1 files changed, 54 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/RegExp/prototype/exec/failure-g-lastindex-reset.js b/js/src/tests/test262/built-ins/RegExp/prototype/exec/failure-g-lastindex-reset.js
new file mode 100644
index 0000000000..8b3dd5e333
--- /dev/null
+++ b/js/src/tests/test262/built-ins/RegExp/prototype/exec/failure-g-lastindex-reset.js
@@ -0,0 +1,54 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: >
+    lastIndex is read and reset to 0 when global is set and the match fails.
+es6id: 21.2.5.2.2
+info: |
+    21.2.5.2.2 Runtime Semantics: RegExpBuiltinExec ( R, S )
+
+    [...]
+    4. Let flags be R.[[OriginalFlags]].
+    5. If flags contains "g", let global be true, else let global be false.
+    [...]
+    7. If global is false and sticky is false, let lastIndex be 0.
+    8. Else, let lastIndex be ? ToLength(? Get(R, "lastIndex")).
+    [...]
+    12. Repeat, while matchSucceeded is false
+        [...]
+        c. If r is failure, then
+           i. If sticky is true, then
+              1. Perform ? Set(R, "lastIndex", 0, true).
+              2. Return null.
+           ii. Let lastIndex be AdvanceStringIndex(S, lastIndex, fullUnicode).
+---*/
+
+var lastIndexReads;
+var result;
+
+var r = /a/g;
+
+function reset(value) {
+  r.lastIndex = {
+    valueOf: function() {
+      lastIndexReads++;
+      return value;
+    }
+  };
+  lastIndexReads = 0;
+}
+
+reset(42);  // lastIndex beyond end of string.
+result = r.exec('abc');
+assert.sameValue(result, null);
+assert.sameValue(r.lastIndex, 0);
+assert.sameValue(lastIndexReads, 1);
+
+reset(-1);  // No match.
+result = r.exec('nbc');
+assert.sameValue(result, null);
+assert.sameValue(r.lastIndex, 0);
+assert.sameValue(lastIndexReads, 1);
+
+reportCompare(0, 0);