abstract version hash comparison a bit

In #737085 we see that apt can be confused if informations about
versions only differ slightly. This commit adds a way of at least adding
a few more data points with the next abi break to help a bit with it.

Git-Dch: Ignore

2 files changed, 24 insertions, 0 deletions

diff --git a/apt-pkg/deb/deblistparser.cc b/apt-pkg/deb/deblistparser.cc
index 18b8b931d..a1bcfb710 100644
--- a/apt-pkg/deb/deblistparser.cc
+++ b/apt-pkg/deb/deblistparser.cc
@@ -938,3 +938,24 @@ unsigned char debListParser::GetPrio(string Str)
    return Out;
 }
 									/*}}}*/
+#if (APT_PKG_MAJOR >= 4 && APT_PKG_MINOR >= 13)
+bool debListParser::SameVersion(unsigned short const Hash,		/*{{{*/
+      pkgCache::VerIterator const &Ver)
+{
+   if (pkgCacheGenerator::ListParser::SameVersion(Hash, Ver) == false)
+      return false;
+   // status file has no (Download)Size, but all others are fair game
+   // status file is parsed last, so the first version we encounter is
+   // probably also the version we have downloaded
+   unsigned long long const Size = Section.FindULL("Size");
+   if (Size != 0 && Size != Ver->Size)
+      return false;
+   // available everywhere, but easier to check here than to include in VersionHash
+   unsigned char MultiArch = ParseMultiArch(false);
+   if (MultiArch != Ver->MultiArch)
+      return false;
+   // for all practical proposes (we can check): same version
+   return true;
+}
+									/*}}}*/
+#endif
diff --git a/apt-pkg/deb/deblistparser.h b/apt-pkg/deb/deblistparser.h
index 03733ae8c..286244cc9 100644
--- a/apt-pkg/deb/deblistparser.h
+++ b/apt-pkg/deb/deblistparser.h
@@ -70,6 +70,9 @@ class debListParser : public pkgCacheGenerator::ListParser
    virtual std::string DescriptionLanguage();
    virtual MD5SumValue Description_md5();
    virtual unsigned short VersionHash();
+#if (APT_PKG_MAJOR >= 4 && APT_PKG_MINOR >= 13)
+   virtual bool SameVersion(unsigned short const Hash, pkgCache::VerIterator const &Ver);
+#endif
    virtual bool UsePackage(pkgCache::PkgIterator &Pkg,
 			   pkgCache::VerIterator &Ver);
    virtual unsigned long Offset() {return iOffset;};