v3.11.2

fixes #4188

bin/uglifyjs

@@ -342,7 +342,18 @@ function run() {
         }
         fatal(ex);
     } else if (output == "ast") {
-        if (!options.compress && !options.mangle) result.ast.figure_out_scope({});
+        if (!options.compress && !options.mangle) {
+            var toplevel = result.ast;
+            if (!(toplevel instanceof UglifyJS.AST_Toplevel)) {
+                if (!(toplevel instanceof UglifyJS.AST_Statement)) toplevel = new UglifyJS.AST_SimpleStatement({
+                    body: toplevel,
+                });
+                toplevel = new UglifyJS.AST_Toplevel({
+                    body: [ toplevel ],
+                });
+            }
+            toplevel.figure_out_scope({});
+        }
         print(JSON.stringify(result.ast, function(key, value) {
             if (value) switch (key) {
               case "thedef":

lib/ast.js

@@ -251,9 +251,38 @@ var AST_Block = DEFNODE("Block", "body", {
     },
 }, AST_Statement);
 
+var AST_BlockScope = DEFNODE("BlockScope", "cname enclosed functions make_def parent_scope variables", {
+    $documentation: "Base class for all statements introducing a lexical scope",
+    $propdoc: {
+        cname: "[integer/S] current index for mangling variables (used internally by the mangler)",
+        enclosed: "[SymbolDef*/S] a list of all symbol definitions that are accessed from this scope or any subscopes",
+        functions: "[Object/S] like `variables`, but only lists function declarations",
+        parent_scope: "[AST_Scope?/S] link to the parent scope",
+        variables: "[Object/S] a map of name -> SymbolDef for all variables/functions defined in this scope",
+    },
+    clone: function(deep) {
+        var node = this._clone(deep);
+        if (this.enclosed) node.enclosed = this.enclosed.slice();
+        if (this.functions) node.functions = this.functions.clone();
+        if (this.variables) node.variables = this.variables.clone();
+        return node;
+    },
+    pinned: function() {
+        return this.resolve().pinned();
+    },
+    resolve: function() {
+        return this.parent_scope.resolve();
+    },
+    _validate: function() {
+        if (this.parent_scope == null) return;
+        if (!(this.parent_scope instanceof AST_BlockScope)) throw new Error("parent_scope must be AST_BlockScope");
+        if (!(this.resolve() instanceof AST_Scope)) throw new Error("must be contained within AST_Scope");
+    },
+}, AST_Block);
+
 var AST_BlockStatement = DEFNODE("BlockStatement", null, {
     $documentation: "A block statement",
-}, AST_Block);
+}, AST_BlockScope);
 
 var AST_EmptyStatement = DEFNODE("EmptyStatement", null, {
     $documentation: "The empty statement (empty block or simply a semicolon)"
@@ -412,33 +441,17 @@ var AST_With = DEFNODE("With", "expression", {
 
 /* -----[ scope and functions ]----- */
 
-var AST_Scope = DEFNODE("Scope", "cname enclosed uses_eval uses_with parent_scope functions variables make_def", {
+var AST_Scope = DEFNODE("Scope", "uses_eval uses_with", {
     $documentation: "Base class for all statements introducing a lexical scope",
     $propdoc: {
-        cname: "[integer/S] current index for mangling variables (used internally by the mangler)",
-        enclosed: "[SymbolDef*/S] a list of all symbol definitions that are accessed from this scope or any subscopes",
         uses_eval: "[boolean/S] tells whether this scope contains a direct call to the global `eval`",
         uses_with: "[boolean/S] tells whether this scope uses the `with` statement",
-        parent_scope: "[AST_Scope?/S] link to the parent scope",
-        functions: "[Object/S] like `variables`, but only lists function declarations",
-        variables: "[Object/S] a map of name -> SymbolDef for all variables/functions defined in this scope",
-    },
-    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;
     },
     pinned: function() {
         return this.uses_eval || this.uses_with;
     },
-    _validate: function() {
+    resolve: return_this,
-        if (this.parent_scope != null) {
+}, AST_BlockScope);
-            if (!(this.parent_scope instanceof AST_Scope)) throw new Error("parent_scope must be AST_Scope");
-        }
-    },
-}, AST_Block);
 
 var AST_Toplevel = DEFNODE("Toplevel", "globals", {
     $documentation: "The toplevel scope",
@@ -686,28 +699,30 @@ var AST_Try = DEFNODE("Try", "bcatch bfinally", {
             if (!(this.bfinally instanceof AST_Finally)) throw new Error("bfinally must be AST_Finally");
         }
     },
-}, AST_Block);
+}, AST_BlockScope);
 
 var AST_Catch = DEFNODE("Catch", "argname", {
     $documentation: "A `catch` node; only makes sense as part of a `try` statement",
     $propdoc: {
-        argname: "[AST_SymbolCatch] symbol for the exception"
+        argname: "[AST_SymbolCatch?] symbol for the exception, or null if not present",
     },
     walk: function(visitor) {
         var node = this;
         visitor.visit(node, function() {
-            node.argname.walk(visitor);
+            if (node.argname) node.argname.walk(visitor);
             walk_body(node, visitor);
         });
     },
     _validate: function() {
-        if (!(this.argname instanceof AST_SymbolCatch)) throw new Error("argname must be AST_SymbolCatch");
+        if (this.argname != null) {
+            if (!(this.argname instanceof AST_SymbolCatch)) throw new Error("argname must be AST_SymbolCatch");
+        }
     },
-}, AST_Block);
+}, AST_BlockScope);
 
 var AST_Finally = DEFNODE("Finally", null, {
     $documentation: "A `finally` node; only makes sense as part of a `try` statement"
-}, AST_Block);
+}, AST_BlockScope);
 
 /* -----[ VAR ]----- */
 

lib/compress.js

@@ -354,6 +354,13 @@ merge(Compressor.prototype, {
         return orig.length == 1 && orig[0] instanceof AST_SymbolFunarg;
     }
 
+    function cross_scope(def, sym) {
+        do {
+            if (def === sym) return false;
+            if (sym instanceof AST_Scope) return true;
+        } while (sym = sym.parent_scope);
+    }
+
     (function(def) {
         def(AST_Node, noop);
 
@@ -368,10 +375,10 @@ merge(Compressor.prototype, {
                 && !(def.init instanceof AST_Function && def.init !== def.scope)
                 && def.init;
             if (def.fixed instanceof AST_Defun && !all(def.references, function(ref) {
-                var scope = ref.scope;
+                var scope = ref.scope.resolve();
                 do {
                     if (def.scope === scope) return true;
-                } while (scope instanceof AST_Function && (scope = scope.parent_scope));
+                } while (scope instanceof AST_Function && (scope = scope.parent_scope.resolve()));
             })) {
                 tw.defun_ids[def.id] = false;
             }
@@ -506,6 +513,7 @@ merge(Compressor.prototype, {
         function ref_once(compressor, def) {
             return compressor.option("unused")
                 && !def.scope.pinned()
+                && def.single_use !== false
                 && def.references.length - def.recursive_refs == 1;
         }
 
@@ -700,7 +708,7 @@ merge(Compressor.prototype, {
             tw.in_loop = this;
             push(tw);
             this.body.walk(tw);
-            if (has_break_or_continue(this, tw.parent())) {
+            if (has_loop_control(this, tw.parent())) {
                 pop(tw);
                 push(tw);
             }
@@ -717,7 +725,7 @@ merge(Compressor.prototype, {
             if (this.condition) this.condition.walk(tw);
             this.body.walk(tw);
             if (this.step) {
-                if (has_break_or_continue(this, tw.parent())) {
+                if (has_loop_control(this, tw.parent())) {
                     pop(tw);
                     push(tw);
                 }
@@ -840,11 +848,13 @@ merge(Compressor.prototype, {
                 && d.orig[0] instanceof AST_SymbolDefun) {
                 tw.loop_ids[d.id] = tw.in_loop;
             }
-            var value;
+            if (d.fixed === false) {
-            if (d.fixed === undefined || !safe_to_read(tw, d)) {
+                var redef = d.redefined();
+                if (redef && cross_scope(d.scope, this.scope)) redef.single_use = false;
+            } else if (d.fixed === undefined || !safe_to_read(tw, d)) {
                 d.fixed = false;
             } else if (d.fixed) {
-                value = this.fixed_value();
+                var value = this.fixed_value();
                 var recursive = recursive_ref(tw, d);
                 if (recursive) {
                     d.recursive_refs++;
@@ -854,7 +864,7 @@ merge(Compressor.prototype, {
                             && !value.pinned()
                             && (!d.in_loop || tw.parent() instanceof AST_Call)
                         || !d.in_loop
-                            && d.scope === this.scope
+                            && d.scope === this.scope.resolve()
                             && value.is_constant_expression();
                 } else {
                     d.single_use = false;
@@ -1018,6 +1028,13 @@ merge(Compressor.prototype, {
         return sym instanceof AST_SymbolLambda && def.scope.name === sym;
     });
 
+    function find_scope(compressor) {
+        var level = 0, node;
+        while (node = compressor.parent(level++)) {
+            if (node.variables) return node;
+        }
+    }
+
     function is_lhs_read_only(lhs, compressor) {
         if (lhs instanceof AST_This) return true;
         if (lhs instanceof AST_SymbolRef) {
@@ -1037,18 +1054,6 @@ merge(Compressor.prototype, {
         return false;
     }
 
-    function find_variable(compressor, name) {
-        var scope, i = 0;
-        while (scope = compressor.parent(i++)) {
-            if (scope instanceof AST_Scope) break;
-            if (scope instanceof AST_Catch) {
-                scope = scope.argname.definition().scope;
-                break;
-            }
-        }
-        return scope.find_variable(name);
-    }
-
     function make_node(ctor, orig, props) {
         if (!props) props = {};
         if (orig) {
@@ -1192,6 +1197,16 @@ merge(Compressor.prototype, {
             || node instanceof AST_Undefined;
     }
 
+    function declarations_only(node) {
+        return all(node.definitions, function(var_def) {
+            return !var_def.value;
+        });
+    }
+
+    function is_declaration(stat) {
+        return stat instanceof AST_Defun || stat instanceof AST_Var && declarations_only(stat);
+    }
+
     function tighten_body(statements, compressor) {
         var in_loop, in_try, scope;
         find_loop_scope_try();
@@ -2150,7 +2165,9 @@ merge(Compressor.prototype, {
         function handle_if_return(statements, compressor) {
             var self = compressor.self();
             var parent = compressor.parent();
-            var in_lambda = self instanceof AST_Lambda;
+            var in_lambda = last_of(function(node) {
+                return node instanceof AST_Lambda;
+            });
             var in_iife = in_lambda && parent && parent.TYPE == "Call";
             var multiple_if_returns = has_multiple_if_returns(statements);
             for (var i = statements.length; --i >= 0;) {
@@ -2253,7 +2270,7 @@ merge(Compressor.prototype, {
                     }
                     //---
                     // if (foo()) return x; return y; => return foo() ? x : y;
-                    if ((in_bool || value) && !stat.alternative && next instanceof AST_Return) {
+                    if (!stat.alternative && next instanceof AST_Return) {
                         CHANGED = true;
                         stat = stat.clone();
                         stat.alternative = next;
@@ -2323,14 +2340,21 @@ merge(Compressor.prototype, {
                 return true;
             }
 
-            function match_target(target) {
+            function last_of(predicate) {
                 var block = self, stat, level = 0;
                 do {
                     do {
-                        if (block === target) return true;
+                        if (predicate(block)) return true;
                         block = compressor.parent(level++);
                     } while (block instanceof AST_If && (stat = block));
-                } while (block instanceof AST_BlockStatement && is_last_statement(block.body, stat));
+                } while ((block instanceof AST_BlockStatement || block instanceof AST_Scope)
+                    && is_last_statement(block.body, stat));
+            }
+
+            function match_target(target) {
+                return last_of(function(node) {
+                    return node === target;
+                });
             }
 
             function can_merge_flow(ab) {
@@ -2410,16 +2434,6 @@ merge(Compressor.prototype, {
             });
         }
 
-        function declarations_only(node) {
-            return all(node.definitions, function(var_def) {
-                return !var_def.value;
-            });
-        }
-
-        function is_declaration(stat) {
-            return stat instanceof AST_Defun || stat instanceof AST_Var && declarations_only(stat);
-        }
-
         function sequencesize(statements, compressor) {
             if (statements.length < 2) return;
             var seq = [], n = 0;
@@ -2588,7 +2602,7 @@ merge(Compressor.prototype, {
                 var lhs = expr.left;
                 if (!(lhs instanceof AST_SymbolRef)) break;
                 if (is_undeclared_ref(lhs)) break;
-                if (lhs.scope !== scope) break;
+                if (lhs.scope.resolve() !== scope) break;
                 var def = lhs.definition();
                 if (def.scope !== scope) break;
                 if (def.orig.length > def.eliminated + 1) break;
@@ -2914,6 +2928,9 @@ merge(Compressor.prototype, {
             this._dot_throw = return_false;
             return false;
         });
+        def(AST_This, function(compressor) {
+            return is_strict(compressor) && !this.scope.new;
+        });
         def(AST_UnaryPrefix, function() {
             return this.operator == "void";
         });
@@ -3947,7 +3964,15 @@ merge(Compressor.prototype, {
         def(AST_Array, function(compressor) {
             return any(this.elements, compressor);
         });
-        def(AST_Assign, return_true);
+        def(AST_Assign, function(compressor) {
+            var lhs = this.left;
+            if (!(lhs instanceof AST_PropAccess)) return true;
+            var node = lhs.expression;
+            return !(node instanceof AST_This)
+                || !node.scope.new
+                || lhs instanceof AST_Sub && lhs.property.has_side_effects(compressor)
+                || this.right.has_side_effects(compressor);
+        });
         def(AST_Binary, function(compressor) {
             return this.left.has_side_effects(compressor)
                 || this.right.has_side_effects(compressor)
@@ -4168,13 +4193,7 @@ merge(Compressor.prototype, {
             var scopes = [];
             self.walk(new TreeWalker(function(node, descend) {
                 if (!result) return true;
-                if (node instanceof AST_Catch) {
+                if (node instanceof AST_BlockScope) {
-                    scopes.push(node.argname.scope);
-                    descend();
-                    scopes.pop();
-                    return true;
-                }
-                if (node instanceof AST_Scope) {
                     if (node === self) return;
                     scopes.push(node);
                     descend();
@@ -4182,14 +4201,14 @@ merge(Compressor.prototype, {
                     return true;
                 }
                 if (node instanceof AST_SymbolRef) {
-                    if (self.inlined) {
+                    if (self.inlined || node.redef) {
                         result = false;
                         return true;
                     }
                     if (self.variables.has(node.name)) return true;
                     var def = node.definition();
                     if (member(def.scope, scopes)) return true;
-                    if (scope) {
+                    if (scope && !def.redefined()) {
                         var scope_def = scope.find_variable(node);
                         if (def.undeclared ? !scope_def : scope_def === def) {
                             result = "f";
@@ -4266,13 +4285,17 @@ merge(Compressor.prototype, {
         return self;
     });
 
+    function trim_block(stat) {
+        switch (stat.body.length) {
+          case 1: return stat.body[0];
+          case 0: return make_node(AST_EmptyStatement, stat);
+        }
+        return stat;
+    }
+
     OPT(AST_BlockStatement, function(self, compressor) {
         self.body = tighten_body(self.body, compressor);
-        switch (self.body.length) {
+        return trim_block(self);
-          case 1: return self.body[0];
-          case 0: return make_node(AST_EmptyStatement, self);
-        }
-        return self;
     });
 
     OPT(AST_Function, function(self, compressor) {
@@ -4415,7 +4438,12 @@ merge(Compressor.prototype, {
                 push();
                 segment.block = node;
                 if (node === self) root = segment;
-                if (node instanceof AST_Lambda && node.name) references[node.name.definition().id] = false;
+                if (node instanceof AST_Lambda) {
+                    if (node.name) references[node.name.definition().id] = false;
+                    if (node.uses_arguments && !tw.has_directive("use strict")) node.argnames.forEach(function(node) {
+                        references[node.definition().id] = false;
+                    });
+                }
                 descend();
                 pop();
                 return true;
@@ -4448,15 +4476,18 @@ merge(Compressor.prototype, {
                 push();
                 segment.block = node;
                 walk_body(node, tw);
-                if (node.bcatch) {
-                    var def = node.bcatch.argname.definition();
-                    references[def.id] = false;
-                    if (def = def.redefined()) references[def.id] = false;
-                    pop();
-                    push();
-                    walk_body(node.bcatch, tw);
-                }
                 pop();
+                if (node.bcatch) {
+                    if (node.bcatch.argname) {
+                        var def = node.bcatch.argname.definition();
+                        references[def.id] = false;
+                        if (def = def.redefined()) references[def.id] = false;
+                    }
+                    push();
+                    if (node.bfinally) segment.block = node.bcatch;
+                    walk_body(node.bcatch, tw);
+                    pop();
+                }
                 if (node.bfinally) node.bfinally.walk(tw);
                 return true;
             }
@@ -4482,6 +4513,7 @@ merge(Compressor.prototype, {
                 return true;
             }
         });
+        tw.directives = Object.create(compressor.directives);
         self.walk(tw);
         var merged = Object.create(null);
         while (first.length && last.length) {
@@ -4792,15 +4824,15 @@ merge(Compressor.prototype, {
                     for (var a = node.argnames, i = a.length; --i >= 0;) {
                         var sym = a[i];
                         var def = sym.definition();
-                        if (!(def.id in in_use_ids)) {
+                        if (def.id in in_use_ids) {
+                            trim = false;
+                            if (indexOf_assign(def, sym) < 0) sym.__unused = null;
+                        } else {
                             sym.__unused = true;
                             if (trim) {
                                 log(sym, "Dropping unused function argument {name}");
                                 a.pop();
                             }
-                        } else {
-                            trim = false;
-                            if (indexOf_assign(def, sym) < 0) sym.__unused = null;
                         }
                     }
                     fns_with_marked_args.push(node);
@@ -4853,8 +4885,8 @@ merge(Compressor.prototype, {
                                 && (old_def.name == def.name.name || all(old_def.references, function(ref) {
                                     return ref.scope.find_variable(def.name) === def.name.definition();
                                 })))
-                            && can_rename(def.value, def.name.name)
+                            && can_declare_defun()
-                            && (!compressor.has_directive("use strict") || parent instanceof AST_Scope)) {
+                            && can_rename(def.value, def.name.name)) {
                             AST_Node.warn("Declaring {name} as function [{file}:{line},{col}]", template(def.name));
                             var defun = make_node(AST_Defun, def, def.value);
                             defun.name = make_node(AST_SymbolDefun, def.name, def.name);
@@ -4910,6 +4942,13 @@ merge(Compressor.prototype, {
                         var def = fn.variables.get(name);
                         return !def || fn.name && def === fn.name.definition();
                     }
+
+                    function can_declare_defun() {
+                        if (compressor.has_directive("use strict")) return parent instanceof AST_Scope;
+                        return parent instanceof AST_Block
+                            || parent instanceof AST_For && parent.init === node
+                            || parent instanceof AST_If;
+                    }
                 });
                 switch (head.length) {
                   case 0:
@@ -5164,6 +5203,13 @@ merge(Compressor.prototype, {
                     in_use_ids[node_def.id] = true;
                     in_use.push(node_def);
                 }
+                if (cross_scope(node_def.scope, node.scope)) {
+                    var redef = node_def.redefined();
+                    if (redef && !(redef.id in in_use_ids)) {
+                        in_use_ids[redef.id] = true;
+                        in_use.push(redef);
+                    }
+                }
                 if (track_assigns(node_def, node)) add_assigns(node_def, node);
                 return true;
             }
@@ -5391,7 +5437,7 @@ merge(Compressor.prototype, {
         process_boolean_returns(this, compressor);
     });
 
-    AST_Scope.DEFMETHOD("var_names", function() {
+    AST_BlockScope.DEFMETHOD("var_names", function() {
         var var_names = this._var_names;
         if (!var_names) {
             this._var_names = var_names = Object.create(null);
@@ -5615,36 +5661,53 @@ merge(Compressor.prototype, {
             }
         });
         def(AST_Call, function(compressor, first_in_statement) {
-            if (!this.is_expr_pure(compressor)) {
+            var self = this;
-                var exp = this.expression;
+            if (self.is_expr_pure(compressor)) {
-                if (this.is_call_pure(compressor)) {
+                if (self.pure) AST_Node.warn("Dropping __PURE__ call [{file}:{line},{col}]", self.start);
-                    var exprs = this.args.slice();
+                var args = trim(self.args, compressor, first_in_statement);
-                    exprs.unshift(exp.expression);
+                return args && make_sequence(self, args);
-                    exprs = trim(exprs, compressor, first_in_statement);
-                    return exprs && make_sequence(this, exprs);
-                }
-                if (exp instanceof AST_Function) {
-                    if (exp.name) {
-                        var def = exp.name.definition();
-                        if (def.references.length > def.replaced) return this;
-                    }
-                    exp.process_expression(false, function(node) {
-                        var value = node.value && node.value.drop_side_effect_free(compressor, true);
-                        return value ? make_node(AST_SimpleStatement, node, {
-                            body: value
-                        }) : make_node(AST_EmptyStatement, node);
-                    });
-                    scan_local_returns(exp, function(node) {
-                        if (node.value) node.value = node.value.drop_side_effect_free(compressor);
-                    });
-                    // always shallow clone to ensure stripping of negated IIFEs
-                    return this.clone();
-                }
-                return this;
             }
-            if (this.pure) AST_Node.warn("Dropping __PURE__ call [{file}:{line},{col}]", this.start);
+            var exp = self.expression;
-            var args = trim(this.args, compressor, first_in_statement);
+            if (self.is_call_pure(compressor)) {
-            return args && make_sequence(this, args);
+                var exprs = self.args.slice();
+                exprs.unshift(exp.expression);
+                exprs = trim(exprs, compressor, first_in_statement);
+                return exprs && make_sequence(self, exprs);
+            }
+            var def;
+            if (exp instanceof AST_Function
+                && !(exp.name && (def = exp.name.definition()).references.length > def.replaced)) {
+                exp.process_expression(false, function(node) {
+                    var value = node.value && node.value.drop_side_effect_free(compressor, true);
+                    return value ? make_node(AST_SimpleStatement, node, {
+                        body: value
+                    }) : make_node(AST_EmptyStatement, node);
+                });
+                scan_local_returns(exp, function(node) {
+                    if (node.value) node.value = node.value.drop_side_effect_free(compressor);
+                });
+                // always shallow clone to ensure stripping of negated IIFEs
+                self = self.clone();
+            }
+            if (self instanceof AST_New) {
+                var fn = exp;
+                if (fn instanceof AST_SymbolRef) fn = fn.fixed_value();
+                if (fn instanceof AST_Lambda) {
+                    fn.new = true;
+                    var assign_this_only = all(fn.body, function(stat) {
+                        return !stat.has_side_effects(compressor);
+                    });
+                    delete fn.new;
+                    if (assign_this_only) {
+                        var exprs = self.args.slice();
+                        exprs.unshift(exp);
+                        exprs = trim(exprs, compressor, first_in_statement);
+                        return exprs && make_sequence(self, exprs);
+                    }
+                    if (!fn.contains_this()) return make_node(AST_Call, self, self);
+                }
+            }
+            return self;
         });
         def(AST_Conditional, function(compressor) {
             var consequent = this.consequent.drop_side_effect_free(compressor);
@@ -5766,11 +5829,12 @@ merge(Compressor.prototype, {
         return compressor.option("loops") ? make_node(AST_For, self, self).optimize(compressor) : self;
     });
 
-    function has_break_or_continue(loop, parent) {
+    function has_loop_control(loop, parent, type) {
+        if (!type) type = AST_LoopControl;
         var found = false;
         var tw = new TreeWalker(function(node) {
             if (found || node instanceof AST_Scope) return true;
-            if (node instanceof AST_LoopControl && tw.loopcontrol_target(node) === loop) {
+            if (node instanceof type && tw.loopcontrol_target(node) === loop) {
                 return found = true;
             }
         });
@@ -5794,7 +5858,7 @@ merge(Compressor.prototype, {
                     ]
                 })
             }).optimize(compressor);
-            if (!has_break_or_continue(self, compressor.parent())) {
+            if (!has_loop_control(self, compressor.parent())) {
                 return make_node(AST_BlockStatement, self.body, {
                     body: [
                         self.body,
@@ -5805,6 +5869,33 @@ merge(Compressor.prototype, {
                 }).optimize(compressor);
             }
         }
+        if (self.body instanceof AST_BlockStatement && !has_loop_control(self, compressor.parent(), AST_Continue)) {
+            var body = self.body.body;
+            for (var i = body.length; --i >= 0;) {
+                var stat = body[i];
+                if (stat instanceof AST_If
+                    && !stat.alternative
+                    && stat.body instanceof AST_Break
+                    && compressor.loopcontrol_target(stat.body) === self) {
+                    self.condition = make_node(AST_Binary, self, {
+                        operator: "&&",
+                        left: stat.condition.negate(compressor),
+                        right: self.condition,
+                    });
+                    body.splice(i, 1);
+                } else if (stat instanceof AST_SimpleStatement) {
+                    self.condition = make_sequence(self, [
+                        stat.body,
+                        self.condition,
+                    ]);
+                    body.splice(i, 1);
+                } else if (!is_declaration(stat)) {
+                    break;
+                }
+            }
+            self.body = trim_block(self.body);
+        }
+        if (self.body instanceof AST_EmptyStatement) return make_node(AST_For, self, self).optimize(compressor);
         if (self.body instanceof AST_SimpleStatement) return make_node(AST_For, self, {
             condition: make_sequence(self.condition, [
                 self.body.body,
@@ -6736,7 +6827,7 @@ merge(Compressor.prototype, {
             if (self.args.length == 0) return make_node(AST_Function, self, {
                 argnames: [],
                 body: []
-            }).init_scope_vars(exp.scope);
+            }).init_vars(exp.scope);
             if (all(self.args, function(x) {
                 return x instanceof AST_String;
             })) {
@@ -6804,7 +6895,7 @@ merge(Compressor.prototype, {
                 && !fn.pinned()
                 && !(fn.name && fn instanceof AST_Function)
                 && (exp === fn || !recursive_ref(compressor, def = exp.definition())
-                    && fn.is_constant_expression(compressor.find_parent(AST_Scope)))
+                    && fn.is_constant_expression(find_scope(compressor)))
                 && (value = can_flatten_body(stat))
                 && !fn.contains_this()) {
                 var replacing = exp === fn || compressor.option("unused") && def.references.length - def.replaced == 1;
@@ -6830,7 +6921,7 @@ merge(Compressor.prototype, {
                         return arg;
                     })).optimize(compressor);
                     node = maintain_this_binding(compressor, compressor.parent(), compressor.self(), node);
-                    if (replacing || best_of(compressor, self, node) === node) {
+                    if (replacing || best_of_expression(node, self) === node) {
                         refs.forEach(function(ref) {
                             var def = ref.definition();
                             def.references.push(ref);
@@ -6991,6 +7082,9 @@ merge(Compressor.prototype, {
                 var stat = fn.body[i];
                 if (stat instanceof AST_Defun) {
                     if (!safe_to_inject || var_exists(used, stat.name.name)) return false;
+                    if (!all(stat.enclosed, function(def) {
+                        return def.scope === stat || !catches[def.name];
+                    })) return false;
                     continue;
                 }
                 if (!(stat instanceof AST_Var)) continue;
@@ -7012,7 +7106,7 @@ merge(Compressor.prototype, {
                 child = scope;
                 scope = compressor.parent(++level);
                 if (scope instanceof AST_Catch) {
-                    catches[scope.argname.name] = true;
+                    if (scope.argname) catches[scope.argname.name] = true;
                 } else if (scope instanceof AST_DWLoop) {
                     in_loop = [];
                 } else if (scope instanceof AST_For) {
@@ -7027,7 +7121,7 @@ merge(Compressor.prototype, {
                 }
             } while (!(scope instanceof AST_Scope));
             var safe_to_inject = (!(scope instanceof AST_Toplevel) || compressor.toplevel.vars)
-                && (exp !== fn || fn.parent_scope === compressor.find_parent(AST_Scope));
+                && (exp !== fn || fn.parent_scope.resolve() === compressor.find_parent(AST_Scope));
             var inline = compressor.option("inline");
             var used = Object.create(catches);
             if (!can_inject_args(catches, used, inline >= 2 && safe_to_inject)) return false;
@@ -7046,9 +7140,10 @@ merge(Compressor.prototype, {
                     value: null
                 }));
             }
+            if (!value) return;
             var sym = make_node(AST_SymbolRef, name, name);
             def.references.push(sym);
-            if (value) expressions.push(make_node(AST_Assign, self, {
+            expressions.push(make_node(AST_Assign, self, {
                 operator: "=",
                 left: sym,
                 right: value
@@ -7069,7 +7164,12 @@ merge(Compressor.prototype, {
                     var symbol = make_node(AST_SymbolVar, name, name);
                     name.definition().orig.push(symbol);
                     if (!value && in_loop) value = make_node(AST_Undefined, self);
-                    append_var(decls, expressions, symbol, value);
+                    if ("__unused" in name) {
+                        append_var(decls, expressions, symbol);
+                        if (value) expressions.push(value);
+                    } else {
+                        append_var(decls, expressions, symbol, value);
+                    }
                 }
             }
             decls.reverse();
@@ -7381,6 +7481,15 @@ merge(Compressor.prototype, {
             || node instanceof AST_Object;
     }
 
+    function repeatable(compressor, node) {
+        if (node instanceof AST_Dot) return repeatable(compressor, node.expression);
+        if (node instanceof AST_Sub) {
+            return repeatable(compressor, node.expression) && repeatable(compressor, node.property);
+        }
+        if (node instanceof AST_Symbol) return true;
+        return !node.has_side_effects(compressor);
+    }
+
     OPT(AST_Binary, function(self, compressor) {
         function reversible() {
             return self.left.is_constant()
@@ -7449,7 +7558,7 @@ merge(Compressor.prototype, {
             if ((self.left.is_string(compressor) && self.right.is_string(compressor)) ||
                 (self.left.is_number(compressor) && self.right.is_number(compressor)) ||
                 (self.left.is_boolean(compressor) && self.right.is_boolean(compressor)) ||
-                can_self_compare(self.left) && self.left.equivalent_to(self.right)) {
+                repeatable(compressor, self.left) && self.left.equivalent_to(self.right)) {
                 self.operator = self.operator.slice(0, 2);
             }
             // XXX: intentionally falling down to the next case
@@ -7954,13 +8063,6 @@ merge(Compressor.prototype, {
         }
         return try_evaluate(compressor, self);
 
-        function can_self_compare(node) {
-            if (node instanceof AST_Dot) return can_self_compare(node.expression);
-            if (node instanceof AST_Sub) return can_self_compare(node.expression) && can_self_compare(node.property);
-            if (node instanceof AST_Symbol) return true;
-            return !node.has_side_effects(compressor);
-        }
-
         function align(ref, op) {
             switch (ref) {
               case "-":
@@ -8041,7 +8143,7 @@ merge(Compressor.prototype, {
         if (!compressor.option("ie8")
             && is_undeclared_ref(self)
             // testing against `self.scope.uses_with` is an optimization
-            && !(self.scope.uses_with && compressor.find_parent(AST_With))) {
+            && !(self.scope.resolve().uses_with && compressor.find_parent(AST_With))) {
             switch (self.name) {
               case "undefined":
                 return make_node(AST_Undefined, self).optimize(compressor);
@@ -8058,14 +8160,14 @@ merge(Compressor.prototype, {
             var single_use = def.single_use && !(parent instanceof AST_Call && parent.is_expr_pure(compressor));
             if (single_use) {
                 if (fixed instanceof AST_Lambda) {
-                    if ((def.scope !== self.scope || def.in_loop)
+                    if ((def.scope !== self.scope.resolve() || def.in_loop)
                         && (!compressor.option("reduce_funcs") || def.escaped.depth == 1 || fixed.inlined)) {
                         single_use = false;
                     } else if (recursive_ref(compressor, def)) {
                         single_use = false;
                     } else if (fixed.name && fixed.name.definition() !== def) {
                         single_use = false;
-                    } else if (def.scope !== self.scope || def.orig[0] instanceof AST_SymbolFunarg) {
+                    } else if (fixed.parent_scope !== self.scope.resolve() || def.orig[0] instanceof AST_SymbolFunarg) {
                         single_use = fixed.is_constant_expression(self.scope);
                         if (single_use == "f") {
                             var scope = self.scope;
@@ -8213,7 +8315,7 @@ merge(Compressor.prototype, {
 
     OPT(AST_Undefined, function(self, compressor) {
         if (compressor.option("unsafe_undefined")) {
-            var undef = find_variable(compressor, "undefined");
+            var undef = find_scope(compressor).find_variable("undefined");
             if (undef) {
                 var ref = make_node(AST_SymbolRef, self, {
                     name   : "undefined",
@@ -8239,7 +8341,7 @@ merge(Compressor.prototype, {
         if (lhs && is_atomic(lhs, self)) return self;
         if (compressor.option("keep_infinity")
             && !(lhs && !is_atomic(lhs, self))
-            && !find_variable(compressor, "Infinity"))
+            && !find_scope(compressor).find_variable("Infinity"))
             return self;
         return make_node(AST_Binary, self, {
             operator: "/",
@@ -8254,8 +8356,7 @@ merge(Compressor.prototype, {
 
     OPT(AST_NaN, function(self, compressor) {
         var lhs = is_lhs(compressor.self(), compressor.parent());
-        if (lhs && !is_atomic(lhs, self)
+        if (lhs && !is_atomic(lhs, self) || find_scope(compressor).find_variable("NaN")) {
-            || find_variable(compressor, "NaN")) {
             return make_node(AST_Binary, self, {
                 operator: "/",
                 left: make_node(AST_Number, self, {
@@ -8422,14 +8523,13 @@ merge(Compressor.prototype, {
     });
 
     OPT(AST_Conditional, function(self, compressor) {
-        if (!compressor.option("conditionals")) return self;
+        if (compressor.option("sequences") && self.condition instanceof AST_Sequence) {
-        // This looks like lift_sequences(), should probably be under "sequences"
-        if (self.condition instanceof AST_Sequence) {
             var expressions = self.condition.expressions.slice();
             self.condition = expressions.pop();
             expressions.push(self);
             return make_sequence(self, expressions);
         }
+        if (!compressor.option("conditionals")) return self;
         var condition = self.condition.is_truthy() || self.condition.evaluate(compressor, true);
         if (!condition) {
             AST_Node.warn("Condition always false [{file}:{line},{col}]", self.start);
@@ -8450,15 +8550,19 @@ merge(Compressor.prototype, {
         }
         var consequent = self.consequent;
         var alternative = self.alternative;
-        // x ? x : y => x || y
+        if (repeatable(compressor, condition)) {
-        if (condition instanceof AST_SymbolRef
+            // x ? x : y => x || y
-            && consequent instanceof AST_SymbolRef
+            if (condition.equivalent_to(consequent)) return make_node(AST_Binary, self, {
-            && condition.definition() === consequent.definition()) {
-            return make_node(AST_Binary, self, {
                 operator: "||",
                 left: condition,
-                right: alternative
+                right: alternative,
-            });
+            }).optimize(compressor);
+            // x ? y : x => x && y
+            if (condition.equivalent_to(alternative)) return make_node(AST_Binary, self, {
+                operator: "&&",
+                left: condition,
+                right: consequent,
+            }).optimize(compressor);
         }
         // if (foo) exp = something; else exp = something_else;
         //                   |
@@ -8846,7 +8950,7 @@ merge(Compressor.prototype, {
             && expr instanceof AST_SymbolRef
             && is_arguments(def = expr.definition())
             && prop instanceof AST_Number
-            && (fn = expr.scope) === find_lambda()) {
+            && (fn = expr.scope.resolve()) === find_lambda()) {
             var index = prop.value;
             if (parent instanceof AST_UnaryPrefix && parent.operator == "delete") {
                 if (!def.deleted) def.deleted = [];
@@ -9020,7 +9124,7 @@ merge(Compressor.prototype, {
                 self.expression = make_node(AST_Function, self.expression, {
                     argnames: [],
                     body: []
-                }).init_scope_vars(exp.scope);
+                }).init_vars(exp.scope);
                 break;
               case "Number":
                 self.expression = make_node(AST_Number, self.expression, {

lib/output.js

@@ -1099,10 +1099,12 @@ function OutputStream(options) {
     DEFPRINT(AST_Catch, function(output) {
         var self = this;
         output.print("catch");
-        output.space();
+        if (self.argname) {
-        output.with_parens(function() {
+            output.space();
-            self.argname.print(output);
+            output.with_parens(function() {
-        });
+                self.argname.print(output);
+            });
+        }
         output.space();
         print_braced(self, output);
     });

lib/parse.js

@@ -60,8 +60,9 @@ KEYWORDS_ATOM = makePredicate(KEYWORDS_ATOM);
 
 var OPERATOR_CHARS = makePredicate(characters("+-*&%=<>!?|~^"));
 
-var RE_HEX_NUMBER = /^0x[0-9a-f]+$/i;
+var RE_BIN_NUMBER = /^0b([01]+)$/i;
-var RE_OCT_NUMBER = /^0[0-7]+$/;
+var RE_HEX_NUMBER = /^0x([0-9a-f]+)$/i;
+var RE_OCT_NUMBER = /^0o?([0-7]+)$/i;
 
 var OPERATORS = makePredicate([
     "in",
@@ -147,10 +148,6 @@ function is_digit(code) {
     return code >= 48 && code <= 57;
 }
 
-function is_alphanumeric_char(code) {
-    return is_digit(code) || is_letter(code);
-}
-
 function is_unicode_digit(code) {
     return UNICODE.digit.test(String.fromCharCode(code));
 }
@@ -184,14 +181,12 @@ function is_identifier_string(str) {
 }
 
 function parse_js_number(num) {
-    if (RE_HEX_NUMBER.test(num)) {
+    var match;
-        return parseInt(num.substr(2), 16);
+    if (match = RE_BIN_NUMBER.exec(num)) return parseInt(match[1], 2);
-    } else if (RE_OCT_NUMBER.test(num)) {
+    if (match = RE_HEX_NUMBER.exec(num)) return parseInt(match[1], 16);
-        return parseInt(num.substr(1), 8);
+    if (match = RE_OCT_NUMBER.exec(num)) return parseInt(match[1], 8);
-    } else {
+    var val = parseFloat(num);
-        var val = parseFloat(num);
+    if (val == num) return val;
-        if (val == num) return val;
-    }
 }
 
 function JS_Parse_Error(message, filename, line, col, pos) {
@@ -347,11 +342,13 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
               case (after_e = false, 46): // .
                 return (!has_dot && !has_x && !has_e) ? (has_dot = true) : false;
             }
-            return is_alphanumeric_char(code);
+            return is_digit(code) || is_letter(code) || ch == "_";
         });
         if (prefix) num = prefix + num;
-        if (RE_OCT_NUMBER.test(num) && next_token.has_directive("use strict")) {
+        if (/^0[0-7_]+$/.test(num)) {
-            parse_error("Legacy octal literals are not allowed in strict mode");
+            if (next_token.has_directive("use strict")) parse_error("Legacy octal literals are not allowed in strict mode");
+        } else {
+            num = num.replace(has_x ? /([1-9a-f]|.0)_(?=[0-9a-f])/gi : /([1-9]|.0)_(?=[0-9])/gi, "$1");
         }
         var valid = parse_js_number(num);
         if (!isNaN(valid)) return token("num", valid);
@@ -1133,9 +1130,12 @@ function parse($TEXT, options) {
         if (is("keyword", "catch")) {
             var start = S.token;
             next();
-            expect("(");
+            var name = null;
-            var name = as_symbol(AST_SymbolCatch);
+            if (is("punc", "(")) {
-            expect(")");
+                next();
+                name = as_symbol(AST_SymbolCatch);
+                expect(")");
+            }
             bcatch = new AST_Catch({
                 start   : start,
                 argname : name,

lib/scope.js

@@ -59,13 +59,9 @@ function SymbolDef(id, scope, orig, init) {
 }
 
 SymbolDef.prototype = {
-    unmangleable: function(options) {
+    forEach: function(fn) {
-        return this.global && !options.toplevel
+        this.orig.forEach(fn);
-            || this.undeclared
+        this.references.forEach(fn);
-            || !options.eval && this.scope.pinned()
-            || options.keep_fnames
-                && (this.orig[0] instanceof AST_SymbolLambda
-                    || this.orig[0] instanceof AST_SymbolDefun);
     },
     mangle: function(options) {
         var cache = options.cache && options.cache.props;
@@ -85,7 +81,15 @@ SymbolDef.prototype = {
     },
     redefined: function() {
         return this.defun && this.defun.variables.get(this.name);
-    }
+    },
+    unmangleable: function(options) {
+        return this.global && !options.toplevel
+            || this.undeclared
+            || !options.eval && this.scope.pinned()
+            || options.keep_fnames
+                && (this.orig[0] instanceof AST_SymbolLambda
+                    || this.orig[0] instanceof AST_SymbolDefun);
+    },
 };
 
 AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
@@ -100,26 +104,35 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
     var next_def_id = 0;
     var scope = self.parent_scope = null;
     var tw = new TreeWalker(function(node, descend) {
-        if (node instanceof AST_Catch) {
+        if (node instanceof AST_Defun) {
-            var save_scope = scope;
+            node.name.walk(tw);
-            scope = new AST_Scope(node);
+            walk_scope(function() {
-            scope.init_scope_vars(save_scope);
+                node.argnames.forEach(function(argname) {
-            descend();
+                    argname.walk(tw);
-            scope = save_scope;
+                });
+                walk_body(node, tw);
+            });
             return true;
         }
-        if (node instanceof AST_Scope) {
+        if (node instanceof AST_Try) {
-            node.init_scope_vars(scope);
+            walk_scope(function() {
-            var save_scope = scope;
+                walk_body(node, tw);
-            var save_defun = defun;
+            });
-            defun = scope = node;
+            if (node.bcatch) node.bcatch.walk(tw);
-            descend();
+            if (node.bfinally) node.bfinally.walk(tw);
-            scope = save_scope;
+            return true;
-            defun = save_defun;
+        }
+        if (node instanceof AST_BlockScope) {
+            walk_scope(descend);
             return true;
         }
         if (node instanceof AST_With) {
-            for (var s = scope; s; s = s.parent_scope) s.uses_with = true;
+            var s = scope;
+            do {
+                s = s.resolve();
+                if (s.uses_with) break;
+                s.uses_with = true;
+            } while (s = s.parent_scope);
             return;
         }
         if (node instanceof AST_Symbol) {
@@ -129,25 +142,41 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             node.thedef = node;
             node.references = [];
         }
-        if (node instanceof AST_SymbolDefun) {
+        if (node instanceof AST_SymbolCatch) {
-            // This should be defined in the parent scope, as we encounter the
+            scope.def_variable(node).defun = defun;
-            // AST_Defun node before getting to its AST_Symbol.
+        } else if (node instanceof AST_SymbolDefun) {
-            (node.scope = defun.parent_scope.resolve()).def_function(node, defun);
+            defun.def_function(node, tw.parent());
+            entangle(defun, scope);
+        } else if (node instanceof AST_SymbolFunarg) {
+            defun.def_variable(node);
+            entangle(defun, scope);
         } else if (node instanceof AST_SymbolLambda) {
             var def = defun.def_function(node, node.name == "arguments" ? undefined : defun);
             if (options.ie8) def.defun = defun.parent_scope.resolve();
         } else if (node instanceof AST_SymbolVar) {
-            defun.def_variable(node, node.TYPE == "SymbolVar" ? null : undefined);
+            defun.def_variable(node, null);
-            if (defun !== scope) {
+            entangle(defun, scope);
-                node.mark_enclosed(options);
+        }
-                var def = scope.find_variable(node);
+
-                if (node.thedef !== def) {
+        function walk_scope(descend) {
-                    node.thedef = def;
+            node.init_vars(scope);
-                }
+            var save_defun = defun;
-                node.reference(options);
+            var save_scope = scope;
-            }
+            if (node instanceof AST_Scope) defun = node;
-        } else if (node instanceof AST_SymbolCatch) {
+            scope = node;
-            scope.def_variable(node).defun = defun;
+            descend();
+            scope = save_scope;
+            defun = save_defun;
+        }
+
+        function entangle(defun, scope) {
+            if (defun === scope) return;
+            node.mark_enclosed(options);
+            var def = scope.find_variable(node);
+            if (node.thedef === def) return;
+            node.thedef = def;
+            def.orig.push(node);
+            node.mark_enclosed(options);
         }
     });
     self.make_def = function(orig, init) {
@@ -167,15 +196,18 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             var sym = node.scope.find_variable(name);
             if (!sym) {
                 sym = self.def_global(node);
-            } else if (sym.scope instanceof AST_Lambda && name == "arguments") {
+            } else if (name == "arguments" && sym.scope instanceof AST_Lambda) {
                 sym.scope.uses_arguments = true;
             }
             if (name == "eval") {
                 var parent = tw.parent();
                 if (parent.TYPE == "Call" && parent.expression === node) {
-                    for (var s = node.scope; s && !s.uses_eval; s = s.parent_scope) {
+                    var s = node.scope;
+                    do {
+                        s = s.resolve();
+                        if (s.uses_eval) break;
                         s.uses_eval = true;
-                    }
+                    } while (s = s.parent_scope);
                 } else if (sym.undeclared) {
                     self.uses_eval = true;
                 }
@@ -234,7 +266,8 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             new_def = scope.def_variable(node);
         }
         old_def.defun = new_def.scope;
-        old_def.orig.concat(old_def.references).forEach(function(node) {
+        old_def.forEach(function(node) {
+            node.redef = true;
             node.thedef = new_def;
             node.reference(options);
         });
@@ -256,22 +289,28 @@ AST_Toplevel.DEFMETHOD("def_global", function(node) {
     }
 });
 
-function init_scope_vars(scope, parent) {
+function init_block_vars(scope, parent) {
     scope.cname = -1;                               // the current index for mangling functions/variables
     scope.enclosed = [];                            // variables from this or outer scope(s) that are referenced from this or inner scopes
-    scope.uses_eval = false;                        // will be set to true if this or nested scope uses the global `eval`
-    scope.uses_with = false;                        // will be set to true if this or some nested scope uses the `with` statement
     scope.parent_scope = parent;                    // the parent scope (null if this is the top level)
     scope.functions = new Dictionary();             // map name to AST_SymbolDefun (functions defined in this scope)
     scope.variables = new Dictionary();             // map name to AST_SymbolVar (variables defined in this scope; includes functions)
     if (parent) scope.make_def = parent.make_def;   // top-level tracking of SymbolDef instances
 }
 
-AST_Scope.DEFMETHOD("init_scope_vars", function(parent_scope) {
+function init_scope_vars(scope, parent) {
+    init_block_vars(scope, parent);
+    scope.uses_eval = false;                        // will be set to true if this or nested scope uses the global `eval`
+    scope.uses_with = false;                        // will be set to true if this or some nested scope uses the `with` statement
+}
+
+AST_BlockScope.DEFMETHOD("init_vars", function(parent_scope) {
+    init_block_vars(this, parent_scope);
+});
+AST_Scope.DEFMETHOD("init_vars", function(parent_scope) {
     init_scope_vars(this, parent_scope);
 });
-
+AST_Lambda.DEFMETHOD("init_vars", function(parent_scope) {
-AST_Lambda.DEFMETHOD("init_scope_vars", function(parent_scope) {
     init_scope_vars(this, parent_scope);
     this.uses_arguments = false;
     this.def_variable(new AST_SymbolFunarg({
@@ -300,20 +339,20 @@ AST_Symbol.DEFMETHOD("reference", function(options) {
     this.mark_enclosed(options);
 });
 
-AST_Scope.DEFMETHOD("find_variable", function(name) {
+AST_BlockScope.DEFMETHOD("find_variable", function(name) {
     if (name instanceof AST_Symbol) name = name.name;
     return this.variables.get(name)
         || (this.parent_scope && this.parent_scope.find_variable(name));
 });
 
-AST_Scope.DEFMETHOD("def_function", function(symbol, init) {
+AST_BlockScope.DEFMETHOD("def_function", function(symbol, init) {
     var def = this.def_variable(symbol, init);
     if (!def.init || def.init instanceof AST_Defun) def.init = init;
     this.functions.set(symbol.name, def);
     return def;
 });
 
-AST_Scope.DEFMETHOD("def_variable", function(symbol, init) {
+AST_BlockScope.DEFMETHOD("def_variable", function(symbol, init) {
     var def = this.variables.get(symbol.name);
     if (def) {
         def.orig.push(symbol);
@@ -326,12 +365,6 @@ AST_Scope.DEFMETHOD("def_variable", function(symbol, init) {
     return symbol.thedef = def;
 });
 
-AST_Lambda.DEFMETHOD("resolve", return_this);
-AST_Scope.DEFMETHOD("resolve", function() {
-    return this.parent_scope.resolve();
-});
-AST_Toplevel.DEFMETHOD("resolve", return_this);
-
 function names_in_use(scope, options) {
     var names = scope.names_in_use;
     if (!names) {
@@ -353,7 +386,7 @@ function next_mangled_name(scope, options, def) {
     var holes = scope.cname_holes;
     var names = Object.create(null);
     var scopes = [ scope ];
-    def.references.forEach(function(sym) {
+    def.forEach(function(sym) {
         var scope = sym.scope;
         do {
             if (scopes.indexOf(scope) < 0) {
@@ -457,7 +490,7 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options) {
             node.mangled_name = name;
             return true;
         }
-        if (!options.ie8 && node instanceof AST_Catch) {
+        if (!options.ie8 && node instanceof AST_Catch && node.argname) {
             var def = node.argname.definition();
             var redef = defer_redef(def, node.argname);
             descend();
@@ -495,8 +528,7 @@ AST_Toplevel.DEFMETHOD("find_colliding_names", function(options) {
     options.reserved.forEach(to_avoid);
     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_BlockScope) node.variables.each(add_def);
-        if (node instanceof AST_SymbolCatch) add_def(node.definition());
     }));
     return avoid;
 
@@ -520,8 +552,7 @@ AST_Toplevel.DEFMETHOD("expand_names", function(options) {
     var cname = 0;
     this.globals.each(rename);
     this.walk(new TreeWalker(function(node) {
-        if (node instanceof AST_Scope) node.variables.each(rename);
+        if (node instanceof AST_BlockScope) node.variables.each(rename);
-        if (node instanceof AST_SymbolCatch) rename(node.definition());
     }));
 
     function next_name() {
@@ -539,7 +570,7 @@ AST_Toplevel.DEFMETHOD("expand_names", function(options) {
         var redef = def.redefined();
         var name = redef ? redef.rename || redef.name : next_name();
         def.rename = name;
-        def.orig.concat(def.references).forEach(function(sym) {
+        def.forEach(function(sym) {
             if (sym.definition() === def) sym.name = name;
         });
     }

lib/transform.js

@@ -116,7 +116,7 @@ TreeTransformer.prototype = new TreeWalker;
         if (self.bfinally) self.bfinally = self.bfinally.transform(tw);
     });
     DEF(AST_Catch, function(self, tw) {
-        self.argname = self.argname.transform(tw);
+        if (self.argname) self.argname = self.argname.transform(tw);
         self.body = do_list(self.body, tw);
     });
     DEF(AST_Definitions, function(self, tw) {

package.json

@@ -3,7 +3,7 @@
   "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.11.0",
+  "version": "3.11.2",
   "engines": {
     "node": ">=0.8.0"
   },

test/compress/conditionals.js

@@ -1159,7 +1159,7 @@ issue_1645_2: {
     expect_stdout: true
 }
 
-condition_symbol_matches_consequent: {
+condition_matches_consequent: {
     options = {
         conditionals: true,
     }
@@ -1188,6 +1188,35 @@ condition_symbol_matches_consequent: {
     expect_stdout: "3 7 true 4"
 }
 
+condition_matches_alternative: {
+    options = {
+        conditionals: true,
+    }
+    input: {
+        function foo(x, y) {
+            return x.p ? y[0] : x.p;
+        }
+        function bar() {
+            return g ? h : g;
+        }
+        var g = 4;
+        var h = 5;
+        console.log(foo({ p: 3 }, [ null ]), foo({ p: 0 }, [ 7 ]), foo({ p: true } , [ false ]), bar());
+    }
+    expect: {
+        function foo(x, y) {
+            return x.p && y[0];
+        }
+        function bar() {
+            return g && h;
+        }
+        var g = 4;
+        var h = 5;
+        console.log(foo({ p: 3 }, [ null ]), foo({ p: 0 }, [ 7 ]), foo({ p: true } , [ false ]), bar());
+    }
+    expect_stdout: "null 0 false 5"
+}
+
 delete_conditional_1: {
     options = {
         booleans: true,

test/compress/drop-unused.js

@@ -2992,3 +2992,96 @@ issue_4146: {
     }
     expect_stdout: "function"
 }
+
+var_catch_redefined: {
+    options = {
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            throw "PASS";
+        } catch (a) {
+            function f() {
+                return a;
+            }
+            console.log(a);
+        }
+        f();
+    }
+    expect: {
+        var a = "FAIL";
+        try {
+            throw "PASS";
+        } catch (a) {
+            function f() {
+                return a;
+            }
+            console.log(a);
+        }
+        f();
+    }
+    expect_stdout: "PASS"
+}
+
+single_use_catch_redefined: {
+    options = {
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect_stdout: true
+}
+
+issue_4184: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            var a = function() {}, b = [ a, 1 && b, a = {} ];
+            try {
+                throw 42;
+            } catch (a) {
+                {
+                    console.log(a);
+                }
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            var b = [ function() {}, 1 && b, {} ];
+            try {
+                throw 42;
+            } catch (a) {
+                console.log(a);
+            }
+        })();
+    }
+    expect_stdout: "42"
+}

test/compress/functions.js

@@ -4808,3 +4808,271 @@ issue_4155: {
         "function",
     ]
 }
+
+issue_4159: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 42, c = function(b) {
+            (b = a) && console.log(a++, b);
+        }(c = a);
+    }
+    expect: {
+        var a = 42;
+        (b = a) && console.log(a++, b);
+        var b;
+    }
+    expect_stdout: "42 42"
+}
+
+direct_inline: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f(a, b) {
+            function g(c) {
+                return c >> 1;
+            }
+            return g(a) + g(b);
+        }
+        console.log(f(13, 31));
+    }
+    expect: {
+        function f(a, b) {
+            return (a >> 1) + (b >> 1);
+        }
+        console.log(f(13, 31));
+    }
+    expect_stdout: "21"
+}
+
+direct_inline_catch_redefined: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 1;
+        function f() {
+            return a;
+        }
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+            console.log(a, f(), g());
+        }
+        console.log(a, f(), g());
+    }
+    expect: {
+        var a = 1;
+        function f() {
+            return a;
+        }
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+            console.log(a, f(), g());
+        }
+        console.log(a, a, g());
+    }
+    expect_stdout: true
+}
+
+issue_4171_1: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            try {
+                while (a)
+                    var e = function() {};
+            } catch (e) {
+                return function() {
+                    return e;
+                };
+            }
+        }(!console));
+    }
+    expect: {
+        console.log(function(a) {
+            try {
+                while (a)
+                    var e = function() {};
+            } catch (e) {
+                return function() {
+                    return e;
+                };
+            }
+        }(!console));
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4171_2: {
+    options = {
+        functions: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            try {
+                while (a);
+            } catch (e) {
+                return function() {
+                    return e;
+                };
+            } finally {
+                var e = function() {};
+            }
+        }(!console));
+    }
+    expect: {
+        console.log(function(a) {
+            try {
+                while (a);
+            } catch (e) {
+                return function() {
+                    return e;
+                };
+            } finally {
+                function e() {}
+            }
+        }(!console));
+    }
+    expect_stdout: "undefined"
+}
+
+catch_defun: {
+    mangle = {
+        toplevel: true,
+    }
+    input: {
+        try {
+            throw 42;
+        } catch (a) {
+            function f() {
+                return typeof a;
+            }
+        }
+        console.log(f());
+    }
+    expect: {
+        try {
+            throw 42;
+        } catch (o) {
+            function t() {
+                return typeof o;
+            }
+        }
+        console.log(t());
+    }
+    expect_stdout: true
+}
+
+catch_no_argname: {
+    options = {
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = "PASS";
+        function f() {
+            return a;
+        }
+        try {
+            throw a;
+        } catch {
+            function g() {
+                return a;
+            }
+            console.log(a, f(), g());
+        }
+        console.log(a, f(), g());
+    }
+    expect: {
+        var a = "PASS";
+        try {
+            throw a;
+        } catch {
+            console.log(a, a, a);
+        }
+        console.log(a, a, a);
+    }
+    expect_stdout: [
+        "PASS PASS PASS",
+        "PASS PASS PASS",
+    ]
+    node_version: ">=10"
+}
+
+issue_4186: {
+    options = {
+        conditionals: true,
+        inline: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        sequences: true,
+        unused: true,
+    }
+    input: {
+        console.log(typeof function() {
+            return function() {
+                function f() {
+                    if (1)
+                        g();
+                    else
+                        (function() {
+                            return f;
+                        });
+                }
+                return f;
+                function g() {
+                    if (1) {
+                        if (0)
+                            h;
+                        else
+                            h();
+                        var key = 0;
+                    }
+                }
+                function h() {
+                    return factory;
+                }
+            };
+        }()());
+    }
+    expect: {
+        console.log(typeof function() {
+            return function f() {
+                1 ? void (1 && (0 ? h : h(), 0)) : function() {
+                    return f;
+                };
+            };
+            function h() {
+                return factory;
+            }
+        }());
+    }
+    expect_stdout: "function"
+}

test/compress/ie8.js

@@ -2714,3 +2714,148 @@ issue_2737: {
     }
     expect_stdout: "function"
 }
+
+single_use_catch_redefined: {
+    options = {
+        ie8: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect_stdout: true
+}
+
+single_use_inline_catch_redefined: {
+    options = {
+        ie8: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect: {
+        var a = 1;
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+        }
+        console.log(g());
+    }
+    expect_stdout: true
+}
+
+direct_inline_catch_redefined: {
+    options = {
+        ie8: true,
+        inline: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 1;
+        function f() {
+            return a;
+        }
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+            console.log(a, f(), g());
+        }
+        console.log(a, f(), g());
+    }
+    expect: {
+        var a = 1;
+        function f() {
+            return a;
+        }
+        try {
+            throw 2;
+        } catch (a) {
+            function g() {
+                return a;
+            }
+            console.log(a, f(), g());
+        }
+        console.log(a, a, g());
+    }
+    expect_stdout: true
+}
+
+issue_4186: {
+    options = {
+        dead_code: true,
+        evaluate: true,
+        ie8: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    mangle = {
+        ie8: true,
+        toplevel: true,
+    }
+    input: {
+        function f() {
+            (function NaN() {
+                var a = 1;
+                while (a--)
+                    try {} finally {
+                        console.log(0/0);
+                        var b;
+                    }
+            })(f);
+        }
+        f();
+        NaN;
+    }
+    expect: {
+        (function() {
+            (function NaN() {
+                var n = 1;
+                while (n--)
+                    console.log(0/0);
+            })();
+        })();
+        NaN;
+    }
+    expect_stdout: "NaN"
+}

test/compress/if_return.js

@@ -663,3 +663,88 @@ nested_if_continue: {
         "even 21",
     ]
 }
+
+nested_if_return: {
+    options = {
+        conditionals: true,
+        if_return: true,
+    }
+    input: {
+        function f() {
+            if (A) {
+                if (B)
+                    return B;
+                if (C)
+                    return D;
+                if (E)
+                    return F;
+                if (G)
+                    return H;
+                if (I) {
+                    if (J)
+                        return K;
+                    return;
+                }
+                if (L) {
+                    if (M)
+                        return;
+                    return N;
+                }
+            }
+        }
+    }
+    expect: {
+        function f() {
+            if (A)
+                return B || (C ? D : E ? F : G ? H : I ? J ? K : void 0 : L && !M ? N : void 0);
+        }
+    }
+}
+
+issue_866_1: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: false,
+    };
+    input: {
+        function f(a) {
+            if (a)
+                return "";
+            console.log(a);
+        }
+    }
+    expect: {
+        function f(a) {
+            if (a)
+                return "";
+            console.log(a);
+        }
+    }
+}
+
+issue_866_2: {
+    options = {
+        conditionals: true,
+        if_return: true,
+        sequences: true,
+    }
+    input: {
+        (function() {
+            if (a)
+                if (b)
+                    c;
+                else
+                    return d;
+        })();
+    }
+    expect: {
+        (function() {
+            if (a) {
+                if (!b)
+                    return d;
+                c;
+            }
+        })();
+    }
+}

test/compress/issue-1052.js

@@ -16,7 +16,7 @@ multiple_functions: {
         ( function() {
             // NOTE: other compression steps will reduce this
             // down to just `window`.
-            if ( window );
+            if ( !window );
             function f() {}
             function g() {}
         } )();
@@ -38,7 +38,7 @@ single_function: {
     }
     expect: {
         ( function() {
-            if ( window );
+            if ( !window );
             function f() {}
         } )();
     }
@@ -67,7 +67,7 @@ deeply_nested: {
             // NOTE: other compression steps will reduce this
             // down to just `window`.
             if ( window )
-                if (document);
+                if ( !document );
             function f() {}
             function g() {}
             function h() {}

test/compress/issue-1105.js

@@ -151,15 +151,18 @@ Infinity_not_in_with_scope: {
         unused: true,
     }
     input: {
-        var o = { Infinity: 'oInfinity' };
+        var o = { Infinity: "FAIL" };
         var vInfinity = "Infinity";
         vInfinity = Infinity;
+        console.log(vInfinity);
     }
     expect: {
-        var o = { Infinity: 'oInfinity' }
+        var o = { Infinity: "FAIL" };
-        var vInfinity = "Infinity"
+        var vInfinity = "Infinity";
-        vInfinity = 1/0
+        vInfinity = 1/0;
+        console.log(vInfinity);
     }
+    expect_stdout: "Infinity"
 }
 
 Infinity_in_with_scope: {
@@ -167,15 +170,18 @@ Infinity_in_with_scope: {
         unused: true,
     }
     input: {
-        var o = { Infinity: 'oInfinity' };
+        var o = { Infinity: "PASS" };
         var vInfinity = "Infinity";
         with (o) { vInfinity = Infinity; }
+        console.log(vInfinity);
     }
     expect: {
-        var o = { Infinity: 'oInfinity' }
+        var o = { Infinity: "PASS" };
-        var vInfinity = "Infinity"
+        var vInfinity = "Infinity";
-        with (o) vInfinity = Infinity
+        with (o) vInfinity = Infinity;
+        console.log(vInfinity);
     }
+    expect_stdout: "PASS"
 }
 
 assorted_Infinity_NaN_undefined_in_with_scope: {

test/compress/loops.js

@@ -201,7 +201,7 @@ evaluate: {
     }
 }
 
-issue_1532: {
+issue_1532_1: {
     options = {
         evaluate: true,
         loops: true,
@@ -210,18 +210,56 @@ issue_1532: {
         function f(x, y) {
             do {
                 if (x) break;
-                foo();
+                console.log(y);
             } while (false);
         }
+        f(null, "PASS");
+        f(42, "FAIL");
+    }
+    expect: {
+        function f(x, y) {
+            for (; !x && (console.log(y), false););
+        }
+        f(null, "PASS");
+        f(42, "FAIL");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_1532_2: {
+    options = {
+        evaluate: true,
+        loops: true,
+    }
+    input: {
+        function f(x, y) {
+            do {
+                if (x) {
+                    console.log(x);
+                    break;
+                }
+                console.log(y);
+            } while (false);
+        }
+        f(null, "PASS");
+        f(42, "FAIL");
     }
     expect: {
         function f(x, y) {
             do {
-                if (x) break;
+                if (x) {
-                foo();
+                    console.log(x);
-            } while (false);
+                    break;
+                }
+            } while (console.log(y), false);
         }
+        f(null, "PASS");
+        f(42, "FAIL");
     }
+    expect_stdout: [
+        "PASS",
+        "42",
+    ]
 }
 
 issue_186: {
@@ -1088,3 +1126,74 @@ issue_4091_2: {
     }
     expect_stdout: "undefined"
 }
+
+issue_4182_1: {
+    options = {
+        loops: true,
+    }
+    input: {
+        (function() {
+            do {
+                try {
+                    return;
+                } finally {
+                    continue;
+                }
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect: {
+        (function() {
+            do {
+                try {
+                    return;
+                } finally {
+                    continue;
+                }
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+issue_4182_2: {
+    options = {
+        loops: true,
+    }
+    input: {
+        (function() {
+            L: do {
+                do {
+                    try {
+                        return;
+                    } finally {
+                        continue L;
+                    }
+                    console.log("FAIL");
+                } while (0);
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect: {
+        (function() {
+            L: do {
+                do {
+                    try {
+                        return;
+                    } finally {
+                        continue L;
+                    }
+                } while (console.log("FAIL"), 0);
+                console.log("FAIL");
+            } while (0);
+            console.log("PASS");
+        })();
+    }
+    expect_stdout: "PASS"
+}

test/compress/merge_vars.js

@@ -466,7 +466,7 @@ issue_4112: {
                 var o = e;
                 for (e in o);
                 var a = function() {};
-                console.log;
+                console.log(typeof a);
                 return a;
             }
         }());
@@ -479,12 +479,15 @@ issue_4112: {
                 var a = e;
                 for (e in a);
                 a = function() {};
-                console.log;
+                console.log(typeof a);
                 return a;
             }
         }());
     }
-    expect_stdout: "function"
+    expect_stdout: [
+        "function",
+        "function",
+    ]
 }
 
 issue_4115: {
@@ -2617,9 +2620,9 @@ issue_4126_1: {
             try {
                 console.log("PASS");
             } catch (e) {
-                var c = a;
+                var b = a;
             } finally {
-                var c = c;
+                var c = b;
             }
             console.log(c);
         }
@@ -2860,3 +2863,151 @@ issue_4155: {
         "function",
     ]
 }
+
+issue_4157_1: {
+    options = {
+        dead_code: true,
+        loops: true,
+        merge_vars: true,
+    }
+    input: {
+        (function() {
+            try {
+                for (var a = "FAIL"; a; a++)
+                    return;
+                var b = 0;
+            } finally {
+                console.log(b);
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            try {
+                var a = "FAIL";
+                if (a)
+                    return;
+                var b = 0;
+            } finally {
+                console.log(b);
+            }
+        })();
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4157_2: {
+    options = {
+        dead_code: true,
+        loops: true,
+        merge_vars: true,
+    }
+    input: {
+        (function() {
+            try {
+                throw "FAIL";
+            } catch (e) {
+                for (var a = e; a; a++)
+                    return;
+                var b = 0;
+            } finally {
+                console.log(b);
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            try {
+                throw "FAIL";
+            } catch (e) {
+                var a = e;
+                if (a)
+                    return;
+                var b = 0;
+            } finally {
+                console.log(b);
+            }
+        })();
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4168: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        var o = {
+            f: function(a, b, c) {
+                var d = a.d;
+                var e = b.e;
+                var f = c.f;
+                this.g(arguments);
+                if (d)
+                    console.log(e, f);
+            },
+            g: function(args) {
+                console.log(args[0], args[1], args[2]);
+            },
+        };
+        o.f("PASS", true, 42);
+    }
+    expect: {
+        var o = {
+            f: function(a, b, c) {
+                var d = a.d;
+                var e = b.e;
+                var f = c.f;
+                this.g(arguments);
+                if (d)
+                    console.log(e, f);
+            },
+            g: function(args) {
+                console.log(args[0], args[1], args[2]);
+            },
+        };
+        o.f("PASS", true, 42);
+    }
+    expect_stdout: "PASS true 42"
+}
+
+issue_4168_use_strict: {
+    options = {
+        merge_vars: true,
+    }
+    input: {
+        "use strict";
+        var o = {
+            f: function(a, b, c) {
+                var d = a.d;
+                var e = b.e;
+                var f = c.f;
+                this.g(arguments);
+                if (d)
+                    console.log(e, f);
+            },
+            g: function(args) {
+                console.log(args[0], args[1], args[2]);
+            },
+        };
+        o.f("PASS", true, 42);
+    }
+    expect: {
+        "use strict";
+        var o = {
+            f: function(d, e, f) {
+                var d = d.d;
+                var e = e.e;
+                var f = f.f;
+                this.g(arguments);
+                if (d)
+                    console.log(e, f);
+            },
+            g: function(args) {
+                console.log(args[0], args[1], args[2]);
+            },
+        };
+        o.f("PASS", true, 42);
+    }
+    expect_stdout: "PASS true 42"
+}

test/compress/properties.js

@@ -1123,11 +1123,7 @@ new_this: {
             }
         }.f(42);
     }
-    expect: {
+    expect: {}
-        new function(a) {
-            this.a = a;
-        }(42);
-    }
 }
 
 issue_2513: {

test/compress/reduce_vars.js

@@ -5374,11 +5374,11 @@ defun_catch_4: {
         try {
             throw 42;
         } catch (a) {
+            function a() {}
             console.log(a);
         }
     }
-    expect_stdout: "42"
+    expect_stdout: true
-    node_version: "<=4"
 }
 
 defun_catch_5: {
@@ -5400,10 +5400,10 @@ defun_catch_5: {
             throw 42;
         } catch (a) {
             console.log(a);
+            function a() {}
         }
     }
-    expect_stdout: "42"
+    expect_stdout: true
-    node_version: "<=4"
 }
 
 defun_catch_6: {
@@ -7535,3 +7535,69 @@ global_assign: {
     }
     expect_stdout: "PASS"
 }
+
+issue_4188_1: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            try {
+                while (A)
+                    var a = function() {}, b = a;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+        })();
+    }
+    expect: {
+        (function() {
+            try {
+                while (A)
+                    var a = function() {}, b = a;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+        })();
+    }
+    expect_stdout: "object undefined"
+}
+
+issue_4188_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        (function() {
+            try {
+                throw 42;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+            while (!console)
+                var a = function() {}, b = a;
+        })();
+    }
+    expect: {
+        (function() {
+            try {
+                throw 42;
+            } catch (a) {
+                console.log(function() {
+                    return typeof a;
+                }(), typeof b);
+            }
+            while (!console)
+                var a = function() {}, b = a;
+        })();
+    }
+    expect_stdout: "number undefined"
+}

test/compress/side_effects.js

@@ -416,3 +416,20 @@ issue_4008: {
         "PASS",
     ]
 }
+
+trim_new: {
+    options = {
+        side_effects: true,
+    }
+    input: {
+        new function(a) {
+            console.log(a);
+        }("PASS");
+    }
+    expect: {
+        (function(a) {
+            console.log(a);
+        })("PASS");
+    }
+    expect_stdout: "PASS"
+}

test/input/issue-3294/output.js

@@ -1,2 +1,2 @@
-new function(){console.log(3)};
+console.log(3);
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUErQyxJQUFyQyxXQUFnQkEsUUFBUUMsSUFBSSJ9
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUEwQkEsUUFBUUMsSUFBSSJ9

test/input/issue-520/output.js

@@ -1,2 +1,2 @@
-new function(){console.log(3)};
+console.log(3);
-//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUErQyxJQUFyQyxXQUFnQkEsUUFBUUMsSUFBSSJ9
+//# sourceMappingURL=data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sInNvdXJjZXNDb250ZW50IjpbImNsYXNzIEZvbyB7IGNvbnN0cnVjdG9yKCl7Y29uc29sZS5sb2coMSsyKTt9IH0gbmV3IEZvbygpO1xuIl0sIm5hbWVzIjpbImNvbnNvbGUiLCJsb2ciXSwibWFwcGluZ3MiOiJBQUEwQkEsUUFBUUMsSUFBSSJ9

test/mocha/number-literal.js

@@ -28,4 +28,65 @@ describe("Number literals", function() {
             assert.throws(test(inputs[i]), error, inputs[i]);
         }
     });
+    it("Should parse binary, hexadecimal, octal and underscore correctly", function() {
+        [
+            "42",
+            "4_2",
+            "052",
+            "0o52",
+            "0O52",
+            "0o5_2",
+            "0x2a",
+            "0X2A",
+            "0x2_a",
+            "0b101010",
+            "0B101010",
+            "0b101_010",
+            "0.0000000042e+10",
+            "0.0000000042E+10",
+            "0.0_000000042e+10",
+            "0.0000000042e+1_0",
+            "0.000_000_004_2e+1_0",
+            "0.000_000_004_2e+1_0-0B101_010+0x2_A-0o5_2+4_2",
+        ].forEach(function(code) {
+            var result = UglifyJS.minify(code, {
+                compress: {
+                    expression: true,
+                },
+            });
+            if (result.error) throw result.error;
+            assert.strictEqual(result.code, "42;");
+        });
+    });
+    it("Should reject invalid use of underscore", function() {
+        [
+            "_42",
+            "_+42",
+            "+_42",
+        ].forEach(function(code) {
+            var node = UglifyJS.parse(code, {
+                expression: true,
+            });
+            assert.ok(!node.is_constant(), code);
+            assert.ok(!(node instanceof UglifyJS.AST_Statement), code);
+        });
+        [
+            "42_",
+            "4__2",
+            "0_52",
+            "05_2",
+            "0_o52",
+            "0o_52",
+            "0.0000000042_e10",
+            "0.0000000042e_10",
+            "0.0000000042e_+10",
+            "0.0000000042e+_10",
+        ].forEach(function(code) {
+            assert.throws(function() {
+                UglifyJS.parse(code);
+            }, function(e) {
+                return e instanceof UglifyJS.JS_Parse_Error;
+            }, code);
+        });
+    });
 });

test/mocha/with.js

@@ -17,7 +17,7 @@ describe("With", function() {
         var ast = UglifyJS.parse("with(e) {f(1, 2)}");
         ast.figure_out_scope();
         assert.equal(ast.uses_with, true);
-        assert.equal(ast.body[0].expression.scope.uses_with, true);
+        assert.equal(ast.body[0].expression.scope.resolve().uses_with, true);
-        assert.equal(ast.body[0].body.body[0].body.expression.scope.uses_with, true);
+        assert.equal(ast.body[0].body.body[0].body.expression.scope.resolve().uses_with, true);
     });
 });

test/reduce.js

@@ -427,7 +427,7 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                     if (node.TYPE == "Call" && node.expression.print_to_string() == "console.log") {
                         return to_sequence(node.args);
                     }
-                    if (node instanceof U.AST_Catch) {
+                    if (node instanceof U.AST_Catch && node.argname) {
                         descend(node, this);
                         node.body.unshift(new U.AST_SimpleStatement({
                             body: wrap_with_console_log(new U.AST_SymbolRef(node.argname)),
@@ -499,7 +499,26 @@ module.exports = function reduce_test(testcase, minify_options, reduce_options)
                 log("// reduce test pass " + pass + ": " + testcase.length + " bytes");
             }
         }
-        testcase = try_beautify(testcase, minify_options, differs.unminified_result, result_cache, max_timeout);
+        var beautified = U.minify(testcase, {
+            compress: false,
+            mangle: false,
+            output: {
+                beautify: true,
+                braces: true,
+                comments: true,
+            },
+        });
+        testcase = {
+            code: testcase,
+        };
+        if (!beautified.error) {
+            diff = test_for_diff(beautified.code, minify_options, result_cache, max_timeout);
+            if (diff && !diff.timed_out && !diff.error) {
+                testcase = beautified;
+                testcase.code = "// (beautified)\n" + testcase.code;
+                differs = diff;
+            }
+        }
         var lines = [ "" ];
         if (isNaN(max_timeout)) {
             lines.push("// minify error: " + to_comment(strip_color_codes(differs.minified_result.stack)));
@@ -538,34 +557,6 @@ function trim_trailing_whitespace(value) {
     return ("" + value).replace(/\s+$/, "");
 }
 
-function try_beautify(testcase, minify_options, expected, result_cache, timeout) {
-    var result = U.minify(testcase, {
-        compress: false,
-        mangle: false,
-        output: {
-            beautify: true,
-            braces: true,
-            comments: true,
-        },
-    });
-    if (result.error) return {
-        code: testcase,
-    };
-    var toplevel = sandbox.has_toplevel(minify_options);
-    if (isNaN(timeout)) {
-        if (!U.minify(result.code, minify_options).error) return {
-            code: testcase,
-        };
-    } else {
-        var actual = run_code(result.code, toplevel, result_cache, timeout).result;
-        if (!sandbox.same_stdout(expected, actual)) return {
-            code: testcase,
-        };
-    }
-    result.code = "// (beautified)\n" + result.code;
-    return result;
-}
-
 function has_exit(fn) {
     var found = false;
     var tw = new U.TreeWalker(function(node) {

test/ufuzz/actions.js

@@ -38,6 +38,10 @@ exports.should_stop = function(callback) {
 };
 
 function read(url, callback) {
+    var done = function(reply) {
+        done = function() {};
+        callback(reply);
+    };
     var options = parse(url);
     options.headers = {
         "Authorization": "Token " + token,
@@ -49,7 +53,15 @@ function read(url, callback) {
         response.on("data", function(chunk) {
             chunks.push(chunk);
         }).on("end", function() {
-            callback(JSON.parse(chunks.join("")));
+            var reply;
+            try {
+                reply = JSON.parse(chunks.join(""))
+            } catch (e) {}
+            done(reply);
+        }).on("error", function() {
+            done();
         });
+    }).on("error", function() {
+        done();
     });
 }

test/ufuzz/job.js

@@ -57,7 +57,13 @@ function run() {
     function respawn() {
         console.log(stdout.replace(/[^\r\n]*\r/g, ""));
         clearInterval(log);
-        if (!iterations) spawn();
+        if (!iterations) {
+            spawn();
+        } else if (process.exitCode) {
+            tasks.forEach(function(kill) {
+                kill();
+            });
+        }
     }
 
     function trap(data) {