Merge branch 'ys/fsck-commit-parsing'

* ys/fsck-commit-parsing:
  fsck.c:fsck_commit(): use skip_prefix() to verify and skip constant
  fsck.c:fsck_ident(): ident points at a const string

diff --cc fsck.c
index 64bf279,6aab23b..b3022ad
--- 1/fsck.c
--- 2/fsck.c
+++ b/fsck.c
@@@ -243,10 -243,8 +243,10 @@@ static int fsck_tree(struct tree *item
        return retval;
  }
  
- static int fsck_ident(char **ident, struct object *obj, fsck_error error_func)
+ static int fsck_ident(const char **ident, struct object *obj, fsck_error error_func)
  {
 +      char *end;
 +
        if (**ident == '<')
                return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing space before email");
        *ident += strcspn(*ident, "<>\n");
@@@ -290,15 -287,20 +290,17 @@@ static int fsck_commit(struct commit *c
        int parents = 0;
        int err;
  
-       if (memcmp(buffer, "tree ", 5))
 -      if (commit->date == ULONG_MAX)
 -              return error_func(&commit->object, FSCK_ERROR, "invalid author/committer line");
 -
+       buffer = skip_prefix(buffer, "tree ");
+       if (!buffer)
                return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'tree' line");
-       if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
+       if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n')
                return error_func(&commit->object, FSCK_ERROR, "invalid 'tree' line format - bad sha1");
-       buffer += 46;
-       while (!memcmp(buffer, "parent ", 7)) {
-               if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
+       buffer += 41;
+       while ((tmp = skip_prefix(buffer, "parent "))) {
+               buffer = tmp;
+               if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n')
                        return error_func(&commit->object, FSCK_ERROR, "invalid 'parent' line format - bad sha1");
-               buffer += 48;
+               buffer += 41;
                parents++;
        }
        graft = lookup_commit_graft(commit->object.sha1);