v3.11.1

closes #4171

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

@@ -412,33 +412,46 @@ 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_BlockScope = DEFNODE("BlockScope", "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",
-        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",
+        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.variables) node.variables = this.variables.clone();
-        if (this.functions) node.functions = this.functions.clone();
         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_Scope = DEFNODE("Scope", "cname 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)",
+        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",
+    },
     pinned: function() {
         return this.uses_eval || this.uses_with;
     },
-    _validate: function() {
-        if (this.parent_scope != null) {
-            if (!(this.parent_scope instanceof AST_Scope)) throw new Error("parent_scope must be AST_Scope");
-        }
-    },
-}, AST_Block);
+    resolve: return_this,
+}, AST_BlockScope);
 
 var AST_Toplevel = DEFNODE("Toplevel", "globals", {
     $documentation: "The toplevel scope",
@@ -703,7 +716,7 @@ var AST_Catch = DEFNODE("Catch", "argname", {
     _validate: function() {
         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"

lib/compress.js

@@ -1037,18 +1037,6 @@ 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) {
@@ -2150,7 +2138,9 @@ 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 +2243,7 @@ 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 +2313,21 @@ 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) {
@@ -4168,13 +4165,7 @@ merge(Compressor.prototype, {
             var scopes = [];
             self.walk(new TreeWalker(function(node, descend) {
                 if (!result) return true;
-                if (node instanceof AST_Catch) {
-                    scopes.push(node.argname.scope);
-                    descend();
-                    scopes.pop();
-                    return true;
-                }
-                if (node instanceof AST_Scope) {
+                if (node instanceof AST_BlockScope) {
                     if (node === self) return;
                     scopes.push(node);
                     descend();
@@ -4182,14 +4173,14 @@ 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";
@@ -4415,7 +4406,12 @@ 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 +4444,16 @@ merge(Compressor.prototype, {
                 push();
                 segment.block = node;
                 walk_body(node, tw);
+                pop();
                 if (node.bcatch) {
                     var def = node.bcatch.argname.definition();
                     references[def.id] = false;
                     if (def = def.redefined()) references[def.id] = false;
-                    pop();
                     push();
+                    if (node.bfinally) segment.block = node.bcatch;
                     walk_body(node.bcatch, tw);
+                    pop();
                 }
-                pop();
                 if (node.bfinally) node.bfinally.walk(tw);
                 return true;
             }
@@ -4482,6 +4479,7 @@ 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 +4790,15 @@ 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 +4851,8 @@ 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)
-                            && (!compressor.has_directive("use strict") || parent instanceof AST_Scope)) {
+                            && can_declare_defun()
+                            && 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 +4908,13 @@ 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:
@@ -5163,6 +5168,13 @@ merge(Compressor.prototype, {
                 if (!(node_def.id in in_use_ids)) {
                     in_use_ids[node_def.id] = true;
                     in_use.push(node_def);
+                    if (node.scope !== node_def.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 +5403,7 @@ 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);
@@ -6804,7 +6816,7 @@ 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(compressor.find_parent(AST_BlockScope)))
                 && (value = can_flatten_body(stat))
                 && !fn.contains_this()) {
                 var replacing = exp === fn || compressor.option("unused") && def.references.length - def.replaced == 1;
@@ -6830,7 +6842,7 @@ 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);
@@ -7046,9 +7058,10 @@ 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 +7082,12 @@ 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();
@@ -8065,7 +8083,9 @@ merge(Compressor.prototype, {
                         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
+                        || !(self.scope instanceof AST_Scope)
+                        || def.orig[0] instanceof AST_SymbolFunarg) {
                         single_use = fixed.is_constant_expression(self.scope);
                         if (single_use == "f") {
                             var scope = self.scope;
@@ -8213,7 +8233,7 @@ merge(Compressor.prototype, {
 
     OPT(AST_Undefined, function(self, compressor) {
         if (compressor.option("unsafe_undefined")) {
-            var undef = find_variable(compressor, "undefined");
+            var undef = compressor.find_parent(AST_BlockScope).find_variable("undefined");
             if (undef) {
                 var ref = make_node(AST_SymbolRef, self, {
                     name   : "undefined",
@@ -8239,7 +8259,7 @@ 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"))
+            && !compressor.find_parent(AST_BlockScope).find_variable("Infinity"))
             return self;
         return make_node(AST_Binary, self, {
             operator: "/",
@@ -8255,7 +8275,7 @@ merge(Compressor.prototype, {
     OPT(AST_NaN, function(self, compressor) {
         var lhs = is_lhs(compressor.self(), compressor.parent());
         if (lhs && !is_atomic(lhs, self)
-            || find_variable(compressor, "NaN")) {
+            || compressor.find_parent(AST_BlockScope).find_variable("NaN")) {
             return make_node(AST_Binary, self, {
                 operator: "/",
                 left: make_node(AST_Number, self, {

lib/scope.js

@@ -59,13 +59,9 @@ function SymbolDef(id, scope, orig, init) {
 }
 
 SymbolDef.prototype = {
-    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);
+    forEach: function(fn) {
+        this.orig.forEach(fn);
+        this.references.forEach(fn);
     },
     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) {
@@ -100,22 +104,18 @@ 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) {
-            var save_scope = scope;
-            scope = new AST_Scope(node);
-            scope.init_scope_vars(save_scope);
-            descend();
-            scope = save_scope;
+        if (node instanceof AST_Defun) {
+            node.name.walk(tw);
+            walk_scope(function() {
+                node.argnames.forEach(function(argname) {
+                    argname.walk(tw);
+                });
+                walk_body(node, tw);
+            });
             return true;
         }
-        if (node instanceof AST_Scope) {
-            node.init_scope_vars(scope);
-            var save_scope = scope;
-            var save_defun = defun;
-            defun = scope = node;
-            descend();
-            scope = save_scope;
-            defun = save_defun;
+        if (node instanceof AST_BlockScope) {
+            walk_scope(descend);
             return true;
         }
         if (node instanceof AST_With) {
@@ -129,25 +129,41 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options) {
             node.thedef = node;
             node.references = [];
         }
-        if (node instanceof AST_SymbolDefun) {
-            // This should be defined in the parent scope, as we encounter the
-            // AST_Defun node before getting to its AST_Symbol.
-            (node.scope = defun.parent_scope.resolve()).def_function(node, defun);
+        if (node instanceof AST_SymbolCatch) {
+            scope.def_variable(node).defun = defun;
+        } else if (node instanceof AST_SymbolDefun) {
+            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);
-            if (defun !== scope) {
-                node.mark_enclosed(options);
-                var def = scope.find_variable(node);
-                if (node.thedef !== def) {
-                    node.thedef = def;
-                }
-                node.reference(options);
-            }
-        } else if (node instanceof AST_SymbolCatch) {
-            scope.def_variable(node).defun = defun;
+            defun.def_variable(node, null);
+            entangle(defun, scope);
+        }
+
+        function walk_scope(descend) {
+            node.init_scope_vars(scope);
+            var save_defun = defun;
+            var save_scope = scope;
+            if (node instanceof AST_Scope) defun = node;
+            scope = node;
+            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) {
@@ -234,7 +250,8 @@ 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);
         });
@@ -267,7 +284,7 @@ function init_scope_vars(scope, parent) {
     if (parent) scope.make_def = parent.make_def;   // top-level tracking of SymbolDef instances
 }
 
-AST_Scope.DEFMETHOD("init_scope_vars", function(parent_scope) {
+AST_BlockScope.DEFMETHOD("init_scope_vars", function(parent_scope) {
     init_scope_vars(this, parent_scope);
 });
 
@@ -300,20 +317,20 @@ 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 +343,6 @@ 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 +364,7 @@ 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) {
@@ -495,8 +506,7 @@ 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_SymbolCatch) add_def(node.definition());
+        if (node instanceof AST_BlockScope) node.variables.each(add_def);
     }));
     return avoid;
 
@@ -520,8 +530,7 @@ 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_SymbolCatch) rename(node.definition());
+        if (node instanceof AST_BlockScope) node.variables.each(rename);
     }));
 
     function next_name() {
@@ -539,7 +548,7 @@ 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;
         });
     }

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": "3.11.1",
   "engines": {
     "node": ">=0.8.0"
   },

test/compress/drop-unused.js

@@ -2992,3 +2992,34 @@ issue_4146: {
     }
     expect_stdout: "function"
 }
+
+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
+}

test/compress/functions.js

@@ -4808,3 +4808,182 @@ 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
+}

test/compress/ie8.js

@@ -2714,3 +2714,108 @@ 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
+}

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/merge_vars.js

@@ -2617,9 +2617,9 @@ 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 +2860,151 @@ 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/reduce_vars.js

@@ -5374,11 +5374,11 @@ defun_catch_4: {
         try {
             throw 42;
         } catch (a) {
+            function a() {}
             console.log(a);
         }
     }
-    expect_stdout: "42"
-    node_version: "<=4"
+    expect_stdout: true
 }
 
 defun_catch_5: {
@@ -5400,10 +5400,10 @@ defun_catch_5: {
             throw 42;
         } catch (a) {
             console.log(a);
+            function a() {}
         }
     }
-    expect_stdout: "42"
-    node_version: "<=4"
+    expect_stdout: true
 }
 
 defun_catch_6: {

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) {