From 25742678cc510034e599bfc4fcf811bca19d3b2f Mon Sep 17 00:00:00 2001
From: Morgan Phillips <winter2718@gmail.com>
Date: Tue, 7 Jun 2016 14:12:19 -0700
Subject: [PATCH] Bug 1255167 - Default destructuring arguments should show up
 as lexical dependencies; r=jorendorff

--HG--
extra : rebase_source : 88d9870638eb5565410a5acc23c19f119e56a117
---
 js/src/frontend/Parser.cpp                               | 5 +++++
 .../ecma_6/Object/destructuring-shorthand-defaults.js    | 9 +++++++++
 2 files changed, 14 insertions(+)

diff --git a/js/src/frontend/Parser.cpp b/js/src/frontend/Parser.cpp
index 1361b6a96ec0..090d3a029eee 100644
--- a/js/src/frontend/Parser.cpp
+++ b/js/src/frontend/Parser.cpp
@@ -9352,7 +9352,12 @@ Parser<ParseHandler>::objectLiteral(YieldHandling yieldHandling, PossibleError*
                 return null();
 
             tokenStream.consumeKnownToken(TOK_ASSIGN);
+            bool saved = pc->inDeclDestructuring;
+            // Setting `inDeclDestructuring` to false allows name use to be noted
+            // in `identifierName` See Bug: 1255167.
+            pc->inDeclDestructuring = false;
             Node rhs = assignExpr(InAllowed, yieldHandling, TripledotProhibited);
+            pc->inDeclDestructuring = saved;
             if (!rhs)
                 return null();
 
diff --git a/js/src/tests/ecma_6/Object/destructuring-shorthand-defaults.js b/js/src/tests/ecma_6/Object/destructuring-shorthand-defaults.js
index 09adc7719977..879ff33f2954 100644
--- a/js/src/tests/ecma_6/Object/destructuring-shorthand-defaults.js
+++ b/js/src/tests/ecma_6/Object/destructuring-shorthand-defaults.js
@@ -123,5 +123,14 @@ assertEq((({a = 0} = {}) => a)({a: 1}), 1);
     assertEq(j, 2);
 }
 
+// Default destructuring values, which are variables, should be defined
+// within closures (Bug 1255167).
+{
+    let f = function(a){
+        return (function({aa = a}){ return aa; })({});
+    };
+    assertEq(f(9999), 9999);
+}
+
 if (typeof reportCompare == "function")
     reportCompare(true, true);