use a Dictionary object instead of plain object for hashes

to mitigate the `__proto__` issue

related to #30

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 5ceef200..fe212b42 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1026,7 +1026,7 @@ merge(Compressor.prototype, {
         if (hoist_funs || hoist_vars) {
             var dirs = [];
             var hoisted = [];
-            var vars = {}, vars_found = 0, var_decl = 0;
+            var vars = new Dictionary(), vars_found = 0, var_decl = 0;
             // let's count var_decl first, we seem to waste a lot of
             // space if we hoist `var` when there's only one.
             self.walk(new TreeWalker(function(node){
@@ -1051,7 +1051,7 @@ merge(Compressor.prototype, {
                         }
                         if (node instanceof AST_Var && hoist_vars) {
                             node.definitions.forEach(function(def){
-                                vars[def.name.name] = def;
+                                vars.set(def.name.name, def);
                                 ++vars_found;
                             });
                             var seq = node.to_assignments();
@@ -1075,8 +1075,8 @@ merge(Compressor.prototype, {
             );
             self = self.transform(tt);
             if (vars_found > 0) hoisted.unshift(make_node(AST_Var, self, {
-                definitions: Object.keys(vars).map(function(name){
-                    var def = vars[name].clone();
+                definitions: vars.map(function(def){
+                    def = def.clone();
                     def.value = null;
                     return def;
                 })