From c0c6a44f0458a1d0e6f8b1148d93340c18af2b4c Mon Sep 17 00:00:00 2001
From: Luke Wagner <luke@mozilla.com>
Date: Fri, 25 May 2012 11:44:38 +0200
Subject: [PATCH] Bug 756918 - Fix aliased, empty destructuring let (r=waldo)

---
 js/src/frontend/BytecodeEmitter.cpp          | 1 +
 js/src/jit-test/tests/basic/testBug756918.js | 6 ++++++
 2 files changed, 7 insertions(+)
 create mode 100644 js/src/jit-test/tests/basic/testBug756918.js

diff --git a/js/src/frontend/BytecodeEmitter.cpp b/js/src/frontend/BytecodeEmitter.cpp
index c9a4b6e5561..c06a10d25e4 100644
--- a/js/src/frontend/BytecodeEmitter.cpp
+++ b/js/src/frontend/BytecodeEmitter.cpp
@@ -1033,6 +1033,7 @@ EmitEnterBlock(JSContext *cx, BytecodeEmitter *bce, ParseNode *pn, JSOp op)
         /* Beware the empty destructuring dummy. */
         if (!dn) {
             JS_ASSERT(i + 1 <= blockObj->slotCount());
+            blockObj->setAliased(i, bce->sc->bindingsAccessedDynamically());
             continue;
         }
 
diff --git a/js/src/jit-test/tests/basic/testBug756918.js b/js/src/jit-test/tests/basic/testBug756918.js
new file mode 100644
index 00000000000..2787b38813b
--- /dev/null
+++ b/js/src/jit-test/tests/basic/testBug756918.js
@@ -0,0 +1,6 @@
+// |jit-test| error:Error
+
+with({})
+  let([] = []) {
+    eval("throw new Error()");
+  }