)
       std::clog << "Falling back to normal index file acquire" << std::endl;
 
    // first failure means we should fallback
    State = StateErrorDiff;
    if (Debug)
       std::clog << "Falling back to normal index file acquire" << std::endl;

-   DestFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI), Target);

    RenameOnError(PDiffError);
    RenameOnError(PDiffError);

-   std::string const patchname = GetMergeDiffsPatchFileName(DestFile, patch.file);
-   if (RealFileExists(patchname))
-      rename(patchname.c_str(), std::string(patchname + ".FAILED").c_str());
-   new pkgAcqIndex(Owner, TransactionManager, Target);
+   if (RealFileExists(DestFile))
+      Rename(DestFile, DestFile + ".FAILED");
+   std::string const UnpatchedFile = GetExistingFilename(GetPartialFileNameFromURI(Target.URI));
+   if (UnpatchedFile.empty() == false && FileExists(UnpatchedFile))
+      Rename(UnpatchedFile, UnpatchedFile + ".FAILED");

    DestFile.clear();
    DestFile.clear();

+   new pkgAcqIndex(Owner, TransactionManager, Target);

 }
                                                                        /*}}}*/
 void pkgAcqIndexMergeDiffs::Done(string const &Message, HashStringList const &Hashes,  /*{{{*/
 }
                                                                        /*}}}*/
 void pkgAcqIndexMergeDiffs::Done(string const &Message, HashStringList const &Hashes,  /*{{{*/


@@ -2397,67 +2784,73 @@ void pkgAcqIndexMergeDiffs::Done(string const &Message, HashStringList const &Ha
 
    Item::Done(Message, Hashes, Cnf);
 
 
    Item::Done(Message, Hashes, Cnf);
 

-   std::string const UncompressedFinalFile = GetPartialFileNameFromURI(Target.URI);
-   std::string const FinalFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI), Target);
-   if (State == StateFetchDiff)
+   if (std::any_of(allPatches->begin(), allPatches->end(),
+           [](pkgAcqIndexMergeDiffs const * const P) { return P->State == StateErrorDiff; }))

    {
    {

-      Rename(DestFile, GetMergeDiffsPatchFileName(FinalFile, patch.file));
-
-      // check if this is the last completed diff
-      State = StateDoneDiff;
-      for (std::vector<pkgAcqIndexMergeDiffs *>::const_iterator I = allPatches->begin();
-           I != allPatches->end(); ++I)
-        if ((*I)->State != StateDoneDiff)
-        {
-           if(Debug)
-              std::clog << "Not the last done diff in the batch: " << Desc.URI << std::endl;
-           return;
-        }
-
-      // this is the last completed diff, so we are ready to apply now
-      State = StateApplyDiff;
-
-      if (BootstrapPDiffWith(UncompressedFinalFile, GetFinalFilename(), Target) == false)
-      {
-        Failed("Bootstrapping of " + DestFile + " failed", NULL);
-        return;
-      }
-

       if(Debug)
       if(Debug)

-        std::clog << "Sending to rred method: " << FinalFile << std::endl;
-
-      Local = true;
-      Desc.URI = "rred:" + FinalFile;
-      QueueURI(Desc);
-      SetActiveSubprocess("rred");
+        std::clog << "Another patch failed already, no point in processing this one." << std::endl;
+      State = StateErrorDiff;

       return;
    }
       return;
    }

-   // success in download/apply all diffs, clean up
-   else if (State == StateApplyDiff)
-   {
-      // move the result into place
-      std::string const Final = GetKeepCompressedFileName(GetFinalFilename(), Target);
-      if(Debug)
-        std::clog << "Queue patched file in place: " << std::endl
-                  << DestFile << " -> " << Final << std::endl;

 
 

-      // queue for copy by the transaction manager
-      TransactionManager->TransactionStageCopy(this, DestFile, Final);
+   std::string const UncompressedUnpatchedFile = GetPartialFileNameFromURI(Target.URI);
+   std::string const UnpatchedFile = GetExistingFilename(UncompressedUnpatchedFile);
+   if (UnpatchedFile.empty())
+   {
+      _error->Fatal("Unpatched file %s doesn't exist (anymore)!", UncompressedUnpatchedFile.c_str());
+      State = StateErrorDiff;
+      return;
+   }
+   std::string const PatchFile = GetMergeDiffsPatchFileName(UnpatchedFile, patch.file);
+   std::string const PatchedFile = GetKeepCompressedFileName(UncompressedUnpatchedFile, Target);

 
 

-      // ensure the ed's are gone regardless of list-cleanup
-      for (std::vector<pkgAcqIndexMergeDiffs *>::const_iterator I = allPatches->begin();
-           I != allPatches->end(); ++I)
-      {
-        std::string const PartialFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI), Target);
-        std::string const patch = GetMergeDiffsPatchFileName(PartialFile, (*I)->patch.file);
-        RemoveFile("pkgAcqIndexMergeDiffs::Done", patch);
-      }
-      RemoveFile("pkgAcqIndexMergeDiffs::Done", FinalFile);
+   switch (State)
+   {
+      case StateFetchDiff:
+        Rename(DestFile, PatchFile);

 
 

-      // all set and done
-      Complete = true;
-      if(Debug)
-        std::clog << "allDone: " << DestFile << "\n" << std::endl;
+        // check if this is the last completed diff
+        State = StateDoneDiff;
+        for (std::vector<pkgAcqIndexMergeDiffs *>::const_iterator I = allPatches->begin();
+              I != allPatches->end(); ++I)
+           if ((*I)->State != StateDoneDiff)
+           {
+              if(Debug)
+                 std::clog << "Not the last done diff in the batch: " << Desc.URI << std::endl;
+              return;
+           }
+        // this is the last completed diff, so we are ready to apply now
+        DestFile = GetKeepCompressedFileName(UncompressedUnpatchedFile + "-patched", Target);
+        if(Debug)
+           std::clog << "Sending to rred method: " << UnpatchedFile << std::endl;
+        State = StateApplyDiff;
+        Local = true;
+        Desc.URI = "rred:" + UnpatchedFile;
+        QueueURI(Desc);
+        SetActiveSubprocess("rred");
+        return;
+      case StateApplyDiff:
+        // success in download & apply all diffs, finialize and clean up
+        if(Debug)
+           std::clog << "Queue patched file in place: " << std::endl
+              << DestFile << " -> " << PatchedFile << std::endl;
+
+        // queue for copy by the transaction manager
+        TransactionManager->TransactionStageCopy(this, DestFile, GetKeepCompressedFileName(GetFinalFilename(), Target));
+
+        // ensure the ed's are gone regardless of list-cleanup
+        for (std::vector<pkgAcqIndexMergeDiffs *>::const_iterator I = allPatches->begin();
+              I != allPatches->end(); ++I)
+           RemoveFile("pkgAcqIndexMergeDiffs::Done", GetMergeDiffsPatchFileName(UnpatchedFile, (*I)->patch.file));
+        RemoveFile("pkgAcqIndexMergeDiffs::Done", UnpatchedFile);
+
+        // all set and done
+        Complete = true;
+        if(Debug)
+           std::clog << "allDone: " << DestFile << "\n" << std::endl;
+        return;
+      case StateDoneDiff: _error->Fatal("Done called for %s which is in an invalid Done state", PatchFile.c_str()); break;
+      case StateErrorDiff: _error->Fatal("Done called for %s which is in an invalid Error state", PatchFile.c_str()); break;

    }
 }
                                                                        /*}}}*/
    }
 }
                                                                        /*}}}*/


@@ -2467,12 +2860,14 @@ std::string pkgAcqIndexMergeDiffs::Custom600Headers() const             /*{{{*/
       return pkgAcqBaseIndex::Custom600Headers();
    std::ostringstream patchhashes;
    unsigned int seen_patches = 0;
       return pkgAcqBaseIndex::Custom600Headers();
    std::ostringstream patchhashes;
    unsigned int seen_patches = 0;

+   for (auto && hs : (*allPatches)[0]->patch.result_hashes)
+      patchhashes <<  "\nStart-" << hs.HashType() << "-Hash: " << hs.HashValue();

    for (std::vector<pkgAcqIndexMergeDiffs *>::const_iterator I = allPatches->begin();
         I != allPatches->end(); ++I)
    {
       HashStringList const ExpectedHashes = (*I)->patch.patch_hashes;
       for (HashStringList::const_iterator hs = ExpectedHashes.begin(); hs != ExpectedHashes.end(); ++hs)
    for (std::vector<pkgAcqIndexMergeDiffs *>::const_iterator I = allPatches->begin();
         I != allPatches->end(); ++I)
    {
       HashStringList const ExpectedHashes = (*I)->patch.patch_hashes;
       for (HashStringList::const_iterator hs = ExpectedHashes.begin(); hs != ExpectedHashes.end(); ++hs)

-        patchhashes <<  "\nPatch-" << seen_patches << "-" << hs->HashType() << "-Hash: " << hs->HashValue();
+        patchhashes <<  "\nPatch-" << std::to_string(seen_patches) << "-" << hs->HashType() << "-Hash: " << hs->HashValue();

       ++seen_patches;
    }
    patchhashes << pkgAcqBaseIndex::Custom600Headers();
       ++seen_patches;
    }
    patchhashes << pkgAcqBaseIndex::Custom600Headers();


@@ -2484,10 +2879,12 @@ pkgAcqIndexMergeDiffs::~pkgAcqIndexMergeDiffs() {}
 // AcqIndex::AcqIndex - Constructor                                    /*{{{*/
 pkgAcqIndex::pkgAcqIndex(pkgAcquire * const Owner,
                          pkgAcqMetaClearSig * const TransactionManager,
 // AcqIndex::AcqIndex - Constructor                                    /*{{{*/
 pkgAcqIndex::pkgAcqIndex(pkgAcquire * const Owner,
                          pkgAcqMetaClearSig * const TransactionManager,

-                         IndexTarget const &Target)
+                         IndexTarget const &Target, bool const Derived)

    : pkgAcqBaseIndex(Owner, TransactionManager, Target), d(NULL), Stage(STAGE_DOWNLOAD),
    CompressionExtensions(Target.Option(IndexTarget::COMPRESSIONTYPES))
 {
    : pkgAcqBaseIndex(Owner, TransactionManager, Target), d(NULL), Stage(STAGE_DOWNLOAD),
    CompressionExtensions(Target.Option(IndexTarget::COMPRESSIONTYPES))
 {

+   if (Derived)
+      return;

    Init(Target.URI, Target.Description, Target.ShortDesc);
 
    if(_config->FindB("Debug::Acquire::Transaction", false) == true)
    Init(Target.URI, Target.Description, Target.ShortDesc);
 
    if(_config->FindB("Debug::Acquire::Transaction", false) == true)


@@ -2527,13 +2924,15 @@ void pkgAcqIndex::Init(string const &URI, string const &URIDesc,
    else if (CurrentCompressionExtension == "by-hash")
    {
       NextCompressionExtension(CurrentCompressionExtension, CompressionExtensions, true);
    else if (CurrentCompressionExtension == "by-hash")
    {
       NextCompressionExtension(CurrentCompressionExtension, CompressionExtensions, true);

-      if(unlikely(TransactionManager->MetaIndexParser == NULL || CurrentCompressionExtension.empty()))
+      if(unlikely(CurrentCompressionExtension.empty()))

         return;
       if (CurrentCompressionExtension != "uncompressed")
       {
         Desc.URI = URI + '.' + CurrentCompressionExtension;
         DestFile = DestFile + '.' + CurrentCompressionExtension;
       }
         return;
       if (CurrentCompressionExtension != "uncompressed")
       {
         Desc.URI = URI + '.' + CurrentCompressionExtension;
         DestFile = DestFile + '.' + CurrentCompressionExtension;
       }

+      else
+        Desc.URI = URI;

 
       HashStringList const Hashes = GetExpectedHashes();
       HashString const * const TargetHash = Hashes.find(NULL);
 
       HashStringList const Hashes = GetExpectedHashes();
       HashString const * const TargetHash = Hashes.find(NULL);


@@ -2556,6 +2955,9 @@ void pkgAcqIndex::Init(string const &URI, string const &URIDesc,
       DestFile = DestFile + '.' + CurrentCompressionExtension;
    }
 
       DestFile = DestFile + '.' + CurrentCompressionExtension;
    }
 

+   // store file size of the download to ensure the fetcher gives
+   // accurate progress reporting
+   FileSize = GetExpectedHashes().FileSize();

 
    Desc.Description = URIDesc;
    Desc.Owner = this;
 
    Desc.Description = URIDesc;
    Desc.Owner = this;


@@ -2569,12 +2971,17 @@ void pkgAcqIndex::Init(string const &URI, string const &URIDesc,
 /* The only header we use is the last-modified header. */
 string pkgAcqIndex::Custom600Headers() const
 {
 /* The only header we use is the last-modified header. */
 string pkgAcqIndex::Custom600Headers() const
 {

-   string Final = GetFinalFilename();

 
    string msg = "\nIndex-File: true";
 
    string msg = "\nIndex-File: true";

-   struct stat Buf;
-   if (stat(Final.c_str(),&Buf) == 0)
-      msg += "\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
+
+   if (TransactionManager->LastMetaIndexParser == NULL)
+   {
+      std::string const Final = GetFinalFilename();
+
+      struct stat Buf;
+      if (stat(Final.c_str(),&Buf) == 0)
+        msg += "\nLast-Modified: " + TimeRFC1123(Buf.st_mtime, false);
+   }

 
    if(Target.IsOptional)
       msg += "\nFail-Ignore: true";
 
    if(Target.IsOptional)
       msg += "\nFail-Ignore: true";


@@ -2583,20 +2990,40 @@ string pkgAcqIndex::Custom600Headers() const
 }
                                                                        /*}}}*/
 // AcqIndex::Failed - getting the indexfile failed                     /*{{{*/
 }
                                                                        /*}}}*/
 // AcqIndex::Failed - getting the indexfile failed                     /*{{{*/

-void pkgAcqIndex::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf)
+bool pkgAcqIndex::CommonFailed(std::string const &TargetURI, std::string const TargetDesc,
+      std::string const &Message, pkgAcquire::MethodConfig const * const Cnf)

 {
 {

-   Item::Failed(Message,Cnf);
+   pkgAcqBaseIndex::Failed(Message,Cnf);
+
+   if (UsedMirror.empty() == false && UsedMirror != "DIRECT" &&
+        LookupTag(Message, "FailReason") == "HttpError404")
+   {
+      UsedMirror = "DIRECT";
+      if (Desc.URI.find("/by-hash/") != std::string::npos)
+        CompressionExtensions = "by-hash " + CompressionExtensions;
+      else
+        CompressionExtensions = CurrentCompressionExtension + ' ' + CompressionExtensions;
+      Init(TargetURI, TargetDesc, Desc.ShortDesc);
+      Status = StatIdle;
+      return true;
+   }

 
    // authorisation matches will not be fixed by other compression types
    if (Status != StatAuthError)
    {
       if (CompressionExtensions.empty() == false)
       {
 
    // authorisation matches will not be fixed by other compression types
    if (Status != StatAuthError)
    {
       if (CompressionExtensions.empty() == false)
       {

-        Init(Target.URI, Desc.Description, Desc.ShortDesc);
+        Init(TargetURI, Desc.Description, Desc.ShortDesc);

         Status = StatIdle;
         Status = StatIdle;

-        return;
+        return true;

       }
    }
       }
    }

+   return false;
+}
+void pkgAcqIndex::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf)
+{
+   if (CommonFailed(Target.URI, Target.Description, Message, Cnf))
+      return;

 
    if(Target.IsOptional && GetExpectedHashes().empty() && Stage == STAGE_DOWNLOAD)
       Status = StatDone;
 
    if(Target.IsOptional && GetExpectedHashes().empty() && Stage == STAGE_DOWNLOAD)
       Status = StatDone;


@@ -2604,20 +3031,6 @@ void pkgAcqIndex::Failed(string const &Message,pkgAcquire::MethodConfig const *
       TransactionManager->AbortTransaction();
 }
                                                                        /*}}}*/
       TransactionManager->AbortTransaction();
 }
                                                                        /*}}}*/

-// AcqIndex::ReverifyAfterIMS - Reverify index after an ims-hit                /*{{{*/
-void pkgAcqIndex::ReverifyAfterIMS()
-{
-   // update destfile to *not* include the compression extension when doing
-   // a reverify (as its uncompressed on disk already)
-   DestFile = GetCompressedFileName(Target, GetPartialFileNameFromURI(Target.URI), CurrentCompressionExtension);
-
-   // copy FinalFile into partial/ so that we check the hash again
-   string FinalFile = GetFinalFilename();
-   Stage = STAGE_DECOMPRESS_AND_VERIFY;
-   Desc.URI = "copy:" + FinalFile;
-   QueueURI(Desc);
-}
-                                                                       /*}}}*/

 // AcqIndex::Done - Finished a fetch                                   /*{{{*/
 // ---------------------------------------------------------------------
 /* This goes through a number of states.. On the initial fetch the
 // AcqIndex::Done - Finished a fetch                                   /*{{{*/
 // ---------------------------------------------------------------------
 /* This goes through a number of states.. On the initial fetch the


@@ -2634,100 +3047,92 @@ void pkgAcqIndex::Done(string const &Message,
    switch(Stage) 
    {
       case STAGE_DOWNLOAD:
    switch(Stage) 
    {
       case STAGE_DOWNLOAD:

-         StageDownloadDone(Message, Hashes, Cfg);
+         StageDownloadDone(Message);

          break;
       case STAGE_DECOMPRESS_AND_VERIFY:
          break;
       case STAGE_DECOMPRESS_AND_VERIFY:

-         StageDecompressDone(Message, Hashes, Cfg);
+         StageDecompressDone();

          break;
    }
 }
                                                                        /*}}}*/
 // AcqIndex::StageDownloadDone - Queue for decompress and verify       /*{{{*/
          break;
    }
 }
                                                                        /*}}}*/
 // AcqIndex::StageDownloadDone - Queue for decompress and verify       /*{{{*/

-void pkgAcqIndex::StageDownloadDone(string const &Message, HashStringList const &,
-                                    pkgAcquire::MethodConfig const * const)
+void pkgAcqIndex::StageDownloadDone(string const &Message)

 {
 {

+   Local = true;

    Complete = true;
 
    Complete = true;
 

-   // Handle the unzipd case
-   std::string FileName = LookupTag(Message,"Alt-Filename");
-   if (FileName.empty() == false)
+   std::string const AltFilename = LookupTag(Message,"Alt-Filename");
+   std::string Filename = LookupTag(Message,"Filename");
+
+   // we need to verify the file against the current Release file again
+   // on if-modfied-since hit to avoid a stale attack against us
+   if(StringToBool(LookupTag(Message,"IMS-Hit"),false) == true)

    {
    {

+      // copy FinalFile into partial/ so that we check the hash again
+      string const FinalFile = GetExistingFilename(GetFinalFileNameFromURI(Target.URI));
+      if (symlink(FinalFile.c_str(), DestFile.c_str()) != 0)
+        _error->WarningE("pkgAcqIndex::StageDownloadDone", "Symlinking final file %s back to %s failed", FinalFile.c_str(), DestFile.c_str());
+      else
+      {
+        EraseFileName = DestFile;
+        Filename = DestFile;
+      }

       Stage = STAGE_DECOMPRESS_AND_VERIFY;
       Stage = STAGE_DECOMPRESS_AND_VERIFY;

-      Local = true;
-      DestFile += ".decomp";
-      Desc.URI = "copy:" + FileName;
+      Desc.URI = "store:" + Filename;

       QueueURI(Desc);
       QueueURI(Desc);

-      SetActiveSubprocess("copy");
+      SetActiveSubprocess(::URI(Desc.URI).Access);

       return;
    }
       return;
    }

-   FileName = LookupTag(Message,"Filename");
-
+   // methods like file:// give us an alternative (uncompressed) file
+   else if (Target.KeepCompressed == false && AltFilename.empty() == false)
+   {
+      Filename = AltFilename;
+      EraseFileName.clear();
+   }

    // Methods like e.g. "file:" will give us a (compressed) FileName that is
    // not the "DestFile" we set, in this case we uncompress from the local file
    // Methods like e.g. "file:" will give us a (compressed) FileName that is
    // not the "DestFile" we set, in this case we uncompress from the local file

-   if (FileName != DestFile && RealFileExists(DestFile) == false)
+   else if (Filename != DestFile && RealFileExists(DestFile) == false)

    {
    {

-      Local = true;
-      if (Target.KeepCompressed == true)
+      // symlinking ensures that the filename can be used for compression detection
+      // that is e.g. needed for by-hash which has no extension over file
+      if (symlink(Filename.c_str(),DestFile.c_str()) != 0)
+        _error->WarningE("pkgAcqIndex::StageDownloadDone", "Symlinking file %s to %s failed", Filename.c_str(), DestFile.c_str());
+      else

       {
       {

-        // but if we don't keep the uncompress we copy the compressed file first
-        Stage = STAGE_DOWNLOAD;
-        Desc.URI = "copy:" + FileName;
-        QueueURI(Desc);
-        SetActiveSubprocess("copy");
-        return;
+        EraseFileName = DestFile;
+        Filename = DestFile;

       }
    }
       }
    }

-   else
-      EraseFileName = FileName;
-
-   // we need to verify the file against the current Release file again
-   // on if-modfied-since hit to avoid a stale attack against us
-   if(StringToBool(LookupTag(Message,"IMS-Hit"),false) == true)
-   {
-      // The files timestamp matches, reverify by copy into partial/
-      EraseFileName = "";
-      ReverifyAfterIMS();
-      return;
-   }

 
 

-   // get the binary name for your used compression type
-   string decompProg;
-   if(CurrentCompressionExtension == "uncompressed")
-      decompProg = "copy";
+   Stage = STAGE_DECOMPRESS_AND_VERIFY;
+   DestFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI), Target);
+   if (Filename != DestFile && flExtension(Filename) == flExtension(DestFile))
+      Desc.URI = "copy:" + Filename;

    else
    else

-      decompProg = _config->Find(string("Acquire::CompressionTypes::").append(CurrentCompressionExtension),"");
-   if(decompProg.empty() == true)
-   {
-      _error->Error("Unsupported extension: %s", CurrentCompressionExtension.c_str());
-      return;
-   }
-
-   if (Target.KeepCompressed == true)
+      Desc.URI = "store:" + Filename;
+   if (DestFile == Filename)

    {
    {

+      if (CurrentCompressionExtension == "uncompressed")
+        return StageDecompressDone();

       DestFile = "/dev/null";
       DestFile = "/dev/null";

-      EraseFileName.clear();

    }
    }

-   else
-      DestFile += ".decomp";
+
+   if (EraseFileName.empty() && Filename != AltFilename)
+      EraseFileName = Filename;

 
    // queue uri for the next stage
 
    // queue uri for the next stage

-   Stage = STAGE_DECOMPRESS_AND_VERIFY;
-   Desc.URI = decompProg + ":" + FileName;

    QueueURI(Desc);
    QueueURI(Desc);

-   SetActiveSubprocess(decompProg);
+   SetActiveSubprocess(::URI(Desc.URI).Access);

 }
                                                                        /*}}}*/
 // AcqIndex::StageDecompressDone - Final verification                  /*{{{*/
 }
                                                                        /*}}}*/
 // AcqIndex::StageDecompressDone - Final verification                  /*{{{*/

-void pkgAcqIndex::StageDecompressDone(string const &,
-                                      HashStringList const &,
-                                      pkgAcquire::MethodConfig const * const)
+void pkgAcqIndex::StageDecompressDone()

 {
 {

-   if (Target.KeepCompressed == true && DestFile == "/dev/null")
-      DestFile = GetPartialFileNameFromURI(Target.URI + '.' + CurrentCompressionExtension);
+   if (DestFile == "/dev/null")
+      DestFile = GetKeepCompressedFileName(GetPartialFileNameFromURI(Target.URI), Target);

 
    // Done, queue for rename on transaction finished
    TransactionManager->TransactionStageCopy(this, DestFile, GetFinalFilename());
 
    // Done, queue for rename on transaction finished
    TransactionManager->TransactionStageCopy(this, DestFile, GetFinalFilename());

-   return;

 }
                                                                        /*}}}*/
 pkgAcqIndex::~pkgAcqIndex() {}
 }
                                                                        /*}}}*/
 pkgAcqIndex::~pkgAcqIndex() {}


@@ -2926,9 +3331,8 @@ bool pkgAcqArchive::QueueNext()
 
       // Create the item
       Local = false;
 
       // Create the item
       Local = false;

-      QueueURI(Desc);
-

       ++Vf;
       ++Vf;

+      QueueURI(Desc);

       return true;
    }
    return false;
       return true;
    }
    return false;


@@ -3023,9 +3427,14 @@ std::string pkgAcqArchive::ShortDesc() const                             /*{{{*/
 pkgAcqArchive::~pkgAcqArchive() {}
 
 // AcqChangelog::pkgAcqChangelog - Constructors                                /*{{{*/
 pkgAcqArchive::~pkgAcqArchive() {}
 
 // AcqChangelog::pkgAcqChangelog - Constructors                                /*{{{*/

+class pkgAcqChangelog::Private
+{
+   public:
+   std::string FinalFile;
+};

 pkgAcqChangelog::pkgAcqChangelog(pkgAcquire * const Owner, pkgCache::VerIterator const &Ver,
       std::string const &DestDir, std::string const &DestFilename) :
 pkgAcqChangelog::pkgAcqChangelog(pkgAcquire * const Owner, pkgCache::VerIterator const &Ver,
       std::string const &DestDir, std::string const &DestFilename) :

-   pkgAcquire::Item(Owner), d(NULL), SrcName(Ver.SourcePkgName()), SrcVersion(Ver.SourceVerStr())
+   pkgAcquire::Item(Owner), d(new pkgAcqChangelog::Private()), SrcName(Ver.SourcePkgName()), SrcVersion(Ver.SourceVerStr())

 {
    Desc.URI = URI(Ver);
    Init(DestDir, DestFilename);
 {
    Desc.URI = URI(Ver);
    Init(DestDir, DestFilename);


@@ -3034,7 +3443,7 @@ pkgAcqChangelog::pkgAcqChangelog(pkgAcquire * const Owner, pkgCache::VerIterator
 pkgAcqChangelog::pkgAcqChangelog(pkgAcquire * const Owner, pkgCache::RlsFileIterator const &RlsFile,
       char const * const Component, char const * const SrcName, char const * const SrcVersion,
       const string &DestDir, const string &DestFilename) :
 pkgAcqChangelog::pkgAcqChangelog(pkgAcquire * const Owner, pkgCache::RlsFileIterator const &RlsFile,
       char const * const Component, char const * const SrcName, char const * const SrcVersion,
       const string &DestDir, const string &DestFilename) :

-   pkgAcquire::Item(Owner), d(NULL), SrcName(SrcName), SrcVersion(SrcVersion)
+   pkgAcquire::Item(Owner), d(new pkgAcqChangelog::Private()), SrcName(SrcName), SrcVersion(SrcVersion)

 {
    Desc.URI = URI(RlsFile, Component, SrcName, SrcVersion);
    Init(DestDir, DestFilename);
 {
    Desc.URI = URI(RlsFile, Component, SrcName, SrcVersion);
    Init(DestDir, DestFilename);


@@ -3042,7 +3451,7 @@ pkgAcqChangelog::pkgAcqChangelog(pkgAcquire * const Owner, pkgCache::RlsFileIter
 pkgAcqChangelog::pkgAcqChangelog(pkgAcquire * const Owner,
       std::string const &URI, char const * const SrcName, char const * const SrcVersion,
       const string &DestDir, const string &DestFilename) :
 pkgAcqChangelog::pkgAcqChangelog(pkgAcquire * const Owner,
       std::string const &URI, char const * const SrcName, char const * const SrcVersion,
       const string &DestDir, const string &DestFilename) :

-   pkgAcquire::Item(Owner), d(NULL), SrcName(SrcName), SrcVersion(SrcVersion)
+   pkgAcquire::Item(Owner), d(new pkgAcqChangelog::Private()), SrcName(SrcName), SrcVersion(SrcVersion)

 {
    Desc.URI = URI;
    Init(DestDir, DestFilename);
 {
    Desc.URI = URI;
    Init(DestDir, DestFilename);


@@ -3063,30 +3472,44 @@ void pkgAcqChangelog::Init(std::string const &DestDir, std::string const &DestFi
       return;
    }
 
       return;
    }
 

-   if (DestDir.empty())
+   std::string DestFileName;
+   if (DestFilename.empty())
+      DestFileName = flCombine(DestFile, SrcName + ".changelog");
+   else
+      DestFileName = flCombine(DestFile, DestFilename);
+
+   std::string const SandboxUser = _config->Find("APT::Sandbox::User");
+   std::string const systemTemp = GetTempDir(SandboxUser);
+   char tmpname[1000];
+   snprintf(tmpname, sizeof(tmpname), "%s/apt-changelog-XXXXXX", systemTemp.c_str());
+   if (NULL == mkdtemp(tmpname))
+   {
+      _error->Errno("mkdtemp", "mkdtemp failed in changelog acquire of %s %s", SrcName.c_str(), SrcVersion.c_str());
+      Status = StatError;
+      return;
+   }
+   TemporaryDirectory = tmpname;
+
+   ChangeOwnerAndPermissionOfFile("Item::QueueURI", TemporaryDirectory.c_str(),
+        SandboxUser.c_str(), ROOT_GROUP, 0700);
+
+   DestFile = flCombine(TemporaryDirectory, DestFileName);
+   if (DestDir.empty() == false)

    {
    {

-      std::string const SandboxUser = _config->Find("APT::Sandbox::User");
-      std::string const systemTemp = GetTempDir(SandboxUser);
-      char tmpname[100];
-      snprintf(tmpname, sizeof(tmpname), "%s/apt-changelog-XXXXXX", systemTemp.c_str());
-      if (NULL == mkdtemp(tmpname))
+      d->FinalFile = flCombine(DestDir, DestFileName);
+      if (RealFileExists(d->FinalFile))

       {
       {

-        _error->Errno("mkdtemp", "mkdtemp failed in changelog acquire of %s %s", SrcName.c_str(), SrcVersion.c_str());
-        Status = StatError;
-        return;
+        FileFd file1, file2;
+        if (file1.Open(DestFile, FileFd::WriteOnly | FileFd::Create | FileFd::Exclusive) &&
+              file2.Open(d->FinalFile, FileFd::ReadOnly) && CopyFile(file2, file1))
+        {
+           struct timeval times[2];
+           times[0].tv_sec = times[1].tv_sec = file2.ModificationTime();
+           times[0].tv_usec = times[1].tv_usec = 0;
+           utimes(DestFile.c_str(), times);
+        }

       }
       }

-      DestFile = TemporaryDirectory = tmpname;
-
-      ChangeOwnerAndPermissionOfFile("Item::QueueURI", DestFile.c_str(),
-                                     SandboxUser.c_str(), "root", 0700);

    }
    }

-   else
-      DestFile = DestDir;
-
-   if (DestFilename.empty())
-      DestFile = flCombine(DestFile, SrcName + ".changelog");
-   else
-      DestFile = flCombine(DestFile, DestFilename);

 
    Desc.ShortDesc = "Changelog";
    strprintf(Desc.Description, "%s %s %s Changelog", URI::SiteOnly(Desc.URI).c_str(), SrcName.c_str(), SrcVersion.c_str());
 
    Desc.ShortDesc = "Changelog";
    strprintf(Desc.Description, "%s %s %s Changelog", URI::SiteOnly(Desc.URI).c_str(), SrcName.c_str(), SrcVersion.c_str());


@@ -3096,16 +3519,48 @@ void pkgAcqChangelog::Init(std::string const &DestDir, std::string const &DestFi
                                                                        /*}}}*/
 std::string pkgAcqChangelog::URI(pkgCache::VerIterator const &Ver)     /*{{{*/
 {
                                                                        /*}}}*/
 std::string pkgAcqChangelog::URI(pkgCache::VerIterator const &Ver)     /*{{{*/
 {

+   std::string const confOnline = "Acquire::Changelogs::AlwaysOnline";
+   bool AlwaysOnline = _config->FindB(confOnline, false);
+   if (AlwaysOnline == false)
+      for (pkgCache::VerFileIterator VF = Ver.FileList(); VF.end() == false; ++VF)
+      {
+        pkgCache::PkgFileIterator const PF = VF.File();
+        if (PF.Flagged(pkgCache::Flag::NotSource) || PF->Release == 0)
+           continue;
+        pkgCache::RlsFileIterator const RF = PF.ReleaseFile();
+        if (RF->Origin != 0 && _config->FindB(confOnline + "::Origin::" + RF.Origin(), false))
+        {
+           AlwaysOnline = true;
+           break;
+        }
+      }
+   if (AlwaysOnline == false)
+   {
+      pkgCache::PkgIterator const Pkg = Ver.ParentPkg();
+      if (Pkg->CurrentVer != 0 && Pkg.CurrentVer() == Ver)
+      {
+        std::string const root = _config->FindDir("Dir");
+        std::string const basename = root + std::string("usr/share/doc/") + Pkg.Name() + "/changelog";
+        std::string const debianname = basename + ".Debian";
+        if (FileExists(debianname))
+           return "copy://" + debianname;
+        else if (FileExists(debianname + ".gz"))
+           return "gzip://" + debianname + ".gz";
+        else if (FileExists(basename))
+           return "copy://" + basename;
+        else if (FileExists(basename + ".gz"))
+           return "gzip://" + basename + ".gz";
+      }
+   }
+

    char const * const SrcName = Ver.SourcePkgName();
    char const * const SrcVersion = Ver.SourceVerStr();
    char const * const SrcName = Ver.SourcePkgName();
    char const * const SrcVersion = Ver.SourceVerStr();

-   pkgCache::PkgFileIterator PkgFile;

    // find the first source for this version which promises a changelog
    for (pkgCache::VerFileIterator VF = Ver.FileList(); VF.end() == false; ++VF)
    {
       pkgCache::PkgFileIterator const PF = VF.File();
       if (PF.Flagged(pkgCache::Flag::NotSource) || PF->Release == 0)
         continue;
    // find the first source for this version which promises a changelog
    for (pkgCache::VerFileIterator VF = Ver.FileList(); VF.end() == false; ++VF)
    {
       pkgCache::PkgFileIterator const PF = VF.File();
       if (PF.Flagged(pkgCache::Flag::NotSource) || PF->Release == 0)
         continue;

-      PkgFile = PF;

       pkgCache::RlsFileIterator const RF = PF.ReleaseFile();
       std::string const uri = URI(RF, PF.Component(), SrcName, SrcVersion);
       if (uri.empty())
       pkgCache::RlsFileIterator const RF = PF.ReleaseFile();
       std::string const uri = URI(RF, PF.Component(), SrcName, SrcVersion);
       if (uri.empty())


@@ -3148,7 +3603,7 @@ std::string pkgAcqChangelog::URITemplate(pkgCache::RlsFileIterator const &Rls)
         should be so this could produce request order-dependent anomalies */
       if (OpenMaybeClearSignedFile(Rls.FileName(), rf) == true)
       {
         should be so this could produce request order-dependent anomalies */
       if (OpenMaybeClearSignedFile(Rls.FileName(), rf) == true)
       {

-        pkgTagFile TagFile(&rf, rf.Size());
+        pkgTagFile TagFile(&rf);

         pkgTagSection Section;
         if (TagFile.Step(Section) == true)
            server = Section.FindS("Changelogs");
         pkgTagSection Section;
         if (TagFile.Step(Section) == true)
            server = Section.FindS("Changelogs");


@@ -3173,7 +3628,7 @@ std::string pkgAcqChangelog::URI(std::string const &Template,
         char const * const Component, char const * const SrcName,
         char const * const SrcVersion)
 {
         char const * const Component, char const * const SrcName,
         char const * const SrcVersion)
 {

-   if (Template.find("CHANGEPATH") == std::string::npos)
+   if (Template.find("@CHANGEPATH@") == std::string::npos)

       return "";
 
    // the path is: COMPONENT/SRC/SRCNAME/SRCNAME_SRCVER, e.g. main/a/apt/1.1 or contrib/liba/libapt/2.0
       return "";
 
    // the path is: COMPONENT/SRC/SRCNAME/SRCNAME_SRCVER, e.g. main/a/apt/1.1 or contrib/liba/libapt/2.0


@@ -3185,7 +3640,7 @@ std::string pkgAcqChangelog::URI(std::string const &Template,
    if (Component != NULL && strlen(Component) != 0)
       path = std::string(Component) + "/" + path;
 
    if (Component != NULL && strlen(Component) != 0)
       path = std::string(Component) + "/" + path;
 

-   return SubstVar(Template, "CHANGEPATH", path);
+   return SubstVar(Template, "@CHANGEPATH@", path);

 }
                                                                        /*}}}*/
 // AcqChangelog::Failed - Failure handler                              /*{{{*/
 }
                                                                        /*}}}*/
 // AcqChangelog::Failed - Failure handler                              /*{{{*/


@@ -3202,7 +3657,6 @@ void pkgAcqChangelog::Failed(string const &Message, pkgAcquire::MethodConfig con
       ErrorText = errText;
    else
       ErrorText = errText + " (" + ErrorText + ")";
       ErrorText = errText;
    else
       ErrorText = errText + " (" + ErrorText + ")";

-   return;

 }
                                                                        /*}}}*/
 // AcqChangelog::Done - Item downloaded OK                             /*{{{*/
 }
                                                                        /*}}}*/
 // AcqChangelog::Done - Item downloaded OK                             /*{{{*/


@@ -3210,6 +3664,12 @@ void pkgAcqChangelog::Done(string const &Message,HashStringList const &CalcHashe
                      pkgAcquire::MethodConfig const * const Cnf)
 {
    Item::Done(Message,CalcHashes,Cnf);
                      pkgAcquire::MethodConfig const * const Cnf)
 {
    Item::Done(Message,CalcHashes,Cnf);

+   if (d->FinalFile.empty() == false)
+   {
+      if (RemoveFile("pkgAcqChangelog::Done", d->FinalFile) == false ||
+           Rename(DestFile, d->FinalFile) == false)
+        Status = StatError;
+   }

 
    Complete = true;
 }
 
    Complete = true;
 }


@@ -3221,6 +3681,7 @@ pkgAcqChangelog::~pkgAcqChangelog()                                       /*{{{*/
       RemoveFile("~pkgAcqChangelog", DestFile);
       rmdir(TemporaryDirectory.c_str());
    }
       RemoveFile("~pkgAcqChangelog", DestFile);
       rmdir(TemporaryDirectory.c_str());
    }

+   delete d;

 }
                                                                        /*}}}*/
 
 }
                                                                        /*}}}*/