--- a/src/Pure/Isar/args.ML Sun Feb 23 21:45:27 2014 +0100
+++ b/src/Pure/Isar/args.ML Sun Feb 23 21:53:01 2014 +0100
@@ -291,8 +291,8 @@
(case Scan.error (Scan.finite' Token.stopper (Scan.option scan)) (st, args) of
(SOME x, (st', [])) => (x, st')
| (_, (_, args')) =>
- error (kind ^ " " ^ quote s ^ Position.here pos ^ ": bad arguments\n " ^
- space_implode " " (map Token.unparse args')));
+ error (kind ^ " " ^ quote s ^ Position.here pos ^ ": bad arguments" ^
+ (if null args' then "" else "\n " ^ space_implode " " (map Token.unparse args'))));
fun context_syntax kind scan src = apsnd Context.the_proof o syntax kind scan src o Context.Proof;