Merge branch 'maint'

* maint:
  Make git-prune submodule aware (and fix a SEGFAULT in the process)

diff --cc reachable.c
index ff3dd34962ec69320a67a4823b844755ebfe0e7d,c1aee603e7df68d6a12ce25b183c478d7da6ab4e..6383401e2dd6bef3251a105ac136312dfdcdeb3c
--- 1/reachable.c
--- 2/reachable.c
+++ b/reachable.c
@@@ -47,6 -55,8 +55,8 @@@ static void process_tree(struct tree *t
        while (tree_entry(&desc, &entry)) {
                if (S_ISDIR(entry.mode))
                        process_tree(lookup_tree(entry.sha1), p, &me, entry.path);
 -              else if (S_ISDIRLNK(entry.mode))
++              else if (S_ISGITLINK(entry.mode))
+                       process_gitlink(entry.sha1, p, &me, entry.path);
                else
                        process_blob(lookup_blob(entry.sha1), p, &me, entry.path);
        }
@@@ -159,6 -169,16 +169,16 @@@ static void add_cache_refs(struct rev_i
  
        read_cache();
        for (i = 0; i < active_nr; i++) {
 -              if (S_ISDIRLNK(ntohl(active_cache[i]->ce_mode)))
+               /*
+                * The index can contain blobs and GITLINKs, GITLINKs are hashes
+                * that don't actually point to objects in the repository, it's
+                * almost guaranteed that they are NOT blobs, so we don't call
+                * lookup_blob() on them, to avoid populating the hash table
+                * with invalid information
+                */
++              if (S_ISGITLINK(ntohl(active_cache[i]->ce_mode)))
+                       continue;
+ 
                lookup_blob(active_cache[i]->sha1);
                /*
                 * We could add the blobs to the pending list, but quite