parse version correctly from binary Source field

In commit a221efc331693f8905da870141756c892911c433 I promoted the source
package name and version to the binary cache for faster access by e.g.
EDSP, but due to changing the interpretation length to soon we always
ignored the version part of the Source field, so that packages ended up
having the binary version as source version – which while usually just
fine it is wrong for binary rebuilds.

Closes: 812492

apt-pkg/deb/deblistparser.cc

@@ -154,7 +154,6 @@ bool debListParser::NewVersion(pkgCache::VerIterator &Ver)
 
       if (Space != NULL)
       {
-	 Stop = Space;
 	 const char * const Open = (const char * const) memchr(Space, '(', Stop - Space);
 	 if (likely(Open != NULL))
 	 {
@@ -169,6 +168,7 @@ bool debListParser::NewVersion(pkgCache::VerIterator &Ver)
 	       }
 	    }
 	 }
+	 Stop = Space;
       }
 
       std::string const pkgname(Start, Stop - Start);

apt-pkg/pkgcache.cc

@@ -59,7 +59,7 @@ pkgCache::Header::Header()
    /* Whenever the structures change the major version should be bumped,
       whenever the generator changes the minor version should be bumped. */
    APT_HEADER_SET(MajorVersion, 10);
-   APT_HEADER_SET(MinorVersion, 4);
+   APT_HEADER_SET(MinorVersion, 5);
    APT_HEADER_SET(Dirty, false);
 
    APT_HEADER_SET(HeaderSz, sizeof(pkgCache::Header));

test/integration/test-apt-get-source

@@ -15,6 +15,12 @@ insertpackage 'wheezy' 'unreleated-package' 'all' '1.0'
 insertpackage 'unstable' 'foo' 'all' '2.0'
 insertsource 'unstable' 'foo' 'all' '2.0'
 
+# binary packages with Source-field
+insertpackage 'unstable' 'bin' 'i386' '3-2+b1' 'Source: bin (3-2)'
+insertsource 'unstable' 'bin' 'any' '3-2'
+insertpackage 'stable' 'bin' 'i386' '2-2+b1' 'Source: bin-backport (2-2)'
+insertsource 'stable' 'bin-backport' 'any' '2-2'
+
 # its possible to have multiple src versions in the sources file, ensure
 # to pick the correct one in this case (bts #731853)
 insertsource 'stable' 'foo' 'all' '1.5'
@@ -37,6 +43,7 @@ insertsource 'unstable' 'baz' 'all' '1.5'
 
 # ensure we really have the situation we wanted (first 2.0 is foo above)
 testequal 'Version: 2.0
+Version: 3-2
 Version: 2.0
 Version: 1.5' grep '^Version:' aptarchive/dists/unstable/main/source/Sources
 
@@ -137,3 +144,16 @@ git clone git://anonscm.debian.org/bar/bar.git -b debian/experimental
 to retrieve the latest (possibly unreleased) updates to the package.
 Need to get 0 B/25 B of source archives.
 Fetch source bar" aptget source bar -s
+
+testsuccessequal "$HEADER
+Need to get 0 B/25 B of source archives.
+Fetch source bin" aptget source bin -s -q
+testsuccessequal "$HEADER
+Selected version '3-2' (unstable) for bin
+Need to get 0 B/25 B of source archives.
+Fetch source bin" aptget source bin/unstable -s -q
+testsuccessequal "$HEADER
+Picking 'bin-backport' as source package instead of 'bin'
+Selected version '2-2' (stable) for bin-backport
+Need to get 0 B/43 B of source archives.
+Fetch source bin-backport" aptget source bin/stable -s -q