don't abort blame in annotate_line() if lines are out of range
diff --git a/lib/blame.c b/lib/blame.c
index 3bb1f98..ea25dfb 100644
--- a/lib/blame.c
+++ b/lib/blame.c
@@ -103,7 +103,7 @@ annotate_line(struct got_blame *blame, int lineno, struct got_object_id *id,
struct got_blame_line *line;
if (lineno < 1 || lineno > blame->nlines)
- return got_error(GOT_ERR_RANGE);
+ return NULL;
line = &blame->lines[lineno - 1];
if (line->annotated)