diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/debug/Frame-eval-14.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/debug/Frame-eval-14.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,25 @@
+// Test the corner case of accessing an unaliased variable of a block
+// while the block is not live.
+
+var g = newGlobal();
+g.eval("function h() { debugger }");
+g.eval("function f() { let (x = 1, y) { (function() { y = 0 })(); h() } }");
+g.eval("var surprise = null");
+
+var dbg = new Debugger(g);
+dbg.onDebuggerStatement = function(hFrame) {
+    var fFrame = hFrame.older;
+    assertEq(fFrame.environment.getVariable('x'), 1);
+    assertEq(fFrame.environment.getVariable('y'), 0);
+    fFrame.eval("surprise = function() { return ++x }");
+    assertEq(g.surprise(), 2);
+}
+g.f();
+assertEq(g.surprise !== null, true);
+
+// Either succeed or throw an error about 'x' not being live
+try {
+    assertEq(g.surprise(), 3);
+} catch (e) {
+    assertEq(e+'', 'Error: x is not live');
+}