git-annotate: fix -S on graft file with comments.

The graft file can contain comment lines and read_graft_line can
return NULL for such an input, which should be skipped by the
reader.

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

diff --git a/builtin-blame.c b/builtin-blame.c
index 16660221c30b0e3b1e1bd4cbc5559e3f162ae05a..066dee743e9fdd80478395c605d9afc4682600c6 100644 (file)
--- a/builtin-blame.c
+++ b/builtin-blame.c
@@ -1407,7 +1407,8 @@ static int read_ancestry(const char *graft_file)
                /* The format is just "Commit Parent1 Parent2 ...\n" */
                int len = strlen(buf);
                struct commit_graft *graft = read_graft_line(buf, len);
-               register_commit_graft(graft, 0);
+               if (graft)
+                       register_commit_graft(graft, 0);
        }
        fclose(fp);
        return 0;