1 files changed, 31 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/collections/Map-iterator-remove-4.js b/js/src/jit-test/tests/collections/Map-iterator-remove-4.js
new file mode 100644
index 0000000000..7739000137
--- /dev/null
+++ b/js/src/jit-test/tests/collections/Map-iterator-remove-4.js
@@ -0,0 +1,31 @@
+// Multiple live iterators on the same Map can cope with removing entries.
+
+load(libdir + "iteration.js");
+
+// Make a map.
+var map = new Map();
+var SIZE = 7;
+for (var j = 0; j < SIZE; j++)
+    map.set(j, j);
+
+// Make lots of iterators pointing to entry 2 of the map.
+var NITERS = 5;
+var iters = [];
+for (var i = 0; i < NITERS; i++) {
+    var iter = map[Symbol.iterator]();
+    assertIteratorNext(iter, [0, 0]);
+    assertIteratorNext(iter, [1, 1]);
+    iters[i] = iter;
+}
+
+// Remove half of the map entries.
+for (var j = 0; j < SIZE; j += 2)
+    map.delete(j);
+
+// Make sure all the iterators still work.
+for (var i = 0; i < NITERS; i++) {
+    var iter = iters[i];
+    for (var j = 3; j < SIZE; j += 2)
+        assertIteratorNext(iter, [j, j]);
+    assertIteratorDone(iter, undefined);
+}