From d757202b74969495d662d58b4d7da9c4c12e8a5d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A1bio=20Santos?= <fabiosantosart@gmail.com>
Date: Fri, 14 Aug 2015 02:00:31 +0100
Subject: [PATCH] Do not mangle a name if it is in a destructuring vardef.

---
 lib/scope.js | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/lib/scope.js b/lib/scope.js
index 8b60ce8f..2388fb52 100644
--- a/lib/scope.js
+++ b/lib/scope.js
@@ -98,7 +98,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
     var defun = null;
     var last_var_had_const_pragma = false;
     var nesting = 0;
-    var object_destructuring_arg = false;
+    var in_destructuring = null;
     var tw = new TreeWalker(function(node, descend){
         if (options.screw_ie8 && node instanceof AST_Catch) {
             var save_scope = scope;
@@ -110,9 +110,9 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             return true;
         }
         if (node instanceof AST_Destructuring && node.is_array === false) {
-            object_destructuring_arg = true;  // These don't nest
+            in_destructuring = node;  // These don't nest
             descend();
-            object_destructuring_arg = false;
+            in_destructuring = null;
             return true;
         }
         if (node instanceof AST_Scope) {
@@ -151,7 +151,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             node.references = [];
         }
         if (node instanceof AST_SymbolFunarg) {
-            node.object_destructuring_arg = object_destructuring_arg;
+            node.object_destructuring_arg = !!in_destructuring;
             defun.def_variable(node);
         }
         if (node instanceof AST_SymbolLambda) {
@@ -171,7 +171,8 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
         else if (node instanceof AST_SymbolVar
                  || node instanceof AST_SymbolConst) {
             var def = defun.def_variable(node);
-            def.constant = node instanceof AST_SymbolConst || last_var_had_const_pragma;
+            def.constant = node instanceof AST_SymbolConst;
+            def.destructuring = in_destructuring;
             def.init = tw.parent().value;
         }
         else if (node instanceof AST_SymbolCatch) {
@@ -458,7 +459,10 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
         }
     });
     this.walk(tw);
-    to_mangle.forEach(function(def){ def.mangle(options) });
+    to_mangle.forEach(function(def){
+        if (def.destructuring && !def.destructuring.is_array) return;
+        def.mangle(options);
+    });
 
     if (options.cache) {
         options.cache.cname = this.cname;