]> git.saurik.com Git - apt.git/blobdiff - apt-pkg/acquire-item.cc
Wreck validation until we can assess ecosystem :/.
[apt.git] / apt-pkg / acquire-item.cc
index 208b84c64cb95ac4b198a212ef46596b810a7680..663452b9f1c92451c72ac5008f46e4c0c83411f4 100644 (file)
@@ -46,6 +46,7 @@
 #include <ctime>
 #include <sstream>
 #include <numeric>
+#include <random>
 
 #include <apti18n.h>
                                                                        /*}}}*/
@@ -145,7 +146,7 @@ static void ReportMirrorFailureToCentral(pkgAcquire::Item const &I, std::string
             << FailCode << std::endl;
 #endif
    string const report = _config->Find("Methods::Mirror::ProblemReporting",
-                                "/usr/lib/apt/apt-report-mirror-failure");
+                                LIBEXEC_DIR "/apt-report-mirror-failure");
    if(!FileExists(report))
       return;
 
@@ -265,7 +266,7 @@ static bool APT_NONNULL(3, 4, 5) AllowInsecureRepositories(InsecureType const ms
 
    if (TargetIsAllowedToBe(TransactionManager->Target, msg) == true)
    {
-      MessageInsecureRepository(false, msgstr, repo);
+      //MessageInsecureRepository(false, msgstr, repo);
       return true;
    }
 
@@ -410,7 +411,7 @@ bool pkgAcqTransactionItem::QueueURI(pkgAcquire::ItemDesc &Item)
       return false;
    }
    // If we got the InRelease file via a mirror, pick all indexes directly from this mirror, too
-   if (TransactionManager->BaseURI.empty() == false &&
+   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
@@ -451,7 +452,11 @@ std::string pkgAcquire::Item::GetFinalFilename() const
 }
 std::string pkgAcqDiffIndex::GetFinalFilename() const
 {
-   return GetFinalFileNameFromURI(GetDiffIndexURI(Target));
+   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
 {
@@ -488,7 +493,10 @@ std::string pkgAcqIndex::GetMetaKey() const
 }
 std::string pkgAcqDiffIndex::GetMetaKey() const
 {
-   return GetDiffIndexFileName(Target.MetaKey);
+   auto const metakey = GetDiffIndexFileName(Target.MetaKey);
+   if (CurrentCompressionExtension == "uncompressed")
+      return metakey;
+   return metakey + "." + CurrentCompressionExtension;
 }
                                                                        /*}}}*/
 //pkgAcqTransactionItem::TransactionState and specialisations for child classes        /*{{{*/
@@ -685,10 +693,15 @@ class APT_HIDDEN CleanupItem : public pkgAcqTransactionItem               /*{{{*/
                                                                        /*}}}*/
 
 // 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),
-    QueueCounter(0), ExpectedAdditionalItems(0), Owner(owner), d(NULL)
+    QueueCounter(0), ExpectedAdditionalItems(0), Owner(owner), d(new Private())
 {
    Owner->Add(this);
    Status = StatIdle;
@@ -699,6 +712,7 @@ APT_IGNORE_DEPRECATED_POP
 pkgAcquire::Item::~Item()
 {
    Owner->Remove(this);
+   delete d;
 }
                                                                        /*}}}*/
 std::string pkgAcquire::Item::Custom600Headers() const                 /*{{{*/
@@ -734,6 +748,18 @@ APT_CONST bool pkgAcquire::Item::IsTrusted() const                 /*{{{*/
 // ---------------------------------------------------------------------
 /* 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)
 {
    if (QueueCounter <= 1)
@@ -766,43 +792,46 @@ void pkgAcquire::Item::Failed(string const &Message,pkgAcquire::MethodConfig con
    }
 
    string const FailReason = LookupTag(Message, "FailReason");
-   enum { MAXIMUM_SIZE_EXCEEDED, HASHSUM_MISMATCH, WEAK_HASHSUMS, OTHER } failreason = OTHER;
+   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)
       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)
       {
-        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 MAXIMUM_SIZE_EXCEEDED:
-           case OTHER:
-              out << LookupTag(Message, "Message") << std::endl;
-              break;
-        }
         auto const ExpectedHashes = GetExpectedHashes();
         if (ExpectedHashes.empty() == false)
         {
            out << "Hashes of expected file:" << std::endl;
            for (auto const &hs: ExpectedHashes)
-           {
-              out << " - " << hs.toStr();
-              if (hs.usable() == false)
-                 out << " [weak]";
-              out << std::endl;
-           }
+              formatHashsum(out, hs);
         }
         if (failreason == HASHSUM_MISMATCH)
         {
@@ -812,20 +841,14 @@ void pkgAcquire::Item::Failed(string const &Message,pkgAcquire::MethodConfig con
               std::string const tagname = std::string(*type) + "-Hash";
               std::string const hashsum = LookupTag(Message, tagname.c_str());
               if (hashsum.empty() == false)
-              {
-                 auto const hs = HashString(*type, hashsum);
-                 out << " - " << hs.toStr();
-                 if (hs.usable() == false)
-                    out << " [weak]";
-                 out << std::endl;
-              }
+                 formatHashsum(out, HashString(*type, hashsum));
            }
-           out << "Last modification reported: " << LookupTag(Message, "Last-Modified", "<none>") << std::endl;
         }
-        ErrorText = out.str();
+        auto const lastmod = LookupTag(Message, "Last-Modified", "");
+        if (lastmod.empty() == false)
+           out << "Last modification reported: " << lastmod << std::endl;
       }
-      else
-        ErrorText = LookupTag(Message,"Message");
+      ErrorText = out.str();
    }
 
    switch (failreason)
@@ -833,6 +856,7 @@ void pkgAcquire::Item::Failed(string const &Message,pkgAcquire::MethodConfig con
       case MAXIMUM_SIZE_EXCEEDED: RenameOnError(MaximumSizeExceeded); break;
       case HASHSUM_MISMATCH: RenameOnError(HashSumMismatch); break;
       case WEAK_HASHSUMS: break;
+      case REDIRECTION_LOOP: break;
       case OTHER: break;
    }
 
@@ -976,6 +1000,47 @@ std::string pkgAcquire::Item::HashSum() const                             /*{{{*/
    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) :
@@ -1192,9 +1257,15 @@ bool pkgAcqMetaBase::CheckDownloadDone(pkgAcqTransactionItem * const I, const st
    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");
@@ -1293,6 +1364,23 @@ void pkgAcqMetaClearSig::QueueIndexes(bool const verify)                 /*{{{*/
    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
@@ -1471,24 +1559,6 @@ void pkgAcqMetaClearSig::QueueIndexes(bool const verify)                 /*{{{*/
                                                                        /*}}}*/
 bool pkgAcqMetaBase::VerifyVendor(string const &)                      /*{{{*/
 {
-   string Transformed = TransactionManager->MetaIndexParser->GetExpectedDist();
-
-   if (Transformed == "../project/experimental")
-   {
-      Transformed = "experimental";
-   }
-
-   auto 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();
@@ -1523,30 +1593,27 @@ bool pkgAcqMetaBase::VerifyVendor(string const &)                       /*{{{*/
       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 Suite: " << TransactionManager->MetaIndexParser->GetSuite() << 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;
 }
                                                                        /*}}}*/
@@ -1838,10 +1905,16 @@ void pkgAcqMetaSig::Done(string const &Message, HashStringList const &Hashes,
    }
    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)
@@ -1931,51 +2004,52 @@ pkgAcqBaseIndex::~pkgAcqBaseIndex() {}
 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);
 
-   Desc.Owner = this;
-   Desc.Description = GetDiffIndexFileName(Target.Description);
-   Desc.ShortDesc = Target.ShortDesc;
-   Desc.URI = GetDiffIndexURI(Target);
-
-   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;
-
-   QueueURI(Desc);
-}
-                                                                       /*}}}*/
-// AcqIndex::Custom600Headers - Insert custom request headers          /*{{{*/
-// ---------------------------------------------------------------------
-/* The only header we use is the last-modified header. */
-string pkgAcqDiffIndex::Custom600Headers() const
-{
-   if (TransactionManager->LastMetaIndexParser != NULL)
-      return "\nIndex-File: true";
-
-   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, false);
 }
                                                                        /*}}}*/
 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)      /*{{{*/
@@ -1987,7 +2061,7 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile) /*{{{*/
       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;
@@ -1999,7 +2073,7 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile) /*{{{*/
    HashStringList ServerHashes;
    unsigned long long ServerSize = 0;
 
-   auto const &posix = std::locale("C.UTF-8");
+   auto const &posix = std::locale::classic();
    for (char const * const * type = HashString::SupportedHashes(); *type != NULL; ++type)
    {
       std::string tagname = *type;
@@ -2318,23 +2392,15 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile)       /*{{{*/
       if (unlikely(Final.empty())) // because we wouldn't be called in such a case
         return false;
       std::string const PartialFile = GetPartialFileNameFromURI(Target.URI);
-      if (FileExists(PartialFile) && RemoveFile("Bootstrap-linking", PartialFile) == false)
-      {
-        if (Debug)
-           std::clog << "Bootstrap-linking for patching " << CurrentPackagesFile
-              << " by removing stale " << PartialFile << " failed!" << std::endl;
+      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())
       {
-        std::string const Partial = PartialFile + ext;
-        if (FileExists(Partial) && RemoveFile("Bootstrap-linking", Partial) == false)
-        {
-           if (Debug)
-              std::clog << "Bootstrap-linking for patching " << CurrentPackagesFile
-                 << " by removing stale " << Partial << " failed!" << std::endl;
+        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;
@@ -2347,14 +2413,26 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile)       /*{{{*/
       }
    }
 
+   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)
-      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,
-               Target,
+               Target, UsedMirror, indexURI,
               available_patches[i],
               diffs);
    }
@@ -2367,7 +2445,9 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string const &IndexDiffFile) /*{{{*/
                                                                        /*}}}*/
 void pkgAcqDiffIndex::Failed(string const &Message,pkgAcquire::MethodConfig const * const Cnf)/*{{{*/
 {
-   pkgAcqBaseIndex::Failed(Message,Cnf);
+   if (CommonFailed(GetDiffIndexURI(Target), GetDiffIndexFileName(Target.Description), Message, Cnf))
+      return;
+
    Status = StatDone;
    ExpectedAdditionalItems = 0;
 
@@ -2422,8 +2502,9 @@ pkgAcqDiffIndex::~pkgAcqDiffIndex()
 pkgAcqIndexDiffs::pkgAcqIndexDiffs(pkgAcquire * const Owner,
                                    pkgAcqMetaClearSig * const TransactionManager,
                                    IndexTarget const &Target,
+                                  std::string const &indexUsedMirror, std::string const &indexURI,
                                   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);
@@ -2434,6 +2515,12 @@ pkgAcqIndexDiffs::pkgAcqIndexDiffs(pkgAcquire * const Owner,
    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
@@ -2548,7 +2635,7 @@ bool pkgAcqIndexDiffs::QueueNextDiff()                                    /*{{{*/
    }
 
    // 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);
 
@@ -2601,7 +2688,7 @@ void pkgAcqIndexDiffs::Done(string const &Message, HashStringList const &Hashes,
         // see if there is more to download
         if(available_patches.empty() == false)
         {
-           new pkgAcqIndexDiffs(Owner, TransactionManager, Target, available_patches);
+           new pkgAcqIndexDiffs(Owner, TransactionManager, Target, UsedMirror, indexURI, available_patches);
            Finish();
         } else {
            DestFile = PatchedFile;
@@ -2616,9 +2703,10 @@ std::string pkgAcqIndexDiffs::Custom600Headers() const                   /*{{{*/
    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();
 }
@@ -2629,19 +2717,26 @@ pkgAcqIndexDiffs::~pkgAcqIndexDiffs() {}
 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)
-  : 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);
 
-   Desc.Owner = this;
    Description = Target.Description;
+   UsedMirror = indexUsedMirror;
+   if (UsedMirror == "DIRECT")
+      UsedMirror.clear();
+   else if (UsedMirror.empty() == false && Description.find(" ") != string::npos)
+      Description.replace(0, Description.find(" "), UsedMirror);
+
+   Desc.Owner = this;
    Desc.ShortDesc = Target.ShortDesc;
-   Desc.URI = Target.URI + ".diff/" + patch.file + ".gz";
+   Desc.URI = indexURI + ".diff/" + patch.file + ".gz";
    Desc.Description = Description + " " + patch.file + ".pdiff";
-   DestFile = GetPartialFileNameFromURI(Desc.URI);
+   DestFile = GetPartialFileNameFromURI(Target.URI + ".diff/" + patch.file + ".gz");
 
    if(Debug)
       std::clog << "pkgAcqIndexMergeDiffs: " << Desc.URI << std::endl;
@@ -2765,12 +2860,14 @@ std::string pkgAcqIndexMergeDiffs::Custom600Headers() const             /*{{{*/
       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)
-        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();
@@ -2782,10 +2879,12 @@ pkgAcqIndexMergeDiffs::~pkgAcqIndexMergeDiffs() {}
 // 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))
 {
+   if (Derived)
+      return;
    Init(Target.URI, Target.Description, Target.ShortDesc);
 
    if(_config->FindB("Debug::Acquire::Transaction", false) == true)
@@ -2818,10 +2917,6 @@ void pkgAcqIndex::Init(string const &URI, string const &URIDesc,
    DestFile = GetPartialFileNameFromURI(URI);
    NextCompressionExtension(CurrentCompressionExtension, CompressionExtensions, false);
 
-   // store file size of the download to ensure the fetcher gives
-   // accurate progress reporting
-   FileSize = GetExpectedHashes().FileSize();
-
    if (CurrentCompressionExtension == "uncompressed")
    {
       Desc.URI = URI;
@@ -2836,6 +2931,8 @@ void pkgAcqIndex::Init(string const &URI, string const &URIDesc,
         Desc.URI = URI + '.' + CurrentCompressionExtension;
         DestFile = DestFile + '.' + CurrentCompressionExtension;
       }
+      else
+        Desc.URI = URI;
 
       HashStringList const Hashes = GetExpectedHashes();
       HashString const * const TargetHash = Hashes.find(NULL);
@@ -2858,6 +2955,9 @@ void pkgAcqIndex::Init(string const &URI, string const &URIDesc,
       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;
@@ -2890,20 +2990,40 @@ string pkgAcqIndex::Custom600Headers() const
 }
                                                                        /*}}}*/
 // 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)
 {
    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)
       {
-        Init(Target.URI, Desc.Description, Desc.ShortDesc);
+        Init(TargetURI, Desc.Description, Desc.ShortDesc);
         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;
@@ -3211,9 +3331,8 @@ bool pkgAcqArchive::QueueNext()
 
       // Create the item
       Local = false;
-      QueueURI(Desc);
-
       ++Vf;
+      QueueURI(Desc);
       return true;
    }
    return false;
@@ -3372,7 +3491,7 @@ void pkgAcqChangelog::Init(std::string const &DestDir, std::string const &DestFi
    TemporaryDirectory = tmpname;
 
    ChangeOwnerAndPermissionOfFile("Item::QueueURI", TemporaryDirectory.c_str(),
-        SandboxUser.c_str(), "root", 0700);
+        SandboxUser.c_str(), ROOT_GROUP, 0700);
 
    DestFile = flCombine(TemporaryDirectory, DestFileName);
    if (DestDir.empty() == false)
@@ -3420,7 +3539,8 @@ std::string pkgAcqChangelog::URI(pkgCache::VerIterator const &Ver)        /*{{{*/
       pkgCache::PkgIterator const Pkg = Ver.ParentPkg();
       if (Pkg->CurrentVer != 0 && Pkg.CurrentVer() == Ver)
       {
-        std::string const basename = std::string("/usr/share/doc/") + Pkg.Name() + "/changelog";
+        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;
@@ -3483,7 +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)
       {
-        pkgTagFile TagFile(&rf, rf.Size());
+        pkgTagFile TagFile(&rf);
         pkgTagSection Section;
         if (TagFile.Step(Section) == true)
            server = Section.FindS("Changelogs");