1 files changed, 38 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/RegExp/named-groups/groups-object-subclass-sans.js b/js/src/tests/test262/built-ins/RegExp/named-groups/groups-object-subclass-sans.js
new file mode 100644
index 0000000000..a6674a6fb1
--- /dev/null
+++ b/js/src/tests/test262/built-ins/RegExp/named-groups/groups-object-subclass-sans.js
@@ -0,0 +1,38 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: >
+  Test the groups object on RegExp subclass results that do not have their own.
+esid: sec-regexpbuiltinexec
+features: [regexp-named-groups]
+info: |
+  Runtime Semantics: RegExpBuiltinExec ( R, S )
+    24. If _R_ contains any |GroupName|, then
+      a. Let _groups_ be ObjectCreate(*null*).
+    25. Else,
+      a. Let _groups_ be *undefined*.
+    26. Perform ! CreateDataProperty(_A_, `"groups"`, _groups_).
+---*/
+
+class FakeRegExp extends RegExp {
+  exec(subject) {
+    const fakeResult = ["ab", "a"];
+    fakeResult.index = 0;
+    // `groups` is not set, triggering prototype lookup.
+    return fakeResult;
+  }
+};
+
+const re = new FakeRegExp();
+const result = re.exec("ab");
+assert.sameValue(Object.getPrototypeOf(result), Array.prototype);
+assert.sameValue(false, result.hasOwnProperty("groups"));
+
+Array.prototype.groups = { a: "b" };
+Object.getPrototypeOf(Array.prototype.groups).b = "c";
+assert.sameValue("b", "ab".replace(re, "$<a>"));
+assert.sameValue("c", "ab".replace(re, "$<b>"));
+Array.prototype.groups = undefined;
+
+reportCompare(0, 0);