diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug610592.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug610592.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,29 @@
+
+/* Don't confuse JIT code by making slow arrays that use inline slots inconsistently. */
+
+function foo(a)
+{
+  assertEq(a.x, 5);
+}
+
+function bar()
+{
+  for (var i = 0; i < 50; i++) {
+    var a = [];
+    a[i] = 0;
+    delete a[i];
+    a.x = 5;
+    foo(a);
+  }
+
+  var b = [1,,2,,3,,4,,5];
+  assertEq(b.toString(), "1,,2,,3,,4,,5");
+  b.x = 0;
+  assertEq(b.toString(), "1,,2,,3,,4,,5");
+  delete b.x;
+  delete b[8];
+  delete b[6];
+  delete b[4];
+  assertEq(b.toString(), "1,,2,,,,,,");
+}
+bar();