Add fast-path check to ecma_builtin_array_prototype_slice (#3480)

Fixes #3459

JerryScript-DCO-1.0-Signed-off-by: Peter Marki marpeter@inf.u-szeged.hu

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

@@ -827,6 +827,7 @@ ecma_builtin_array_prototype_object_slice (ecma_value_t arg1, /**< start */
 
   JERRY_ASSERT (start <= len && end <= len);
 
+  bool use_fast_path = ecma_op_object_is_fast_array (obj_p);
 #if ENABLED (JERRY_ES2015)
   ecma_value_t new_array = ecma_op_array_species_create (obj_p, 0);
 
@@ -834,6 +835,7 @@ ecma_builtin_array_prototype_object_slice (ecma_value_t arg1, /**< start */
   {
     return new_array;
   }
+  use_fast_path &= ecma_op_object_is_fast_array (ecma_get_object_from_value (new_array));
 #else /* !ENABLED (JERRY_ES2015) */
   ecma_value_t new_array = ecma_op_create_array_object (NULL, 0, false);
   JERRY_ASSERT (!ECMA_IS_VALUE_ERROR (new_array));
@@ -844,7 +846,7 @@ ecma_builtin_array_prototype_object_slice (ecma_value_t arg1, /**< start */
   /* 9. */
   uint32_t n = 0;
 
-  if (ecma_op_object_is_fast_array (obj_p))
+  if (use_fast_path)
   {
     ecma_extended_object_t *ext_from_obj_p = (ecma_extended_object_t *) obj_p;
 

tests/jerry/es2015/regression-test-issue-3459.js

@@ -0,0 +1,21 @@
+// 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.
+
+class MyOtherArray {}
+
+class MyNonArray extends Array {
+  static [Symbol.species] () {}
+}
+
+(() => MyNonArray)().prototype.slice.call(new MyNonArray((0) === 1))