check return value from diff_setup_done()

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

builtin-diff.c

@@ -253,7 +253,8 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 	argc = setup_revisions(argc, argv, &rev, NULL);
 	if (!rev.diffopt.output_format) {
 		rev.diffopt.output_format = DIFF_FORMAT_PATCH;
-		diff_setup_done(&rev.diffopt);
+		if (diff_setup_done(&rev.diffopt) < 0)
+			die("diff_setup_done failed");
 	}
 
 	/* Do we have --cached and not have a pending object, then

revision.c

@@ -936,7 +936,8 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 			revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 	}
 	revs->diffopt.abbrev = revs->abbrev;
-	diff_setup_done(&revs->diffopt);
+	if (diff_setup_done(&revs->diffopt) < 0)
+		die("diff_setup_done failed");
 
 	return left;
 }