git cherry-pick: do not dereference a potential NULL pointer

[thirdparty/git.git] / sequencer.c

diff --git a/sequencer.c b/sequencer.c
index 4e3af82442b949a387bb630c77c2f3f4add0bb03..72cb4ff82ca0b98f4074e1af3fb491df691a7268 100644 (file)
--- a/sequencer.c
+++ b/sequencer.c
@@ -261,9 +261,17 @@ static int is_index_unchanged(void)
                return error(_("Could not resolve HEAD commit\n"));
 
        head_commit = lookup_commit(head_sha1);
-       if (!head_commit || parse_commit(head_commit))
-               return error(_("could not parse commit %s\n"),
-                            sha1_to_hex(head_commit->object.sha1));
+
+       /*
+        * If head_commit is NULL, check_commit, called from
+        * lookup_commit, would have indicated that head_commit is not
+        * a commit object already.  parse_commit() will return failure
+        * without further complaints in such a case.  Otherwise, if
+        * the commit is invalid, parse_commit() will complain.  So
+        * there is nothing for us to say here.  Just return failure.
+        */
+       if (parse_commit(head_commit))
+               return -1;
 
        if (!active_cache_tree)
                active_cache_tree = cache_tree();