fix `AST_Scope.clone()` (#2803)

fixes #2799

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/ast.js b/lib/ast.js
index 4e41659c..19f6bfb5 100644
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -308,6 +308,13 @@ var AST_Scope = DEFNODE("Scope", "variables functions uses_with uses_eval parent
         enclosed: "[SymbolDef*/S] a list of all symbol definitions that are accessed from this scope or any subscopes",
         cname: "[integer/S] current index for mangling variables (used internally by the mangler)",
     },
+    clone: function(deep) {
+        var node = this._clone(deep);
+        if (this.variables) node.variables = this.variables.clone();
+        if (this.functions) node.functions = this.functions.clone();
+        if (this.enclosed) node.enclosed = this.enclosed.slice();
+        return node;
+    }
 }, AST_Block);
 
 var AST_Toplevel = DEFNODE("Toplevel", "globals", {