Fix mangling of property names which overwrite unmangleable properties

Fixes #747.

1 files changed, 14 insertions, 12 deletions

diff --git a/lib/propmangle.js b/lib/propmangle.js
index 086709e6..840bda91 100644
--- a/lib/propmangle.js
+++ b/lib/propmangle.js
@@ -83,6 +83,7 @@ function mangle_properties(ast, options) {
     var regex = options.regex;
 
     var names_to_mangle = [];
+    var unmangleable = [];
 
     // step 1: find candidates to mangle
     ast.walk(new TreeWalker(function(node){
@@ -108,20 +109,14 @@ function mangle_properties(ast, options) {
     // step 2: transform the tree, renaming properties
     return ast.transform(new TreeTransformer(function(node){
         if (node instanceof AST_ObjectKeyVal) {
-            if (should_mangle(node.key)) {
-                node.key = mangle(node.key);
-            }
+            node.key = mangle(node.key);
         }
         else if (node instanceof AST_ObjectProperty) {
             // setter or getter
-            if (should_mangle(node.key.name)) {
-                node.key.name = mangle(node.key.name);
-            }
+            node.key.name = mangle(node.key.name);
         }
         else if (node instanceof AST_Dot) {
-            if (should_mangle(node.property)) {
-                node.property = mangle(node.property);
-            }
+            node.property = mangle(node.property);
         }
         else if (node instanceof AST_Sub) {
             node.property = mangleStrings(node.property);
@@ -143,6 +138,7 @@ function mangle_properties(ast, options) {
     // only function declarations after this line
 
     function can_mangle(name) {
+        if (unmangleable.indexOf(name) >= 0) return false;
         if (reserved.indexOf(name) >= 0) return false;
         if (options.only_cache) {
             return cache.props.has(name);
@@ -161,9 +157,17 @@ function mangle_properties(ast, options) {
     function add(name) {
         if (can_mangle(name))
             push_uniq(names_to_mangle, name);
+
+        if (!should_mangle(name)) {
+            push_uniq(unmangleable, name);
+        }
     }
 
     function mangle(name) {
+        if (!should_mangle(name)) {
+            return name;
+        }
+
         var mangled = cache.props.get(name);
         if (!mangled) {
             do {
@@ -206,9 +210,7 @@ function mangle_properties(ast, options) {
                 node.cdr = mangleStrings(node.cdr);
             }
             else if (node instanceof AST_String) {
-                if (should_mangle(node.value)) {
-                    node.value = mangle(node.value);
-                }
+                node.value = mangle(node.value);
             }
             else if (node instanceof AST_Conditional) {
                 node.consequent = mangleStrings(node.consequent);