bundle, fast-import: detect write failure

I noticed some unchecked writes.  This fixes them.

* bundle.c (create_bundle): Die upon write failure.
* fast-import.c (keep_pack): Die upon write or close failure.

Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

bundle.c

@@ -320,9 +320,9 @@ int create_bundle(struct bundle_header *header, const char *path,
 	for (i = 0; i < revs.pending.nr; i++) {
 		struct object *object = revs.pending.objects[i].item;
 		if (object->flags & UNINTERESTING)
-			write(rls.in, "^", 1);
+			write_or_die(rls.in, "^", 1);
-		write(rls.in, sha1_to_hex(object->sha1), 40);
+		write_or_die(rls.in, sha1_to_hex(object->sha1), 40);
-		write(rls.in, "\n", 1);
+		write_or_die(rls.in, "\n", 1);
 	}
 	if (finish_command(&rls))
 		return error ("pack-objects died");

fast-import.c

@@ -878,8 +878,9 @@ static char *keep_pack(char *curr_index_name)
 	keep_fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
 	if (keep_fd < 0)
 		die("cannot create keep file");
-	write(keep_fd, keep_msg, strlen(keep_msg));
+	write_or_die(keep_fd, keep_msg, strlen(keep_msg));
-	close(keep_fd);
+	if (close(keep_fd))
+		die("failed to write keep file");
 
 	snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
 		 get_object_directory(), sha1_to_hex(pack_data->sha1));