A positional Hash is not keyword arguments [Bug #18632]

eval.c

@@ -695,17 +695,18 @@ rb_interrupt(void)
 enum {raise_opt_cause, raise_max_opt}; /*< \private */
 
 static int
-extract_raise_opts(int argc, const VALUE *argv, VALUE *opts)
+extract_raise_opts(int argc, VALUE *argv, VALUE *opts)
 {
     int i;
     if (argc > 0) {
-	VALUE opt = argv[argc-1];
-	if (RB_TYPE_P(opt, T_HASH)) {
+	VALUE opt;
+	argc = rb_scan_args(argc, argv, "*:", NULL, &opt);
+	if (!NIL_P(opt)) {
 	    if (!RHASH_EMPTY_P(opt)) {
 		ID keywords[1];
 		CONST_ID(keywords[0], "cause");
 		rb_get_kwargs(opt, keywords, 0, -1-raise_max_opt, opts);
-		if (RHASH_EMPTY_P(opt)) --argc;
+		if (!RHASH_EMPTY_P(opt)) argv[argc++] = opt;
 		return argc;
 	    }
 	}

test/ruby/test_exception.rb

@@ -807,6 +807,7 @@ end.join
     cause = ArgumentError.new("foobar")
     e = assert_raise(RuntimeError) {raise msg, cause: cause}
     assert_same(cause, e.cause)
+    assert_raise(TypeError) {raise msg, {cause: cause}}
   end
 
   def test_cause_with_no_arguments