don't duplicate argument names

diff --git a/lib/compress.js b/lib/compress.js
index 3d2f540..d8def86 100644 (file)
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -521,7 +521,10 @@ function Compressor(options, false_by_default) {
             if (vars_found > 0) {
                 if (self instanceof AST_Lambda && !self.uses_arguments) {
                     for (var i in vars) if (HOP(vars, i)) {
-                        self.argnames.push(vars[i].name);
+                        var sym = vars[i].name;
+                        if (!find_if(function(arg){ return arg.name == sym.name }, self.argnames)) {
+                            self.argnames.push(sym);
+                        }
                     }
                 } else {
                     var node = make_node(AST_Var, self, {