diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/ion/bug798823.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/ion/bug798823.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,37 @@
+function g() {
+  switch (0) {
+  default:
+    w = newGlobal('');
+  }
+  return function(f, code) {
+    try {
+      evalcx(code, w)
+    } catch (e) {}
+  }
+}
+
+function f(code) {
+  h(Function(code), code);
+}
+h = g()
+f("\
+    x = [];\
+    y = new Set;\
+    z = [];\
+    Object.defineProperty(x, 5, {\
+        get: (function(j) {}),\
+    });\
+    Object.defineProperty(z, 3, {});\
+    z[9] = 1;\
+    x.shift();\
+");
+f("\
+    z.every(function() {\
+        x.filter(function(j) {\
+            if (j) {} else {\
+                y.add()\
+            }\
+        });\
+        return 2\
+    })\
+");