no base54.reset()

slightly less improved gzip results

lib/scope.js

@@ -458,9 +458,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     this.walk(tw);
     to_mangle.forEach(function(def){ def.mangle(options) });
 
-    if (options.group_voids) {
+    if (!options.group_voids) return;
-        base54.reset();
-        base54.sort();
     if (options.toplevel) this.group_voids(options);
     else this.walk(new TreeWalker(function(node) {
         if (node instanceof AST_Scope && !(node instanceof AST_Toplevel)) {
@@ -468,7 +466,6 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
             return true;
         }
     }));
-    }
 
     function collect(symbol) {
         if (!member(symbol.name, options.reserved)) {
@@ -477,11 +474,11 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
     }
 });
 
-AST_Scope.DEFMETHOD("find_colliding_names", function(options, all) {
+AST_Toplevel.DEFMETHOD("find_colliding_names", function(options) {
     var cache = options.cache && options.cache.props;
     var avoid = Object.create(null);
     options.reserved.forEach(to_avoid);
-    if (this.globals) this.globals.each(add_def);
+    this.globals.each(add_def);
     this.walk(new TreeWalker(function(node) {
         if (node instanceof AST_Scope) node.variables.each(add_def);
         if (node instanceof AST_SymbolCatch) add_def(node.definition());
@@ -493,9 +490,9 @@ AST_Scope.DEFMETHOD("find_colliding_names", function(options, all) {
     }
 
     function add_def(def) {
-        var name = def.mangled_name || def.name;
+        var name = def.name;
         if (def.global && cache && cache.has(name)) name = cache.get(name);
-        else if (!all && !def.unmangleable(options)) return;
+        else if (!def.unmangleable(options)) return;
         to_avoid(name);
     }
 });
@@ -536,27 +533,38 @@ AST_Toplevel.DEFMETHOD("expand_names", function(options) {
 });
 
 AST_Scope.DEFMETHOD("group_voids", function(options) {
-    var avoid = this.find_colliding_names(options, true);
+    var self = this, enclosed = [];
-    var cname = 0;
+    var scopes = [], count = 0;
-    var name;
+    self.walk(new TreeWalker(function(node, descend) {
-    do {
+        if (node instanceof AST_Scope && node !== self) {
-        name = base54(cname++);
+            scopes.unshift(node);
-    } while (avoid[name] || !is_identifier(name));
+            descend();
-    var count = 0;
+            if (scopes[0] === node) scopes.shift();
-    this.transform(new TreeTransformer(function(node) {
+            return true;
-        if (node instanceof AST_Undefined
+        }
-            || node instanceof AST_UnaryPrefix
+        if (count > 0 && scopes.length == 0) return;
-                && node.operator == "void"
+        if (is_undefined(node)) {
-                && node.expression.is_constant()) {
             count++;
-            return new AST_SymbolRef({
+            var scope;
+            while (scope = scopes.shift()) {
+                scope.enclosed.forEach(function(def) {
+                    push_uniq(enclosed, def);
+                });
+            }
+        }
+    }));
+    if (count < 1) return;
+    var save = self.enclosed;
+    self.enclosed = enclosed;
+    var name = next_mangled(self, options);
+    self.enclosed = save;
+    this.transform(new TreeTransformer(function(node) {
+        if (is_undefined(node)) return new AST_SymbolRef({
             name: name,
             start: node.start,
             end: node.end
         });
-        }
     }));
-    if (count) {
     for (var i = 0, len = this.body.length; i < len; i++) {
         var stat = this.body[i];
         if (stat instanceof AST_Var) {
@@ -569,6 +577,12 @@ AST_Scope.DEFMETHOD("group_voids", function(options) {
         start: this.start,
         end: this.end
     }));
+
+    function is_undefined(node) {
+        return node instanceof AST_Undefined
+            || node instanceof AST_UnaryPrefix
+                && node.operator == "void"
+                && node.expression.is_constant();
     }
 
     function make_var_def(node) {

test/compress/group_voids.js

@@ -26,13 +26,13 @@ group_voids: {
             console.log(void 0);
             for (var a = 4;;);
             var b = 4;
-            function f5() {
+            function g() {
                 var c = 5;
                 var d = 5;
                 console.log(void 0);
             }
         }
-        function f6() {
+        function f5() {
             try {
                 var a = 6;
                 console.log(void 0);
@@ -47,35 +47,35 @@ group_voids: {
         if (void 0 === b)
             c = void 0;
         function f1() {
-            var o = 1, a;
+            var o = 1, n;
-            console.log(a);
+            console.log(n);
         }
         function f2(o) {
-            var n = 2, a;
+            var n = 2, v;
-            console.log(a);
+            console.log(v);
         }
         function f3() {
-            var o = 3, a;
+            var o = 3, n;
-            console.log(a);
+            console.log(n);
         }
         function f4() {
-            console.log(a);
+            console.log(i);
             for(var o = 4;;);
-            var n = 4, a;
+            var n = 4, i;
             function v() {
                 var o = 5;
                 var n = 5;
-                console.log(a);
+                console.log(i);
             }
         }
-        function f6() {
+        function f5() {
             try {
                 var o = 6;
-                console.log(a);
+                console.log(n);
             } catch (o) {
-                console.log(a);
+                console.log(n);
             }
-            var a;
+            var n;
         }
     }
 }
@@ -108,13 +108,13 @@ group_voids_toplevel: {
             console.log(void 0);
             for (var a = 4;;);
             var b = 4;
-            function f5() {
+            function g() {
                 var c = 5;
                 var d = 5;
                 console.log(void 0);
             }
         }
-        function f6() {
+        function f5() {
             try {
                 var a = 6;
                 console.log(void 0);
@@ -168,8 +168,7 @@ group_voids_catch: {
         group_voids: true,
     }
     input: {
-        f();
+        (function() {
-        function f() {
             var a = 1;
             console.log(void 0);
             try {
@@ -177,19 +176,18 @@ group_voids_catch: {
             } catch (undefined) {
                 console.log(void 0);
             }
-        }
+        })();
     }
     expect: {
-        f();
+        (function() {
-        function f() {
+            var o = 1, c;
-            var o = 1, a;
+            console.log(c);
-            console.log(a);
             try {
                 throw "FAIL";
             } catch (o) {
-                console.log(a);
+                console.log(c);
-            }
             }
+        })();
     }
     expect_stdout: [
         "undefined",