* apt-pkg/algorithms.cc:

  - make sure we have a candidateVer if we check it for downloadability

apt-pkg/algorithms.cc

@@ -497,7 +497,7 @@ void pkgProblemResolver::MakeScores()
          on the same level. We enhance the score of installed packages 
 	 if those are not obsolete
       */
-      if (I->CurrentVer != 0 && Cache[I].CandidateVerIter(Cache).Downloadable())
+      if (I->CurrentVer != 0 && Cache[I].CandidateVer != 0 && Cache[I].CandidateVerIter(Cache).Downloadable())
 	 Score += 1;
    }
 

po/apt-all.pot

@@ -2191,13 +2191,13 @@ msgid ""
 "The package %s needs to be reinstalled, but I can't find an archive for it."
 msgstr ""
 
-#: apt-pkg/algorithms.cc:1061
+#: apt-pkg/algorithms.cc:1066
 msgid ""
 "Error, pkgProblemResolver::Resolve generated breaks, this may be caused by "
 "held packages."
 msgstr ""
 
-#: apt-pkg/algorithms.cc:1063
+#: apt-pkg/algorithms.cc:1068
 msgid "Unable to correct problems, you have held broken packages."
 msgstr ""