1 files changed, 21 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/collections/Map-iterator-remove-6.js b/js/src/jit-test/tests/collections/Map-iterator-remove-6.js
new file mode 100644
index 0000000000..9fc6f1e56e
--- /dev/null
+++ b/js/src/jit-test/tests/collections/Map-iterator-remove-6.js
@@ -0,0 +1,21 @@
+// Removing many Map entries does not cause a live iterator to skip any of the
+// entries that were not removed. (Compacting a Map must not be observable to
+// script.)
+
+load(libdir + "iteration.js");
+
+var map = new Map();
+for (var i = 0; i < 32; i++)
+    map.set(i, i);
+var iter = map[Symbol.iterator]();
+assertIteratorNext(iter, [0, 0]);
+for (var i = 0; i < 30; i++)
+    map.delete(i);
+assertEq(map.size, 2);
+for (var i = 32; i < 100; i++)
+    map.set(i, i);  // eventually triggers compaction
+
+for (var i = 30; i < 100; i++)
+    assertIteratorNext(iter, [i, i]);
+
+assertIteratorDone(iter, undefined);