fix crash in unsafe replacement of undefined

remove extraneous call to AST_SymbolRef.reference()

closes #1443

1 files changed, 1 insertions, 3 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 04aa1072..a15206e8 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -2721,13 +2721,11 @@ merge(Compressor.prototype, {
             var scope = compressor.find_parent(AST_Scope);
             var undef = scope.find_variable("undefined");
             if (undef) {
-                var ref = make_node(AST_SymbolRef, self, {
+                return make_node(AST_SymbolRef, self, {
                     name   : "undefined",
                     scope  : scope,
                     thedef : undef
                 });
-                ref.reference();
-                return ref;
             }
         }
         return self;