Notice tree objects with duplicate entries.

This is a follow-up fix to the earlier "Notice index that has
path and path/file and refuse to write such a tree" patch.
With this fix, git-fsck-cache complains if a tree object stores
more than one entries with the same name.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/fsck-cache.c b/fsck-cache.c
index d59d57ea76347c534908d2d7fa851044b1af4801..a00702b79f7169ef3da7d60e9bbbe9ccf237e673 100644 (file)
--- a/fsck-cache.c
+++ b/fsck-cache.c
@@ -62,6 +62,9 @@ static void check_connectivity(void)
  * So a directory called "a" is ordered _after_ a file
  * called "a.c", because "a/" sorts after "a.c".
  */
+#define TREE_UNORDERED (-1)
+#define TREE_HAS_DUPS  (-2)
+
 static int verify_ordered(struct tree_entry_list *a, struct tree_entry_list *b)
 {
        int len1 = strlen(a->name);
@@ -74,7 +77,7 @@ static int verify_ordered(struct tree_entry_list *a, struct tree_entry_list *b)
        if (cmp < 0)
                return 0;
        if (cmp > 0)
-               return -1;
+               return TREE_UNORDERED;
 
        /*
         * Ok, the first <len> characters are the same.
@@ -83,11 +86,18 @@ static int verify_ordered(struct tree_entry_list *a, struct tree_entry_list *b)
         */
        c1 = a->name[len];
        c2 = b->name[len];
+       if (!c1 && !c2)
+               /*
+                * git-write-tree used to write out a nonsense tree that has
+                * entries with the same name, one blob and one tree.  Make
+                * sure we do not have duplicate entries.
+                */
+               return TREE_HAS_DUPS;
        if (!c1 && a->directory)
                c1 = '/';
        if (!c2 && b->directory)
                c2 = '/';
-       return c1 < c2 ? 0 : -1;
+       return c1 < c2 ? 0 : TREE_UNORDERED;
 }
 
 static int fsck_tree(struct tree *item)
@@ -123,10 +133,18 @@ static int fsck_tree(struct tree *item)
                }
 
                if (last) {
-                       if (verify_ordered(last, entry) < 0) {
+                       switch (verify_ordered(last, entry)) {
+                       case TREE_UNORDERED:
                                fprintf(stderr, "tree %s not ordered\n",
                                        sha1_to_hex(item->object.sha1));
                                return -1;
+                       case TREE_HAS_DUPS:
+                               fprintf(stderr, "tree %s has duplicate entries for '%s'\n",
+                                       sha1_to_hex(item->object.sha1),
+                                       entry->name);
+                               return -1;
+                       default:
+                               break;
                        }
                }