]> git.saurik.com Git - apt.git/blobdiff - apt-pkg/acquire-item.cc
* apt-pkg/policy.cc:
[apt.git] / apt-pkg / acquire-item.cc
index a6d01e3bb01cdd0a98f7c64b1667e3f95a5b9e16..4f0abbb91ddb6b9b95015a0aecdd3e3d2bae9468 100644 (file)
@@ -15,6 +15,7 @@
 // Include Files                                                       /*{{{*/
 #include <apt-pkg/acquire-item.h>
 #include <apt-pkg/configuration.h>
 // Include Files                                                       /*{{{*/
 #include <apt-pkg/acquire-item.h>
 #include <apt-pkg/configuration.h>
+#include <apt-pkg/aptconfiguration.h>
 #include <apt-pkg/sourcelist.h>
 #include <apt-pkg/vendorlist.h>
 #include <apt-pkg/error.h>
 #include <apt-pkg/sourcelist.h>
 #include <apt-pkg/vendorlist.h>
 #include <apt-pkg/error.h>
@@ -131,9 +132,7 @@ void pkgAcquire::Item::Rename(string From,string To)
    }   
 }
                                                                        /*}}}*/
    }   
 }
                                                                        /*}}}*/
-
-
-// AcqDiffIndex::AcqDiffIndex - Constructor                    
+// AcqDiffIndex::AcqDiffIndex - Constructor                            /*{{{*/
 // ---------------------------------------------------------------------
 /* Get the DiffIndex file first and see if there are patches availabe 
  * If so, create a pkgAcqIndexDiffs fetcher that will get and apply the
 // ---------------------------------------------------------------------
 /* Get the DiffIndex file first and see if there are patches availabe 
  * If so, create a pkgAcqIndexDiffs fetcher that will get and apply the
@@ -184,7 +183,7 @@ pkgAcqDiffIndex::pkgAcqDiffIndex(pkgAcquire *Owner,
    QueueURI(Desc);
 
 }
    QueueURI(Desc);
 
 }
-
+                                                                       /*}}}*/
 // AcqIndex::Custom600Headers - Insert custom request headers          /*{{{*/
 // ---------------------------------------------------------------------
 /* The only header we use is the last-modified header. */
 // AcqIndex::Custom600Headers - Insert custom request headers          /*{{{*/
 // ---------------------------------------------------------------------
 /* The only header we use is the last-modified header. */
@@ -202,9 +201,8 @@ string pkgAcqDiffIndex::Custom600Headers()
    
    return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
 }
    
    return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
 }
-
-
-bool pkgAcqDiffIndex::ParseDiffIndex(string IndexDiffFile)
+                                                                       /*}}}*/
+bool pkgAcqDiffIndex::ParseDiffIndex(string IndexDiffFile)             /*{{{*/
 {
    if(Debug)
       std::clog << "pkgAcqIndexDiffs::ParseIndexDiff() " << IndexDiffFile 
 {
    if(Debug)
       std::clog << "pkgAcqIndexDiffs::ParseIndexDiff() " << IndexDiffFile 
@@ -221,19 +219,19 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string IndexDiffFile)
 
    if(TF.Step(Tags) == true)
    {
 
    if(TF.Step(Tags) == true)
    {
-      string local_sha1;
       bool found = false;
       DiffInfo d;
       string size;
 
       bool found = false;
       DiffInfo d;
       string size;
 
-      string tmp = Tags.FindS("SHA1-Current");
+      string const tmp = Tags.FindS("SHA1-Current");
       std::stringstream ss(tmp);
       std::stringstream ss(tmp);
-      ss >> ServerSha1;
+      ss >> ServerSha1 >> size;
+      unsigned long const ServerSize = atol(size.c_str());
 
       FileFd fd(CurrentPackagesFile, FileFd::ReadOnly);
       SHA1Summation SHA1;
       SHA1.AddFD(fd.Fd(), fd.Size());
 
       FileFd fd(CurrentPackagesFile, FileFd::ReadOnly);
       SHA1Summation SHA1;
       SHA1.AddFD(fd.Fd(), fd.Size());
-      local_sha1 = string(SHA1.Result());
+      string const local_sha1 = SHA1.Result();
 
       if(local_sha1 == ServerSha1) 
       {
 
       if(local_sha1 == ServerSha1) 
       {
@@ -250,20 +248,56 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string IndexDiffFile)
            std::clog << "SHA1-Current: " << ServerSha1 << std::endl;
 
         // check the historie and see what patches we need
            std::clog << "SHA1-Current: " << ServerSha1 << std::endl;
 
         // check the historie and see what patches we need
-        string history = Tags.FindS("SHA1-History");     
+        string const history = Tags.FindS("SHA1-History");
         std::stringstream hist(history);
         std::stringstream hist(history);
-        while(hist >> d.sha1 >> size >> d.file) 
+        while(hist >> d.sha1 >> size >> d.file)
         {
         {
-           d.size = atoi(size.c_str());
            // read until the first match is found
            // read until the first match is found
+           // from that point on, we probably need all diffs
            if(d.sha1 == local_sha1) 
               found=true;
            if(d.sha1 == local_sha1) 
               found=true;
-           // from that point on, we probably need all diffs
-           if(found) 
+           else if (found == false)
+              continue;
+
+           if(Debug)
+              std::clog << "Need to get diff: " << d.file << std::endl;
+           available_patches.push_back(d);
+        }
+
+        if (available_patches.empty() == 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())
+           {
+              if (Debug)
+                 std::clog << "Need " << available_patches.size() << " diffs (Limit is " << fileLimit
+                       << ") so fallback to complete download" << std::endl;
+              return false;
+           }
+
+           // see if the patches are too big
+           found = false; // it was true and it will be true again at the end
+           d = *available_patches.begin();
+           string const firstPatch = d.file;
+           unsigned long patchesSize = 0;
+           std::stringstream patches(Tags.FindS("SHA1-Patches"));
+           while(patches >> d.sha1 >> size >> d.file)
+           {
+              if (firstPatch == d.file)
+                 found = true;
+              else if (found == false)
+                 continue;
+
+              patchesSize += atol(size.c_str());
+           }
+           unsigned long const sizeLimit = ServerSize * _config->FindI("Acquire::PDiffs::SizeLimit", 100);
+           if (sizeLimit > 0 && (sizeLimit/100) < patchesSize)
            {
            {
-              if(Debug)
-                 std::clog << "Need to get diff: " << d.file << std::endl;
-              available_patches.push_back(d);
+              if (Debug)
+                 std::clog << "Need " << patchesSize << " bytes (Limit is " << sizeLimit/100
+                       << ") so fallback to complete download" << std::endl;
+              return false;
            }
         }
       }
            }
         }
       }
@@ -272,11 +306,11 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string IndexDiffFile)
       if(found) 
       {
         // queue the diffs
       if(found) 
       {
         // queue the diffs
-        string::size_type last_space = Description.rfind(" ");
+        string::size_type const last_space = Description.rfind(" ");
         if(last_space != string::npos)
            Description.erase(last_space, Description.size()-last_space);
         new pkgAcqIndexDiffs(Owner, RealURI, Description, Desc.ShortDesc,
         if(last_space != string::npos)
            Description.erase(last_space, Description.size()-last_space);
         new pkgAcqIndexDiffs(Owner, RealURI, Description, Desc.ShortDesc,
-                             ExpectedHash, available_patches);
+                             ExpectedHash, ServerSha1, available_patches);
         Complete = false;
         Status = StatDone;
         Dequeue();
         Complete = false;
         Status = StatDone;
         Dequeue();
@@ -291,8 +325,8 @@ bool pkgAcqDiffIndex::ParseDiffIndex(string IndexDiffFile)
       std::clog << "Can't find a patch in the index file" << std::endl;
    return false;
 }
       std::clog << "Can't find a patch in the index file" << std::endl;
    return false;
 }
-
-void pkgAcqDiffIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
+                                                                       /*}}}*/
+void pkgAcqDiffIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)     /*{{{*/
 {
    if(Debug)
       std::clog << "pkgAcqDiffIndex failed: " << Desc.URI << std::endl
 {
    if(Debug)
       std::clog << "pkgAcqDiffIndex failed: " << Desc.URI << std::endl
@@ -305,8 +339,8 @@ void pkgAcqDiffIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
    Status = StatDone;
    Dequeue();
 }
    Status = StatDone;
    Dequeue();
 }
-
-void pkgAcqDiffIndex::Done(string Message,unsigned long Size,string Md5Hash,
+                                                                       /*}}}*/
+void pkgAcqDiffIndex::Done(string Message,unsigned long Size,string Md5Hash,   /*{{{*/
                           pkgAcquire::MethodConfig *Cnf)
 {
    if(Debug)
                           pkgAcquire::MethodConfig *Cnf)
 {
    if(Debug)
@@ -335,10 +369,8 @@ void pkgAcqDiffIndex::Done(string Message,unsigned long Size,string Md5Hash,
    Dequeue();
    return;
 }
    Dequeue();
    return;
 }
-
-
-
-// AcqIndexDiffs::AcqIndexDiffs - Constructor                  
+                                                                       /*}}}*/
+// AcqIndexDiffs::AcqIndexDiffs - Constructor                          /*{{{*/
 // ---------------------------------------------------------------------
 /* The package diff is added to the queue. one object is constructed
  * for each diff and the index
 // ---------------------------------------------------------------------
 /* The package diff is added to the queue. one object is constructed
  * for each diff and the index
@@ -346,9 +378,10 @@ void pkgAcqDiffIndex::Done(string Message,unsigned long Size,string Md5Hash,
 pkgAcqIndexDiffs::pkgAcqIndexDiffs(pkgAcquire *Owner,
                                   string URI,string URIDesc,string ShortDesc,
                                   HashString ExpectedHash, 
 pkgAcqIndexDiffs::pkgAcqIndexDiffs(pkgAcquire *Owner,
                                   string URI,string URIDesc,string ShortDesc,
                                   HashString ExpectedHash, 
+                                  string ServerSha1,
                                   vector<DiffInfo> diffs)
    : Item(Owner), RealURI(URI), ExpectedHash(ExpectedHash), 
                                   vector<DiffInfo> diffs)
    : Item(Owner), RealURI(URI), ExpectedHash(ExpectedHash), 
-     available_patches(diffs)
+     available_patches(diffs), ServerSha1(ServerSha1)
 {
    
    DestFile = _config->FindDir("Dir::State::lists") + "partial/";
 {
    
    DestFile = _config->FindDir("Dir::State::lists") + "partial/";
@@ -372,9 +405,8 @@ pkgAcqIndexDiffs::pkgAcqIndexDiffs(pkgAcquire *Owner,
       QueueNextDiff();
    }
 }
       QueueNextDiff();
    }
 }
-
-
-void pkgAcqIndexDiffs::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
+                                                                       /*}}}*/
+void pkgAcqIndexDiffs::Failed(string Message,pkgAcquire::MethodConfig *Cnf)    /*{{{*/
 {
    if(Debug)
       std::clog << "pkgAcqIndexDiffs failed: " << Desc.URI << std::endl
 {
    if(Debug)
       std::clog << "pkgAcqIndexDiffs failed: " << Desc.URI << std::endl
@@ -383,9 +415,8 @@ void pkgAcqIndexDiffs::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
                   ExpectedHash);
    Finish();
 }
                   ExpectedHash);
    Finish();
 }
-
-
-// helper that cleans the item out of the fetcher queue
+                                                                       /*}}}*/
+// Finish - helper that cleans the item out of the fetcher queue       /*{{{*/
 void pkgAcqIndexDiffs::Finish(bool allDone)
 {
    // we restore the original name, this is required, otherwise
 void pkgAcqIndexDiffs::Finish(bool allDone)
 {
    // we restore the original name, this is required, otherwise
@@ -420,10 +451,8 @@ void pkgAcqIndexDiffs::Finish(bool allDone)
    Dequeue();
    return;
 }
    Dequeue();
    return;
 }
-
-
-
-bool pkgAcqIndexDiffs::QueueNextDiff()
+                                                                       /*}}}*/
+bool pkgAcqIndexDiffs::QueueNextDiff()                                 /*{{{*/
 {
 
    // calc sha1 of the just patched file
 {
 
    // calc sha1 of the just patched file
@@ -438,6 +467,13 @@ bool pkgAcqIndexDiffs::QueueNextDiff()
       std::clog << "QueueNextDiff: " 
                << FinalFile << " (" << local_sha1 << ")"<<std::endl;
 
       std::clog << "QueueNextDiff: " 
                << FinalFile << " (" << local_sha1 << ")"<<std::endl;
 
+   // final file reached before all patches are applied
+   if(local_sha1 == ServerSha1)
+   {
+      Finish(true);
+      return true;
+   }
+
    // 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();
    // 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();
@@ -469,10 +505,8 @@ bool pkgAcqIndexDiffs::QueueNextDiff()
 
    return true;
 }
 
    return true;
 }
-
-
-
-void pkgAcqIndexDiffs::Done(string Message,unsigned long Size,string Md5Hash,
+                                                                       /*}}}*/
+void pkgAcqIndexDiffs::Done(string Message,unsigned long Size,string Md5Hash,  /*{{{*/
                            pkgAcquire::MethodConfig *Cnf)
 {
    if(Debug)
                            pkgAcquire::MethodConfig *Cnf)
 {
    if(Debug)
@@ -537,14 +571,13 @@ void pkgAcqIndexDiffs::Done(string Message,unsigned long Size,string Md5Hash,
       // see if there is more to download
       if(available_patches.size() > 0) {
         new pkgAcqIndexDiffs(Owner, RealURI, Description, Desc.ShortDesc,
       // see if there is more to download
       if(available_patches.size() > 0) {
         new pkgAcqIndexDiffs(Owner, RealURI, Description, Desc.ShortDesc,
-                             ExpectedHash, available_patches);
+                             ExpectedHash, ServerSha1, available_patches);
         return Finish();
       } else 
         return Finish(true);
    }
 }
         return Finish();
       } else 
         return Finish(true);
    }
 }
-
-
+                                                                       /*}}}*/
 // AcqIndex::AcqIndex - Constructor                                    /*{{{*/
 // ---------------------------------------------------------------------
 /* The package file is added to the queue and a second class is 
 // AcqIndex::AcqIndex - Constructor                                    /*{{{*/
 // ---------------------------------------------------------------------
 /* The package file is added to the queue and a second class is 
@@ -563,14 +596,15 @@ pkgAcqIndex::pkgAcqIndex(pkgAcquire *Owner,
    if(comprExt.empty()) 
    {
       // autoselect the compression method
    if(comprExt.empty()) 
    {
       // autoselect the compression method
-      if(FileExists("/bin/bzip2")) 
-        CompressionExtension = ".bz2";
-      else 
-        CompressionExtension = ".gz";
-   } else {
-      CompressionExtension = comprExt;
+      std::vector<std::string> types = APT::Configuration::getCompressionTypes();
+      if (types.empty() == true)
+        comprExt = "plain";
+      else
+        comprExt = "." + types[0];
    }
    }
-   Desc.URI = URI + CompressionExtension; 
+   CompressionExtension = ((comprExt == "plain" || comprExt == ".") ? "" : comprExt);
+
+   Desc.URI = URI + CompressionExtension;
 
    Desc.Description = URIDesc;
    Desc.Owner = this;
 
    Desc.Description = URIDesc;
    Desc.Owner = this;
@@ -594,22 +628,35 @@ string pkgAcqIndex::Custom600Headers()
    return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
 }
                                                                        /*}}}*/
    return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
 }
                                                                        /*}}}*/
-
-void pkgAcqIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
+void pkgAcqIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf) /*{{{*/
 {
 {
-   // no .bz2 found, retry with .gz
-   if(Desc.URI.substr(Desc.URI.size()-3) == "bz2") {
-      Desc.URI = Desc.URI.substr(0,Desc.URI.size()-3) + "gz"; 
+   std::vector<std::string> types = APT::Configuration::getCompressionTypes();
 
 
-      // retry with a gzip one 
-      new pkgAcqIndex(Owner, RealURI, Desc.Description,Desc.ShortDesc, 
-                     ExpectedHash, string(".gz"));
+   for (std::vector<std::string>::const_iterator t = types.begin();
+       t != types.end(); t++)
+   {
+      // jump over all already tried compression types
+      const unsigned int nameLen = Desc.URI.size() - (*t).size();
+      if(Desc.URI.substr(nameLen) != *t)
+        continue;
+
+      // we want to try it with the next extension (and make sure to 
+      // not skip over the end)
+      t++;
+      if (t == types.end())
+        break;
+
+      // queue new download
+      Desc.URI = Desc.URI.substr(0, nameLen) + *t;
+      new pkgAcqIndex(Owner, RealURI, Desc.Description, Desc.ShortDesc,
+      ExpectedHash, string(".").append(*t));
+      
       Status = StatDone;
       Complete = false;
       Dequeue();
       return;
       Status = StatDone;
       Complete = false;
       Dequeue();
       return;
-   } 
-   
+   }
+
    // on decompression failure, remove bad versions in partial/
    if(Decompression && Erase) {
       string s = _config->FindDir("Dir::State::lists") + "partial/";
    // on decompression failure, remove bad versions in partial/
    if(Decompression && Erase) {
       string s = _config->FindDir("Dir::State::lists") + "partial/";
@@ -619,8 +666,7 @@ void pkgAcqIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
 
    Item::Failed(Message,Cnf);
 }
 
    Item::Failed(Message,Cnf);
 }
-
-
+                                                                       /*}}}*/
 // 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
@@ -693,22 +739,26 @@ void pkgAcqIndex::Done(string Message,unsigned long Size,string Hash,
    
    // The files timestamp matches
    if (StringToBool(LookupTag(Message,"IMS-Hit"),false) == true)
    
    // The files timestamp matches
    if (StringToBool(LookupTag(Message,"IMS-Hit"),false) == true)
-   {
-      unlink(FileName.c_str());
       return;
       return;
-   }
 
    if (FileName == DestFile)
       Erase = true;
    else
       Local = true;
    
 
    if (FileName == DestFile)
       Erase = true;
    else
       Local = true;
    
-   string compExt = Desc.URI.substr(Desc.URI.size()-3);
-   char *decompProg;
-   if(compExt == "bz2") 
-      decompProg = "bzip2";
-   else if(compExt == ".gz") 
-      decompProg = "gzip";
+   string compExt = flExtension(flNotDir(URI(Desc.URI).Path));
+   string decompProg;
+
+   // get the binary name for your used compression type
+   decompProg = _config->Find(string("Acquire::CompressionTypes::").append(compExt),"");
+   if(decompProg.empty() == false);
+   // flExtensions returns the full name if no extension is found
+   // this is why we have this complicated compare operation here
+   // FIMXE: add a new flJustExtension() that return "" if no
+   //        extension is found and use that above so that it can
+   //        be tested against ""
+   else if(compExt == flNotDir(URI(Desc.URI).Path))
+      decompProg = "copy";
    else {
       _error->Error("Unsupported extension: %s", compExt.c_str());
       return;
    else {
       _error->Error("Unsupported extension: %s", compExt.c_str());
       return;
@@ -716,11 +766,11 @@ void pkgAcqIndex::Done(string Message,unsigned long Size,string Hash,
 
    Decompression = true;
    DestFile += ".decomp";
 
    Decompression = true;
    DestFile += ".decomp";
-   Desc.URI = string(decompProg) + ":" + FileName;
+   Desc.URI = decompProg + ":" + FileName;
    QueueURI(Desc);
    QueueURI(Desc);
-   Mode = decompProg;
+   Mode = decompProg.c_str();
 }
 }
-
+                                                                       /*}}}*/
 // AcqIndexTrans::pkgAcqIndexTrans - Constructor                       /*{{{*/
 // ---------------------------------------------------------------------
 /* The Translation file is added to the queue */
 // AcqIndexTrans::pkgAcqIndexTrans - Constructor                       /*{{{*/
 // ---------------------------------------------------------------------
 /* The Translation file is added to the queue */
@@ -729,7 +779,6 @@ pkgAcqIndexTrans::pkgAcqIndexTrans(pkgAcquire *Owner,
   : pkgAcqIndex(Owner, URI, URIDesc, ShortDesc, HashString(), "")
 {
 }
   : pkgAcqIndex(Owner, URI, URIDesc, ShortDesc, HashString(), "")
 {
 }
-
                                                                        /*}}}*/
 // AcqIndexTrans::Failed - Silence failure messages for missing files  /*{{{*/
 // ---------------------------------------------------------------------
                                                                        /*}}}*/
 // AcqIndexTrans::Failed - Silence failure messages for missing files  /*{{{*/
 // ---------------------------------------------------------------------
@@ -749,8 +798,7 @@ void pkgAcqIndexTrans::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
    Item::Failed(Message,Cnf);
 }
                                                                        /*}}}*/
    Item::Failed(Message,Cnf);
 }
                                                                        /*}}}*/
-
-pkgAcqMetaSig::pkgAcqMetaSig(pkgAcquire *Owner,
+pkgAcqMetaSig::pkgAcqMetaSig(pkgAcquire *Owner,                                /*{{{*/
                             string URI,string URIDesc,string ShortDesc,
                             string MetaIndexURI, string MetaIndexURIDesc,
                             string MetaIndexShortDesc,
                             string URI,string URIDesc,string ShortDesc,
                             string MetaIndexURI, string MetaIndexURIDesc,
                             string MetaIndexShortDesc,
@@ -773,16 +821,19 @@ pkgAcqMetaSig::pkgAcqMetaSig(pkgAcquire *Owner,
    Desc.Owner = this;
    Desc.ShortDesc = ShortDesc;
    Desc.URI = URI;
    Desc.Owner = this;
    Desc.ShortDesc = ShortDesc;
    Desc.URI = URI;
-   
       
    string Final = _config->FindDir("Dir::State::lists");
    Final += URItoFileName(RealURI);
    struct stat Buf;
    if (stat(Final.c_str(),&Buf) == 0)
    {
       
    string Final = _config->FindDir("Dir::State::lists");
    Final += URItoFileName(RealURI);
    struct stat Buf;
    if (stat(Final.c_str(),&Buf) == 0)
    {
-      // File was already in place.  It needs to be re-verified
-      // because Release might have changed, so Move it into partial
-      Rename(Final,DestFile);
+      // File was already in place.  It needs to be re-downloaded/verified
+      // because Release might have changed, we do give it a differnt
+      // name than DestFile because otherwise the http method will
+      // send If-Range requests and there are too many broken servers
+      // out there that do not understand them
+      LastGoodSig = DestFile+".reverify";
+      Rename(Final,LastGoodSig);
    }
 
    QueueURI(Desc);
    }
 
    QueueURI(Desc);
@@ -794,7 +845,7 @@ pkgAcqMetaSig::pkgAcqMetaSig(pkgAcquire *Owner,
 string pkgAcqMetaSig::Custom600Headers()
 {
    struct stat Buf;
 string pkgAcqMetaSig::Custom600Headers()
 {
    struct stat Buf;
-   if (stat(DestFile.c_str(),&Buf) != 0)
+   if (stat(LastGoodSig.c_str(),&Buf) != 0)
       return "\nIndex-File: true";
 
    return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
       return "\nIndex-File: true";
 
    return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
@@ -824,13 +875,19 @@ void pkgAcqMetaSig::Done(string Message,unsigned long Size,string MD5,
 
    Complete = true;
 
 
    Complete = true;
 
+   // put the last known good file back on i-m-s hit (it will
+   // be re-verified again)
+   // Else do nothing, we have the new file in DestFile then
+   if(StringToBool(LookupTag(Message,"IMS-Hit"),false) == true)
+      Rename(LastGoodSig, DestFile);
+
    // queue a pkgAcqMetaIndex to be verified against the sig we just retrieved
    new pkgAcqMetaIndex(Owner, MetaIndexURI, MetaIndexURIDesc, MetaIndexShortDesc,
                       DestFile, IndexTargets, MetaIndexParser);
 
 }
                                                                        /*}}}*/
    // queue a pkgAcqMetaIndex to be verified against the sig we just retrieved
    new pkgAcqMetaIndex(Owner, MetaIndexURI, MetaIndexURIDesc, MetaIndexShortDesc,
                       DestFile, IndexTargets, MetaIndexParser);
 
 }
                                                                        /*}}}*/
-void pkgAcqMetaSig::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
+void pkgAcqMetaSig::Failed(string Message,pkgAcquire::MethodConfig *Cnf)/*{{{*/
 {
    string Final = _config->FindDir("Dir::State::lists") + URItoFileName(RealURI);
 
 {
    string Final = _config->FindDir("Dir::State::lists") + URItoFileName(RealURI);
 
@@ -840,7 +897,7 @@ void pkgAcqMetaSig::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
       Item::Failed(Message,Cnf);
       // move the sigfile back on transient network failures 
       if(FileExists(DestFile))
       Item::Failed(Message,Cnf);
       // move the sigfile back on transient network failures 
       if(FileExists(DestFile))
-        Rename(DestFile,Final);
+        Rename(LastGoodSig,Final);
 
       // set the status back to , Item::Failed likes to reset it
       Status = pkgAcquire::Item::StatTransientNetworkError;
 
       // set the status back to , Item::Failed likes to reset it
       Status = pkgAcquire::Item::StatTransientNetworkError;
@@ -866,8 +923,8 @@ void pkgAcqMetaSig::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
    
    Item::Failed(Message,Cnf);
 }
    
    Item::Failed(Message,Cnf);
 }
-
-pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire *Owner,
+                                                                       /*}}}*/
+pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire *Owner,                    /*{{{*/
                                 string URI,string URIDesc,string ShortDesc,
                                 string SigFile,
                                 const vector<struct IndexTarget*>* IndexTargets,
                                 string URI,string URIDesc,string ShortDesc,
                                 string SigFile,
                                 const vector<struct IndexTarget*>* IndexTargets,
@@ -886,7 +943,6 @@ pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire *Owner,
 
    QueueURI(Desc);
 }
 
    QueueURI(Desc);
 }
-
                                                                        /*}}}*/
 // pkgAcqMetaIndex::Custom600Headers - Insert custom request headers   /*{{{*/
 // ---------------------------------------------------------------------
                                                                        /*}}}*/
 // pkgAcqMetaIndex::Custom600Headers - Insert custom request headers   /*{{{*/
 // ---------------------------------------------------------------------
@@ -902,8 +958,8 @@ string pkgAcqMetaIndex::Custom600Headers()
    
    return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
 }
    
    return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
 }
-
-void pkgAcqMetaIndex::Done(string Message,unsigned long Size,string Hash,
+                                                                       /*}}}*/
+void pkgAcqMetaIndex::Done(string Message,unsigned long Size,string Hash,      /*{{{*/
                           pkgAcquire::MethodConfig *Cfg)
 {
    Item::Done(Message,Size,Hash,Cfg);
                           pkgAcquire::MethodConfig *Cfg)
 {
    Item::Done(Message,Size,Hash,Cfg);
@@ -944,8 +1000,8 @@ void pkgAcqMetaIndex::Done(string Message,unsigned long Size,string Hash,
       }
    }
 }
       }
    }
 }
-
-void pkgAcqMetaIndex::RetrievalDone(string Message)
+                                                                       /*}}}*/
+void pkgAcqMetaIndex::RetrievalDone(string Message)                    /*{{{*/
 {
    // 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)
@@ -983,8 +1039,8 @@ void pkgAcqMetaIndex::RetrievalDone(string Message)
    chmod(FinalFile.c_str(),0644);
    DestFile = FinalFile;
 }
    chmod(FinalFile.c_str(),0644);
    DestFile = FinalFile;
 }
-
-void pkgAcqMetaIndex::AuthDone(string Message)
+                                                                       /*}}}*/
+void pkgAcqMetaIndex::AuthDone(string Message)                         /*{{{*/
 {
    // At this point, the gpgv method has succeeded, so there is a
    // valid signature from a key in the trusted keyring.  We
 {
    // At this point, the gpgv method has succeeded, so there is a
    // valid signature from a key in the trusted keyring.  We
@@ -1017,8 +1073,8 @@ void pkgAcqMetaIndex::AuthDone(string Message)
    Rename(SigFile,VerifiedSigFile);
    chmod(VerifiedSigFile.c_str(),0644);
 }
    Rename(SigFile,VerifiedSigFile);
    chmod(VerifiedSigFile.c_str(),0644);
 }
-
-void pkgAcqMetaIndex::QueueIndexes(bool verify)
+                                                                       /*}}}*/
+void pkgAcqMetaIndex::QueueIndexes(bool verify)                                /*{{{*/
 {
    for (vector <struct IndexTarget*>::const_iterator Target = IndexTargets->begin();
         Target != IndexTargets->end();
 {
    for (vector <struct IndexTarget*>::const_iterator Target = IndexTargets->begin();
         Target != IndexTargets->end();
@@ -1060,8 +1116,8 @@ void pkgAcqMetaIndex::QueueIndexes(bool verify)
                            (*Target)->ShortDesc, ExpectedIndexHash);
    }
 }
                            (*Target)->ShortDesc, ExpectedIndexHash);
    }
 }
-
-bool pkgAcqMetaIndex::VerifyVendor(string Message)
+                                                                       /*}}}*/
+bool pkgAcqMetaIndex::VerifyVendor(string Message)                     /*{{{*/
 {
 //    // Maybe this should be made available from above so we don't have
 //    // to read and parse it every time?
 {
 //    // Maybe this should be made available from above so we don't have
 //    // to read and parse it every time?
@@ -1147,9 +1203,8 @@ bool pkgAcqMetaIndex::VerifyVendor(string Message)
 
    return true;
 }
 
    return true;
 }
-                                                                       /*}}}*/
-// pkgAcqMetaIndex::Failed - no Release file present or no signature
-//      file present                                           /*{{{*/
+                                                                       /*}}}*/
+// pkgAcqMetaIndex::Failed - no Release file present or no signature file present      /*{{{*/
 // ---------------------------------------------------------------------
 /* */
 void pkgAcqMetaIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
 // ---------------------------------------------------------------------
 /* */
 void pkgAcqMetaIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
@@ -1186,9 +1241,7 @@ void pkgAcqMetaIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
    // back to queueing Packages files without verification
    QueueIndexes(false);
 }
    // back to queueing Packages files without verification
    QueueIndexes(false);
 }
-
                                                                        /*}}}*/
                                                                        /*}}}*/
-
 // AcqArchive::AcqArchive - Constructor                                        /*{{{*/
 // ---------------------------------------------------------------------
 /* This just sets up the initial fetch environment and queues the first
 // AcqArchive::AcqArchive - Constructor                                        /*{{{*/
 // ---------------------------------------------------------------------
 /* This just sets up the initial fetch environment and queues the first
@@ -1471,14 +1524,13 @@ void pkgAcqArchive::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
    }
 }
                                                                        /*}}}*/
    }
 }
                                                                        /*}}}*/
-// AcqArchive::IsTrusted - Determine whether this archive comes from a
-// trusted source                                                      /*{{{*/
+// AcqArchive::IsTrusted - Determine whether this archive comes from a trusted source /*{{{*/
 // ---------------------------------------------------------------------
 bool pkgAcqArchive::IsTrusted()
 {
    return Trusted;
 }
 // ---------------------------------------------------------------------
 bool pkgAcqArchive::IsTrusted()
 {
    return Trusted;
 }
-
+                                                                       /*}}}*/
 // AcqArchive::Finished - Fetching has finished, tidy up               /*{{{*/
 // ---------------------------------------------------------------------
 /* */
 // AcqArchive::Finished - Fetching has finished, tidy up               /*{{{*/
 // ---------------------------------------------------------------------
 /* */
@@ -1490,7 +1542,6 @@ void pkgAcqArchive::Finished()
    StoreFilename = string();
 }
                                                                        /*}}}*/
    StoreFilename = string();
 }
                                                                        /*}}}*/
-
 // AcqFile::pkgAcqFile - Constructor                                   /*{{{*/
 // ---------------------------------------------------------------------
 /* The file is added to the queue */
 // AcqFile::pkgAcqFile - Constructor                                   /*{{{*/
 // ---------------------------------------------------------------------
 /* The file is added to the queue */