+ int len1 = strlen(a->name);
+ int len2 = strlen(b->name);
+ int len = len1 < len2 ? len1 : len2;
+ unsigned char c1, c2;
+ int cmp;
+
+ cmp = memcmp(a->name, b->name, len);
+ if (cmp < 0)
+ return 0;
+ if (cmp > 0)
+ return TREE_UNORDERED;
+
+ /*
+ * Ok, the first <len> characters are the same.
+ * Now we need to order the next one, but turn
+ * a '\0' into a '/' for a directory entry.
+ */
+ 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 : TREE_UNORDERED;
+}
+
+static int fsck_tree(struct tree *item)
+{
+ int has_full_path = 0;
+ struct tree_entry_list *entry, *last;
+
+ last = NULL;
+ for (entry = item->entries; entry; entry = entry->next) {
+ if (strchr(entry->name, '/'))
+ has_full_path = 1;
+
+ switch (entry->mode) {
+ /*
+ * Standard modes..
+ */
+ case S_IFREG | 0755:
+ case S_IFREG | 0644:
+ case S_IFLNK:
+ case S_IFDIR:
+ break;
+ /*
+ * This is nonstandard, but we had a few of these
+ * early on when we honored the full set of mode
+ * bits..
+ */
+ case S_IFREG | 0664:
+ break;
+ default:
+ printf("tree %s has entry %o %s\n",
+ sha1_to_hex(item->object.sha1),
+ entry->mode, entry->name);
+ }
+
+ if (last) {
+ 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;
+ }
+ }
+
+ last = entry;