1 files changed, 15 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/basic/densify-elements.js b/js/src/jit-test/tests/basic/densify-elements.js
new file mode 100644
index 0000000000..f2944c0e55
--- /dev/null
+++ b/js/src/jit-test/tests/basic/densify-elements.js
@@ -0,0 +1,15 @@
+function f(o) {
+    for (var i = 1; i <= 5; i += 4) {
+        var start = i * 4000;
+        var end = (start * 1.4)|0;
+        for (var j = end; j > start; j--) {
+            o[j] = j;
+        }
+    }
+    assertEq(Object.keys(o).length, 9600);
+}
+f({});
+f([]);
+let obj = newObjectWithManyReservedSlots();
+f(obj);
+checkObjectWithManyReservedSlots(obj);