1 files changed, 27 insertions, 0 deletions
diff --git a/deps/v8/test/mjsunit/regress/regress-821137.js b/deps/v8/test/mjsunit/regress/regress-821137.js
new file mode 100644
index 0000000000..639b3b998a
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/regress-821137.js
@@ -0,0 +1,27 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Tests that creating an iterator that shrinks the array populated by
+// Array.from does not lead to out of bounds writes.
+let oobArray = [];
+let maxSize = 1028 * 8;
+Array.from.call(function() { return oobArray }, {[Symbol.iterator] : _ => (
+  {
+    counter : 0,
+    next() {
+      let result = this.counter++;
+      if (this.counter > maxSize) {
+        oobArray.length = 0;
+        return {done: true};
+      } else {
+        return {value: result, done: false};
+      }
+    }
+  }
+) });
+assertEquals(oobArray.length, maxSize);
+
+// iterator reset the length to 0 just before returning done, so this will crash
+// if the backing store was not resized correctly.
+oobArray[oobArray.length - 1] = 0x41414141;