avoid segfaults on parse_object failure

Many call-sites of parse_object assume that they will get a
non-NULL return value; this is not the case if we encounter
an error while parsing the object.

This patch adds a wrapper function around parse_object that
handles dying automatically, and uses it anywhere we
immediately try to access the return value as a non-NULL
pointer (i.e., anywhere that we would currently segfault).

This wrapper may also be useful in other places. The most
obvious one is code like:

  o = parse_object(sha1);
  if (!o)
	  die(...);

However, these should not be mechanically converted to
parse_object_or_die, as the die message is sometimes
customized. Later patches can address these sites on a
case-by-case basis.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/bundle.c b/bundle.c
index 8d12816b9d..26ceebdb4b 100644
--- a/bundle.c
+++ b/bundle.c
@@ -279,12 +279,12 @@ int create_bundle(struct bundle_header *header, const char *path,
 		if (buf.len > 0 && buf.buf[0] == '-') {
 			write_or_die(bundle_fd, buf.buf, buf.len);
 			if (!get_sha1_hex(buf.buf + 1, sha1)) {
-				struct object *object = parse_object(sha1);
+				struct object *object = parse_object_or_die(sha1, buf.buf);
 				object->flags |= UNINTERESTING;
 				add_pending_object(&revs, object, xstrdup(buf.buf));
 			}
 		} else if (!get_sha1_hex(buf.buf, sha1)) {
-			struct object *object = parse_object(sha1);
+			struct object *object = parse_object_or_die(sha1, buf.buf);
 			object->flags |= SHOWN;
 		}
 	}
@@ -361,7 +361,7 @@ int create_bundle(struct bundle_header *header, const char *path,
 				 * end up triggering "empty bundle"
 				 * error.
 				 */
-				obj = parse_object(sha1);
+				obj = parse_object_or_die(sha1, e->name);
 				obj->flags |= SHOWN;
 				add_pending_object(&revs, obj, e->name);
 			}