use 'best' hash for source authentication

Collect all hashes we can get from the source record and put them into a
HashStringList so that 'apt-get source' can use it instead of using
always the MD5sum.

We therefore also deprecate the MD5 struct member in favor of the list.

While at it, the parsing of the Files is enhanced so that records which
miss "Files" (aka MD5 checksums) are still searched for other checksums
as they include just as much data, just not with a nice and catchy name.

This is a cherry-pick of 1262d35 with some dirty tricks to preserve ABI.

LP: 1098738

1 files changed, 18 insertions, 3 deletions

diff --git a/apt-pkg/srcrecords.h b/apt-pkg/srcrecords.h
index e000e176a..dde22bd65 100644
--- a/apt-pkg/srcrecords.h
+++ b/apt-pkg/srcrecords.h
@@ -14,6 +14,7 @@
 #define PKGLIB_SRCRECORDS_H
 
 #include <apt-pkg/macros.h>
+#include <apt-pkg/hashes.h>
 
 #include <string>
 #include <vector>
@@ -29,15 +30,28 @@ class pkgSrcRecords
 {
    public:
 
+#if __GNUC__ >= 4
+	// ensure that con- & de-structor don't trigger this warning
+	#pragma GCC diagnostic push
+	#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#endif
    // Describes a single file
    struct File
    {
-      std::string MD5Hash;
-      unsigned long Size;
+      APT_DEPRECATED std::string MD5Hash;
+      APT_DEPRECATED unsigned long Size;
       std::string Path;
       std::string Type;
    };
-   
+   struct File2 : public File
+   {
+      unsigned long long FileSize;
+      HashStringList Hashes;
+   };
+#if __GNUC__ >= 4
+	#pragma GCC diagnostic pop
+#endif
+
    // Abstract parser for each source record
    class Parser
    {
@@ -77,6 +91,7 @@ class pkgSrcRecords
       static const char *BuildDepType(unsigned char const &Type) APT_PURE;
 
       virtual bool Files(std::vector<pkgSrcRecords::File> &F) = 0;
+      bool Files2(std::vector<pkgSrcRecords::File2> &F);
       
       Parser(const pkgIndexFile *Index) : iIndex(Index) {};
       virtual ~Parser() {};