Fix the repeat count checking in String.prototype.repeat (#2959)

This patch fixes #2948

Co-authored-by: Gabor Loki loki@inf.u-szeged.hu
JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu

Author: rerobika

jerry-core/ecma/builtin-objects/ecma-builtin-string-prototype.c

@@ -2198,7 +2198,7 @@ ecma_builtin_string_prototype_object_repeat (ecma_value_t this_arg, /**< this ar
   bool isNan = ecma_number_is_nan (length_number);
 
   /* 6, 7 */
-  if (length < 0 || (!isNan && ecma_number_is_infinity (length_number)))
+  if (length_number < 0 || (!isNan && ecma_number_is_infinity (length_number)))
   {
     ecma_deref_ecma_string (original_string_p);
     return ecma_raise_range_error (ECMA_ERR_MSG ("Invalid count value"));

tests/jerry/es2015/regression-test-issue-2948.js

@@ -0,0 +1,20 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+try {
+  new (new Object()).constructor().constructor('abcdefghi').repeat(-4956799914495204378)
+  assert (false);
+} catch (e) {
+  assert (e instanceof RangeError);
+}