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 --combined fsck.c
index 64bf279fd7e42da1921a65d725007c52c7ddc5fb,6aab23b84502095fef98f9c1b4fa39d586a74085..b3022ad983a2d26cc24600ffa8356b851efd98ab
--- 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");
@@@ -266,11 -264,10 +266,11 @@@
        (*ident)++;
        if (**ident == '0' && (*ident)[1] != ' ')
                return error_func(obj, FSCK_ERROR, "invalid author/committer line - zero-padded date");
 -      *ident += strspn(*ident, "0123456789");
 -      if (**ident != ' ')
 +      if (date_overflows(strtoul(*ident, &end, 10)))
 +              return error_func(obj, FSCK_ERROR, "invalid author/committer line - date causes integer overflow");
 +      if (end == *ident || *end != ' ')
                return error_func(obj, FSCK_ERROR, "invalid author/committer line - bad date");
 -      (*ident)++;
 +      *ident = end + 1;
        if ((**ident != '+' && **ident != '-') ||
            !isdigit((*ident)[1]) ||
            !isdigit((*ident)[2]) ||
@@@ -284,21 -281,26 +284,23 @@@
  
  static int fsck_commit(struct commit *commit, fsck_error error_func)
  {
-       char *buffer = commit->buffer;
+       const char *buffer = commit->buffer, *tmp;
        unsigned char tree_sha1[20], sha1[20];
        struct commit_graft *graft;
        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);
@@@ -322,15 -324,15 +324,15 @@@
                if (p || parents)
                        return error_func(&commit->object, FSCK_ERROR, "parent objects missing");
        }
-       if (memcmp(buffer, "author ", 7))
+       buffer = skip_prefix(buffer, "author ");
+       if (!buffer)
                return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'author' line");
-       buffer += 7;
        err = fsck_ident(&buffer, &commit->object, error_func);
        if (err)
                return err;
-       if (memcmp(buffer, "committer ", strlen("committer ")))
+       buffer = skip_prefix(buffer, "committer ");
+       if (!buffer)
                return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'committer' line");
-       buffer += strlen("committer ");
        err = fsck_ident(&buffer, &commit->object, error_func);
        if (err)
                return err;