Add a Closes tag for the self-conflict fix:

ignore negative dependencies applying in the same group for M-A:same
packages on the real package name as self-conflicts (Closes: #688863)

debian/changelog

@@ -12,8 +12,8 @@ apt (0.9.7.6) UNRELEASED; urgency=low
       as it is used for arch:all packages as a map to arch:native.
       Otherwise arch comparisons later will see differences (Closes: #689323)
   * apt-pkg/pkgcache.cc:
-    - ignore negative dependencies applying in the same group for
-      M-A:same packages on the real package name as self-conflicts
+    - ignore negative dependencies applying in the same group for M-A:same
+      packages on the real package name as self-conflicts (Closes: #688863)
   * cmdline/apt-cache.cc:
     - print versioned dependency relations in (r)depends if the option
       APT::Cache::ShowVersion is true (default: false) as discussed in