v3.0.23

... by teaching `collapse_vars` some new tricks.

fixes #2187

README.md

@@ -111,7 +111,7 @@ a double dash to prevent input files being used as option arguments:
                                 By default UglifyJS will not try to be IE-proof.
     --keep-fnames               Do not mangle/drop function names.  Useful for
                                 code relying on Function.prototype.name.
-    --name-cache                File to hold mangled name mappings.
+    --name-cache <file>         File to hold mangled name mappings.
     --self                      Build UglifyJS as a library (implies --wrap UglifyJS)
     --source-map [options]      Enable source map/specify source map options:
                                 `base`  Path to compute relative paths from input files.
@@ -383,7 +383,47 @@ var code = {
 var options = { toplevel: true };
 var result = UglifyJS.minify(code, options);
 console.log(result.code);
-// console.log(function(n,o){return n+o}(3,7));
+// console.log(3+7);
+```
+
+The `nameCache` option:
+```javascript
+var options = {
+    mangle: {
+        toplevel: true,
+    },
+    nameCache: {}
+};
+var result1 = UglifyJS.minify({
+    "file1.js": "function add(first, second) { return first + second; }"
+}, options);
+var result2 = UglifyJS.minify({
+    "file2.js": "console.log(add(1 + 2, 3 + 4));"
+}, options);
+console.log(result1.code);
+// function n(n,r){return n+r}
+console.log(result2.code);
+// console.log(n(3,7));
+```
+
+You may persist the name cache to the file system in the following way:
+```javascript
+var cacheFileName = "/tmp/cache.json";
+var options = {
+    mangle: {
+        properties: true,
+    },
+    nameCache: JSON.parse(fs.readFileSync(cacheFileName, "utf8"))
+};
+fs.writeFileSync("part1.js", UglifyJS.minify({
+    "file1.js": fs.readFileSync("file1.js", "utf8"),
+    "file2.js": fs.readFileSync("file2.js", "utf8")
+}, options).code, "utf8");
+fs.writeFileSync("part2.js", UglifyJS.minify({
+    "file3.js": fs.readFileSync("file3.js", "utf8"),
+    "file4.js": fs.readFileSync("file4.js", "utf8")
+}, options).code, "utf8");
+fs.writeFileSync(cacheFileName, JSON.stringify(options.nameCache), "utf8");
 ```
 
 An example of a combination of `minify()` options:
@@ -461,6 +501,13 @@ if (result.error) throw result.error;
 - `toplevel` (default `false`) - set to `true` if you wish to enable top level
   variable and function name mangling and to drop unused variables and functions.
 
+- `nameCache` (default `null`) - pass an empty object `{}` or a previously
+  used `nameCache` object if you wish to cache mangled variable and
+  property names across multiple invocations of `minify()`. Note: this is
+  a read/write property. `minify()` will read the name cache state of this
+  object and update it during minification so that it may be
+  reused or externally persisted by the user.
+
 - `ie8` (default `false`) - set to `true` to support IE8.
 
 ## Minify options structure
@@ -487,6 +534,7 @@ if (result.error) throw result.error;
     sourceMap: {
         // source map options
     },
+    nameCache: null, // or specify a name cache object
     toplevel: false,
     ie8: false,
 }

bin/uglifyjs

@@ -106,17 +106,8 @@ if (program.mangleProps) {
     if (typeof options.mangle != "object") options.mangle = {};
     options.mangle.properties = program.mangleProps;
 }
-var cache;
 if (program.nameCache) {
-    cache = JSON.parse(read_file(program.nameCache, "{}"));
+    options.nameCache = JSON.parse(read_file(program.nameCache, "{}"));
-    if (options.mangle) {
-        if (typeof options.mangle != "object") options.mangle = {};
-        options.mangle.cache = to_cache("vars");
-        if (options.mangle.properties) {
-            if (typeof options.mangle.properties != "object") options.mangle.properties = {};
-            options.mangle.properties.cache = to_cache("props");
-        }
-    }
 }
 if (program.output == "ast") {
     options.output = {
@@ -266,9 +257,7 @@ function run() {
         print(result.code);
     }
     if (program.nameCache) {
-        fs.writeFileSync(program.nameCache, JSON.stringify(cache, function(key, value) {
+        fs.writeFileSync(program.nameCache, JSON.stringify(options.nameCache));
-            return value instanceof UglifyJS.Dictionary ? value.toObject() : value;
-        }));
     }
     if (result.timings) for (var phase in result.timings) {
         print_error("- " + phase + ": " + result.timings[phase].toFixed(3) + "s");
@@ -381,18 +370,6 @@ function parse_source_map() {
     }
 }
 
-function to_cache(key) {
-    if (cache[key]) {
-        cache[key].props = UglifyJS.Dictionary.fromObject(cache[key].props);
-    } else {
-        cache[key] = {
-            cname: -1,
-            props: new UglifyJS.Dictionary()
-        };
-    }
-    return cache[key];
-}
-
 function skip_key(key) {
     return skip_keys.indexOf(key) >= 0;
 }

lib/compress.js

@@ -92,12 +92,9 @@ function Compressor(options, false_by_default) {
     var global_defs = this.options["global_defs"];
     if (typeof global_defs == "object") for (var key in global_defs) {
         if (/^@/.test(key) && HOP(global_defs, key)) {
-            var ast = parse(global_defs[key]);
+            global_defs[key.slice(1)] = parse(global_defs[key], {
-            if (ast.body.length == 1 && ast.body[0] instanceof AST_SimpleStatement) {
+                expression: true
-                global_defs[key.slice(1)] = ast.body[0].body;
+            });
-            } else throw new Error(string_template("Can't handle expression: {value}", {
-                value: global_defs[key]
-            }));
         }
     }
     var pure_funcs = this.options["pure_funcs"];
@@ -124,13 +121,13 @@ function Compressor(options, false_by_default) {
         };
     }
     var toplevel = this.options["toplevel"];
-    if (typeof toplevel == "string") {
+    this.toplevel = typeof toplevel == "string" ? {
-        this.toplevel.funcs = /funcs/.test(toplevel);
+        funcs: /funcs/.test(toplevel),
-        this.toplevel.vars = /vars/.test(toplevel);
+        vars: /vars/.test(toplevel)
-    } else {
+    } : {
-        this.toplevel = toplevel ? return_true : return_false;
+        funcs: toplevel,
-        this.toplevel.funcs = this.toplevel.vars = toplevel;
+        vars: toplevel
-    }
+    };
     var sequences = this.options["sequences"];
     this.sequences_limit = sequences == 1 ? 800 : sequences | 0;
     this.warnings_produced = {};
@@ -139,11 +136,11 @@ function Compressor(options, false_by_default) {
 Compressor.prototype = new TreeTransformer;
 merge(Compressor.prototype, {
     option: function(key) { return this.options[key] },
-    toplevel: function(def) {
+    exposed: function(def) {
-        for (var i = 0, len = def.orig.length; i < len; i++)
+        if (def.global) for (var i = 0, len = def.orig.length; i < len; i++)
             if (!this.toplevel[def.orig[i] instanceof AST_SymbolDefun ? "funcs" : "vars"])
-                return false;
+                return true;
-        return true;
+        return false;
     },
     compress: function(node) {
         if (this.option("expression")) {
@@ -279,11 +276,11 @@ merge(Compressor.prototype, {
         var reduce_vars = rescan && compressor.option("reduce_vars");
         var safe_ids = Object.create(null);
         var suppressor = new TreeWalker(function(node) {
-            if (node instanceof AST_Symbol) {
+            if (!(node instanceof AST_Symbol)) return;
-                var d = node.definition();
+            var d = node.definition();
-                if (node instanceof AST_SymbolRef) d.references.push(node);
+            if (!d) return;
-                d.fixed = false;
+            if (node instanceof AST_SymbolRef) d.references.push(node);
-            }
+            d.fixed = false;
         });
         var tw = new TreeWalker(function(node, descend) {
             node._squeezed = false;
@@ -345,7 +342,7 @@ merge(Compressor.prototype, {
                 }
                 if (node instanceof AST_Defun) {
                     var d = node.name.definition();
-                    if (d.global && !compressor.toplevel(d) || safe_to_read(d)) {
+                    if (compressor.exposed(d) || safe_to_read(d)) {
                         d.fixed = false;
                     } else {
                         d.fixed = node;
@@ -517,7 +514,7 @@ merge(Compressor.prototype, {
             def.escaped = false;
             if (def.scope.uses_eval) {
                 def.fixed = false;
-            } else if (!def.global || compressor.toplevel(def)) {
+            } else if (!compressor.exposed(def)) {
                 def.fixed = undefined;
             } else {
                 def.fixed = false;
@@ -547,8 +544,25 @@ merge(Compressor.prototype, {
         return fixed();
     });
 
+    AST_SymbolRef.DEFMETHOD("is_immutable", function() {
+        var orig = this.definition().orig;
+        return orig.length == 1 && orig[0] instanceof AST_SymbolLambda;
+    });
+
     function is_lhs_read_only(lhs) {
-        return lhs instanceof AST_SymbolRef && lhs.definition().orig[0] instanceof AST_SymbolLambda;
+        if (lhs instanceof AST_SymbolRef) return lhs.definition().orig[0] instanceof AST_SymbolLambda;
+        if (lhs instanceof AST_PropAccess) {
+            lhs = lhs.expression;
+            if (lhs instanceof AST_SymbolRef) {
+                if (lhs.is_immutable()) return false;
+                lhs = lhs.fixed_value();
+            }
+            if (!lhs) return true;
+            if (lhs instanceof AST_RegExp) return false;
+            if (lhs instanceof AST_Constant) return true;
+            return is_lhs_read_only(lhs);
+        }
+        return false;
     }
 
     function find_variable(compressor, name) {
@@ -668,26 +682,24 @@ merge(Compressor.prototype, {
         var CHANGED, max_iter = 10;
         do {
             CHANGED = false;
-            statements = eliminate_spurious_blocks(statements);
+            eliminate_spurious_blocks(statements);
             if (compressor.option("dead_code")) {
-                statements = eliminate_dead_code(statements, compressor);
+                eliminate_dead_code(statements, compressor);
             }
             if (compressor.option("if_return")) {
-                statements = handle_if_return(statements, compressor);
+                handle_if_return(statements, compressor);
             }
             if (compressor.sequences_limit > 0) {
-                statements = sequencesize(statements, compressor);
+                sequencesize(statements, compressor);
             }
             if (compressor.option("join_vars")) {
-                statements = join_consecutive_vars(statements, compressor);
+                join_consecutive_vars(statements, compressor);
             }
             if (compressor.option("collapse_vars")) {
-                statements = collapse(statements, compressor);
+                collapse(statements, compressor);
             }
         } while (CHANGED && max_iter-- > 0);
 
-        return statements;
-
         // Search from right to left for assignment-like expressions:
         // - `var a = x;`
         // - `a = x;`
@@ -702,15 +714,23 @@ merge(Compressor.prototype, {
             var candidates = [];
             var stat_index = statements.length;
             while (--stat_index >= 0) {
+                // Treat parameters as collapsible in IIFE, i.e.
+                //   function(a, b){ ... }(x());
+                // would be translated into equivalent assignments:
+                //   var a = x(), b = undefined;
+                if (stat_index == 0 && compressor.option("unused")) extract_args();
+                // Find collapsible assignments
                 extract_candidates(statements[stat_index]);
                 while (candidates.length > 0) {
                     var candidate = candidates.pop();
                     var lhs = get_lhs(candidate);
                     if (!lhs || is_lhs_read_only(lhs)) continue;
+                    // Locate symbols which may execute code outside of scanning range
                     var lvalues = get_lvalues(candidate);
                     if (lhs instanceof AST_SymbolRef) lvalues[lhs.name] = false;
                     var side_effects = value_has_side_effects(candidate);
-                    var hit = false, abort = false, replaced = false;
+                    var hit = candidate.name instanceof AST_SymbolFunarg;
+                    var abort = false, replaced = false;
                     var tt = new TreeTransformer(function(node, descend) {
                         if (abort) return node;
                         // Skip nodes before `candidate` as quickly as possible
@@ -724,6 +744,7 @@ merge(Compressor.prototype, {
                         // Stop immediately if these node types are encountered
                         var parent = tt.parent();
                         if (node instanceof AST_Assign && node.operator != "=" && lhs.equivalent_to(node.left)
+                            || node instanceof AST_Call && lhs instanceof AST_PropAccess && lhs.equivalent_to(node.expression)
                             || node instanceof AST_Debugger
                             || node instanceof AST_IterationStatement && !(node instanceof AST_For)
                             || node instanceof AST_SymbolRef && node.undeclared()
@@ -749,7 +770,7 @@ merge(Compressor.prototype, {
                             }
                             if (candidate instanceof AST_VarDef) {
                                 var def = candidate.name.definition();
-                                if (def.references.length == 1 && (!def.global || compressor.toplevel(def))) {
+                                if (def.references.length == 1 && !compressor.exposed(def)) {
                                     return maintain_this_binding(parent, node, candidate.value);
                                 }
                                 return make_node(AST_Assign, candidate, {
@@ -789,7 +810,35 @@ merge(Compressor.prototype, {
                     if (replaced && !remove_candidate(candidate)) statements.splice(stat_index, 1);
                 }
             }
-            return statements;
+
+            function extract_args() {
+                var iife, fn = compressor.self();
+                if (fn instanceof AST_Function
+                    && !fn.name
+                    && !fn.uses_arguments
+                    && !fn.uses_eval
+                    && (iife = compressor.parent()) instanceof AST_Call
+                    && iife.expression === fn) {
+                    fn.argnames.forEach(function(sym, i) {
+                        var arg = iife.args[i];
+                        if (!arg) arg = make_node(AST_Undefined, sym);
+                        else arg.walk(new TreeWalker(function(node) {
+                            if (!arg) return true;
+                            if (node instanceof AST_SymbolRef && fn.variables.has(node.name)) {
+                                var s = node.definition().scope;
+                                if (s !== scope) while (s = s.parent_scope) {
+                                    if (s === scope) return true;
+                                }
+                                arg = null;
+                            }
+                        }));
+                        if (arg) candidates.push(make_node(AST_VarDef, sym, {
+                            name: sym,
+                            value: arg
+                        }));
+                    });
+                }
+            }
 
             function extract_candidates(expr) {
                 if (expr instanceof AST_Assign && !expr.left.has_side_effects(compressor)
@@ -811,8 +860,8 @@ merge(Compressor.prototype, {
             function get_lhs(expr) {
                 if (expr instanceof AST_VarDef) {
                     var def = expr.name.definition();
-                    if (def.orig.length > 1
+                    if (def.orig.length > 1 && !(expr.name instanceof AST_SymbolFunarg)
-                        || def.references.length == 1 && (!def.global || compressor.toplevel(def))) {
+                        || def.references.length == 1 && !compressor.exposed(def)) {
                         return make_node(AST_SymbolRef, expr.name, expr.name);
                     }
                 } else {
@@ -853,6 +902,14 @@ merge(Compressor.prototype, {
             }
 
             function remove_candidate(expr) {
+                if (expr.name instanceof AST_SymbolFunarg) {
+                    var index = compressor.self().argnames.indexOf(expr.name);
+                    var args = compressor.parent().args;
+                    if (args[index]) args[index] = make_node(AST_Number, args[index], {
+                        value: 0
+                    });
+                    return true;
+                }
                 var found = false;
                 return statements[stat_index].transform(new TreeTransformer(function(node, descend, in_list) {
                     if (found) return node;
@@ -891,59 +948,60 @@ merge(Compressor.prototype, {
 
         function eliminate_spurious_blocks(statements) {
             var seen_dirs = [];
-            return statements.reduce(function(a, stat){
+            for (var i = 0; i < statements.length;) {
+                var stat = statements[i];
                 if (stat instanceof AST_BlockStatement) {
                     CHANGED = true;
-                    a.push.apply(a, eliminate_spurious_blocks(stat.body));
+                    eliminate_spurious_blocks(stat.body);
+                    [].splice.apply(statements, [i, 1].concat(stat.body));
+                    i += stat.body.length;
                 } else if (stat instanceof AST_EmptyStatement) {
                     CHANGED = true;
+                    statements.splice(i, 1);
                 } else if (stat instanceof AST_Directive) {
                     if (seen_dirs.indexOf(stat.value) < 0) {
-                        a.push(stat);
+                        i++;
                         seen_dirs.push(stat.value);
                     } else {
                         CHANGED = true;
+                        statements.splice(i, 1);
                     }
-                } else {
+                } else i++;
-                    a.push(stat);
+            }
-                }
+        }
-                return a;
-            }, []);
-        };
 
         function handle_if_return(statements, compressor) {
             var self = compressor.self();
             var multiple_if_returns = has_multiple_if_returns(statements);
             var in_lambda = self instanceof AST_Lambda;
-            var ret = []; // Optimized statements, build from tail to front
+            for (var i = statements.length; --i >= 0;) {
-            loop: for (var i = statements.length; --i >= 0;) {
                 var stat = statements[i];
-                switch (true) {
+                var next = statements[i + 1];
-                  case (in_lambda && stat instanceof AST_Return && !stat.value && ret.length == 0):
+
+                if (in_lambda && stat instanceof AST_Return && !stat.value && !next) {
                     CHANGED = true;
-                    // note, ret.length is probably always zero
+                    statements.length--;
-                    // because we drop unreachable code before this
+                    continue;
-                    // step.  nevertheless, it's good to check.
+                }
-                    continue loop;
+
-                  case stat instanceof AST_If:
+                if (stat instanceof AST_If) {
                     var ab = aborts(stat.body);
                     if (can_merge_flow(ab)) {
                         if (ab.label) {
                             remove(ab.label.thedef.references, ab);
                         }
                         CHANGED = true;
-                        var funs = extract_functions_from_statement_array(ret);
-                        var body = as_statement_array_with_return(stat.body, ab);
                         stat = stat.clone();
                         stat.condition = stat.condition.negate(compressor);
+                        var body = as_statement_array_with_return(stat.body, ab);
                         stat.body = make_node(AST_BlockStatement, stat, {
-                            body: as_statement_array(stat.alternative).concat(ret)
+                            body: as_statement_array(stat.alternative).concat(extract_functions())
                         });
                         stat.alternative = make_node(AST_BlockStatement, stat, {
                             body: body
                         });
-                        ret = [ stat.transform(compressor) ].concat(funs);
+                        statements[i] = stat.transform(compressor);
-                        continue loop;
+                        continue;
                     }
 
                     var ab = aborts(stat.alternative);
@@ -952,81 +1010,71 @@ merge(Compressor.prototype, {
                             remove(ab.label.thedef.references, ab);
                         }
                         CHANGED = true;
-                        var funs = extract_functions_from_statement_array(ret);
                         stat = stat.clone();
                         stat.body = make_node(AST_BlockStatement, stat.body, {
-                            body: as_statement_array(stat.body).concat(ret)
+                            body: as_statement_array(stat.body).concat(extract_functions())
                         });
                         var body = as_statement_array_with_return(stat.alternative, ab);
                         stat.alternative = make_node(AST_BlockStatement, stat.alternative, {
                             body: body
                         });
-                        ret = [ stat.transform(compressor) ].concat(funs);
+                        statements[i] = stat.transform(compressor);
-                        continue loop;
+                        continue;
                     }
+                }
 
-                    if (stat.body instanceof AST_Return) {
+                if (stat instanceof AST_If && stat.body instanceof AST_Return) {
-                        var value = stat.body.value;
+                    var value = stat.body.value;
-                        //---
+                    //---
-                        // pretty silly case, but:
+                    // pretty silly case, but:
-                        // if (foo()) return; return; ==> foo(); return;
+                    // if (foo()) return; return; ==> foo(); return;
-                        if ((in_lambda && ret.length == 0 || ret[0] instanceof AST_Return && !ret[0].value)
+                    if (!value && !stat.alternative
-                            && !value && !stat.alternative) {
+                        && (in_lambda && !next || next instanceof AST_Return && !next.value)) {
-                            CHANGED = true;
+                        CHANGED = true;
-                            var cond = make_node(AST_SimpleStatement, stat.condition, {
+                        statements[i] = make_node(AST_SimpleStatement, stat.condition, {
-                                body: stat.condition
+                            body: stat.condition
-                            });
+                        });
-                            ret.unshift(cond);
+                        continue;
-                            continue loop;
+                    }
-                        }
+                    //---
-                        //---
+                    // if (foo()) return x; return y; ==> return foo() ? x : y;
-                        // if (foo()) return x; return y; ==> return foo() ? x : y;
+                    if (value && !stat.alternative && next instanceof AST_Return && next.value) {
-                        if (ret[0] instanceof AST_Return && value && ret[0].value && !stat.alternative) {
+                        CHANGED = true;
-                            CHANGED = true;
+                        stat = stat.clone();
-                            stat = stat.clone();
+                        stat.alternative = next;
-                            stat.alternative = ret[0];
+                        statements.splice(i, 2, stat.transform(compressor));
-                            ret[0] = stat.transform(compressor);
+                        continue;
-                            continue loop;
+                    }
-                        }
+                    //---
-                        //---
+                    // if (foo()) return x; [ return ; ] ==> return foo() ? x : undefined;
-                        // if (foo()) return x; [ return ; ] ==> return foo() ? x : undefined;
+                    if (multiple_if_returns && in_lambda && value && !stat.alternative
-                        if (multiple_if_returns && (ret.length == 0 || ret[0] instanceof AST_Return)
+                        && (!next || next instanceof AST_Return)) {
-                            && value && !stat.alternative && in_lambda) {
+                        CHANGED = true;
-                            CHANGED = true;
+                        stat = stat.clone();
-                            stat = stat.clone();
+                        stat.alternative = next || make_node(AST_Return, stat, {
-                            stat.alternative = ret[0] || make_node(AST_Return, stat, {
+                            value: null
-                                value: null
+                        });
-                            });
+                        statements.splice(i, next ? 2 : 1, stat.transform(compressor));
-                            ret[0] = stat.transform(compressor);
+                        continue;
-                            continue loop;
+                    }
-                        }
+                    //---
-                        //---
+                    // if (a) return b; if (c) return d; e; ==> return a ? b : c ? d : void e;
-                        // if (a) return b; if (c) return d; e; ==> return a ? b : c ? d : void e;
+                    //
-                        //
+                    // if sequences is not enabled, this can lead to an endless loop (issue #866).
-                        // if sequences is not enabled, this can lead to an endless loop (issue #866).
+                    // however, with sequences on this helps producing slightly better output for
-                        // however, with sequences on this helps producing slightly better output for
+                    // the example code.
-                        // the example code.
+                    var prev = statements[i - 1];
-                        if (compressor.option("sequences")
+                    if (compressor.option("sequences") && in_lambda && !stat.alternative
-                            && i > 0 && statements[i - 1] instanceof AST_If && statements[i - 1].body instanceof AST_Return
+                        && prev instanceof AST_If && prev.body instanceof AST_Return
-                            && ret.length == 1 && in_lambda && ret[0] instanceof AST_SimpleStatement
+                        && i + 2 == statements.length && next instanceof AST_SimpleStatement) {
-                            && !stat.alternative) {
+                        CHANGED = true;
-                            CHANGED = true;
+                        statements.push(make_node(AST_Return, next, {
-                            ret.push(make_node(AST_Return, ret[0], {
+                            value: null
-                                value: null
+                        }).transform(compressor));
-                            }).transform(compressor));
+                        continue;
-                            ret.unshift(stat);
-                            continue loop;
-                        }
                     }
-
-                    ret.unshift(stat);
-                    break;
-                  default:
-                    ret.unshift(stat);
-                    break;
                 }
             }
-            return ret;
 
             function has_multiple_if_returns(statements) {
                 var n = 0;
@@ -1051,6 +1099,18 @@ merge(Compressor.prototype, {
                     || ab instanceof AST_Break && lct instanceof AST_BlockStatement && self === lct;
             }
 
+            function extract_functions() {
+                var tail = statements.slice(i + 1);
+                statements.length = i + 1;
+                return tail.filter(function(stat) {
+                    if (stat instanceof AST_Defun) {
+                        statements.push(stat);
+                        return false;
+                    }
+                    return true;
+                });
+            }
+
             function as_statement_array_with_return(node, ab) {
                 var body = as_statement_array(node).slice(0, -1);
                 if (ab.value) {
@@ -1060,49 +1120,52 @@ merge(Compressor.prototype, {
                 }
                 return body;
             }
-        };
+        }
 
         function eliminate_dead_code(statements, compressor) {
-            var has_quit = false;
+            var has_quit;
-            var orig = statements.length;
             var self = compressor.self();
-            statements = statements.reduce(function(a, stat){
+            for (var i = 0, n = 0, len = statements.length; i < len; i++) {
-                if (has_quit) {
+                var stat = statements[i];
-                    extract_declarations_from_unreachable_code(compressor, stat, a);
+                if (stat instanceof AST_LoopControl) {
-                } else {
+                    var lct = compressor.loopcontrol_target(stat);
-                    if (stat instanceof AST_LoopControl) {
+                    if (stat instanceof AST_Break
-                        var lct = compressor.loopcontrol_target(stat);
+                            && !(lct instanceof AST_IterationStatement)
-                        if ((stat instanceof AST_Break
+                            && loop_body(lct) === self
-                             && !(lct instanceof AST_IterationStatement)
+                        || stat instanceof AST_Continue
-                             && loop_body(lct) === self) || (stat instanceof AST_Continue
+                            && loop_body(lct) === self) {
-                                                             && loop_body(lct) === self)) {
+                        if (stat.label) {
-                            if (stat.label) {
+                            remove(stat.label.thedef.references, stat);
-                                remove(stat.label.thedef.references, stat);
-                            }
-                        } else {
-                            a.push(stat);
                         }
                     } else {
-                        a.push(stat);
+                        statements[n++] = stat;
                     }
-                    if (aborts(stat)) has_quit = true;
+                } else {
+                    statements[n++] = stat;
                 }
-                return a;
+                if (aborts(stat)) {
-            }, []);
+                    has_quit = statements.slice(i + 1);
-            CHANGED = statements.length != orig;
+                    break;
-            return statements;
+                }
-        };
+            }
+            statements.length = n;
+            CHANGED = n != len;
+            if (has_quit) has_quit.forEach(function(stat) {
+                extract_declarations_from_unreachable_code(compressor, stat, statements);
+            });
+        }
 
         function sequencesize(statements, compressor) {
-            if (statements.length < 2) return statements;
+            if (statements.length < 2) return;
-            var seq = [], ret = [];
+            var seq = [], n = 0;
             function push_seq() {
                 if (!seq.length) return;
                 var body = make_sequence(seq[0], seq);
-                ret.push(make_node(AST_SimpleStatement, body, { body: body }));
+                statements[n++] = make_node(AST_SimpleStatement, body, { body: body });
                 seq = [];
-            };
+            }
-            statements.forEach(function(stat){
+            for (var i = 0, len = statements.length; i < len; i++) {
+                var stat = statements[i];
                 if (stat instanceof AST_SimpleStatement) {
                     if (seq.length >= compressor.sequences_limit) push_seq();
                     var body = stat.body;
@@ -1110,18 +1173,18 @@ merge(Compressor.prototype, {
                     if (body) merge_sequence(seq, body);
                 } else {
                     push_seq();
-                    ret.push(stat);
+                    statements[n++] = stat;
                 }
-            });
+            }
             push_seq();
-            ret = sequencesize_2(ret, compressor);
+            statements.length = n;
-            CHANGED = ret.length != statements.length;
+            sequencesize_2(statements, compressor);
-            return ret;
+            CHANGED = statements.length != len;
-        };
+        }
 
         function sequencesize_2(statements, compressor) {
             function cons_seq(right) {
-                ret.pop();
+                n--;
                 var left = prev.body;
                 if (!(left instanceof AST_Sequence)) {
                     left = make_node(AST_Sequence, left, {
@@ -1131,8 +1194,9 @@ merge(Compressor.prototype, {
                 merge_sequence(left.expressions, right);
                 return left.transform(compressor);
             };
-            var ret = [], prev = null;
+            var n = 0, prev;
-            statements.forEach(function(stat){
+            for (var i = 0, len = statements.length; i < len; i++) {
+                var stat = statements[i];
                 if (prev) {
                     if (stat instanceof AST_For) {
                         try {
@@ -1145,7 +1209,7 @@ merge(Compressor.prototype, {
                             }
                             else if (!stat.init) {
                                 stat.init = prev.body.drop_side_effect_free(compressor);
-                                ret.pop();
+                                n--;
                             }
                         } catch(ex) {
                             if (ex !== cons_seq) throw ex;
@@ -1167,15 +1231,16 @@ merge(Compressor.prototype, {
                         stat.expression = cons_seq(stat.expression);
                     }
                 }
-                ret.push(stat);
+                statements[n++] = stat;
                 prev = stat instanceof AST_SimpleStatement ? stat : null;
-            });
+            }
-            return ret;
+            statements.length = n;
-        };
+        }
 
         function join_consecutive_vars(statements, compressor) {
-            var prev = null;
+            for (var i = 0, j = -1, len = statements.length; i < len; i++) {
-            return statements.reduce(function(a, stat){
+                var stat = statements[i];
+                var prev = statements[j];
                 if (stat instanceof AST_Definitions && prev && prev.TYPE == stat.TYPE) {
                     prev.definitions = prev.definitions.concat(stat.definitions);
                     CHANGED = true;
@@ -1184,35 +1249,19 @@ merge(Compressor.prototype, {
                          && prev instanceof AST_Var
                          && (!stat.init || stat.init.TYPE == prev.TYPE)) {
                     CHANGED = true;
-                    a.pop();
                     if (stat.init) {
                         stat.init.definitions = prev.definitions.concat(stat.init.definitions);
                     } else {
                         stat.init = prev;
                     }
-                    a.push(stat);
+                    statements[j] = stat;
-                    prev = stat;
                 }
                 else {
-                    prev = stat;
+                    statements[++j] = stat;
-                    a.push(stat);
                 }
-                return a;
-            }, []);
-        };
-
-    };
-
-    function extract_functions_from_statement_array(statements) {
-        var funs = [];
-        for (var i = statements.length - 1; i >= 0; --i) {
-            var stat = statements[i];
-            if (stat instanceof AST_Defun) {
-                statements.splice(i, 1);
-                funs.unshift(stat);
             }
-        }
+            statements.length = j + 1;
-        return funs;
+        };
     }
 
     function extract_declarations_from_unreachable_code(compressor, stat, target) {
@@ -1297,6 +1346,7 @@ merge(Compressor.prototype, {
         def(AST_SymbolRef, function(pure_getters) {
             if (this.is_undefined) return true;
             if (!is_strict(pure_getters)) return false;
+            if (this.is_immutable()) return false;
             var fixed = this.fixed_value();
             return !fixed || fixed._throw_on_access(pure_getters);
         });
@@ -1989,12 +2039,12 @@ merge(Compressor.prototype, {
     });
 
     OPT(AST_Block, function(self, compressor){
-        self.body = tighten_body(self.body, compressor);
+        tighten_body(self.body, compressor);
         return self;
     });
 
     OPT(AST_BlockStatement, function(self, compressor){
-        self.body = tighten_body(self.body, compressor);
+        tighten_body(self.body, compressor);
         switch (self.body.length) {
           case 1: return self.body[0];
           case 0: return make_node(AST_EmptyStatement, self);
@@ -2901,7 +2951,7 @@ merge(Compressor.prototype, {
     });
 
     OPT(AST_Try, function(self, compressor){
-        self.body = tighten_body(self.body, compressor);
+        tighten_body(self.body, compressor);
         if (self.bcatch && self.bfinally && all(self.bfinally.body, is_empty)) self.bfinally = null;
         if (all(self.body, is_empty)) {
             var body = [];
@@ -2944,18 +2994,18 @@ merge(Compressor.prototype, {
 
     OPT(AST_Call, function(self, compressor){
         var exp = self.expression;
-        if (compressor.option("reduce_vars") && exp instanceof AST_SymbolRef) {
+        var fn = exp;
-            var fixed = exp.fixed_value();
-            if (fixed instanceof AST_Function) exp = fixed;
-        }
         if (compressor.option("unused")
-            && exp instanceof AST_Function
+            && (fn instanceof AST_Function
-            && !exp.uses_arguments
+                || compressor.option("reduce_vars")
-            && !exp.uses_eval) {
+                    && fn instanceof AST_SymbolRef
+                    && (fn = fn.fixed_value()) instanceof AST_Function)
+            && !fn.uses_arguments
+            && !fn.uses_eval) {
             var pos = 0, last = 0;
             for (var i = 0, len = self.args.length; i < len; i++) {
-                var trim = i >= exp.argnames.length;
+                var trim = i >= fn.argnames.length;
-                if (trim || exp.argnames[i].__unused) {
+                if (trim || fn.argnames[i].__unused) {
                     var node = self.args[i].drop_side_effect_free(compressor);
                     if (node) {
                         self.args[pos++] = node;
@@ -3115,7 +3165,7 @@ merge(Compressor.prototype, {
                 //   https://github.com/mishoo/UglifyJS2/issues/203
                 // if the code argument is a constant, then we can minify it.
                 try {
-                    var code = "NaN(function(" + self.args.slice(0, -1).map(function(arg) {
+                    var code = "n(function(" + self.args.slice(0, -1).map(function(arg) {
                         return arg.value;
                     }).join(",") + "){" + self.args[self.args.length - 1].value + "})";
                     var ast = parse(code);
@@ -3124,7 +3174,9 @@ merge(Compressor.prototype, {
                     var comp = new Compressor(compressor.options);
                     ast = ast.transform(comp);
                     ast.figure_out_scope(mangle);
-                    ast.mangle_names();
+                    base54.reset();
+                    ast.compute_char_frequency(mangle);
+                    ast.mangle_names(mangle);
                     var fun;
                     ast.walk(new TreeWalker(function(node) {
                         if (fun) return true;
@@ -3133,18 +3185,18 @@ merge(Compressor.prototype, {
                             return true;
                         }
                     }));
-                    var args = fun.argnames.map(function(arg, i) {
-                        return make_node(AST_String, self.args[i], {
-                            value: arg.print_to_string()
-                        });
-                    });
                     var code = OutputStream();
                     AST_BlockStatement.prototype._codegen.call(fun, fun, code);
-                    code = code.toString().replace(/^\{|\}$/g, "");
+                    self.args = [
-                    args.push(make_node(AST_String, self.args[self.args.length - 1], {
+                        make_node(AST_String, self, {
-                        value: code
+                            value: fun.argnames.map(function(arg) {
-                    }));
+                                return arg.print_to_string();
-                    self.args = args;
+                            }).join(",")
+                        }),
+                        make_node(AST_String, self.args[self.args.length - 1], {
+                            value: code.get().replace(/^\{|\}$/g, "")
+                        })
+                    ];
                     return self;
                 } catch (ex) {
                     if (ex instanceof JS_Parse_Error) {
@@ -3156,79 +3208,58 @@ merge(Compressor.prototype, {
                 }
             }
         }
-        if (exp instanceof AST_Function) {
+        var stat = fn instanceof AST_Function && fn.body[0];
-            var stat = exp.body[0];
+        if (compressor.option("inline") && stat instanceof AST_Return) {
-            if (compressor.option("inline") && stat instanceof AST_Return) {
+            var value = stat.value;
-                var value = stat && stat.value;
+            if (!value || value.is_constant_expression()) {
-                if (!value || value.is_constant_expression()) {
+                var args = self.args.concat(value || make_node(AST_Undefined, self));
-                    var args = self.args.concat(value || make_node(AST_Undefined, self));
+                return make_sequence(self, args).optimize(compressor);
-                    return make_sequence(self, args).transform(compressor);
-                }
             }
+        }
+        if (exp instanceof AST_Function) {
             if (compressor.option("inline")
                 && !exp.name
-                && exp.body.length == 1
                 && !exp.uses_arguments
                 && !exp.uses_eval
+                && exp.body.length == 1
+                && all(exp.argnames, function(arg) {
+                    return arg.__unused;
+                })
                 && !self.has_pure_annotation(compressor)) {
                 var value;
                 if (stat instanceof AST_Return) {
-                    value = stat.value.clone(true);
+                    value = stat.value;
                 } else if (stat instanceof AST_SimpleStatement) {
                     value = make_node(AST_UnaryPrefix, stat, {
                         operator: "void",
-                        expression: stat.body.clone(true)
+                        expression: stat.body
                     });
                 }
                 if (value) {
-                    var fn = exp.clone();
+                    var tw = new TreeWalker(function(node) {
-                    fn.argnames = [];
+                        if (!value) return true;
-                    fn.body = [];
+                        if (node instanceof AST_SymbolRef) {
-                    if (exp.argnames.length > 0) {
+                            var ref = node.scope.find_variable(node);
-                        fn.body.push(make_node(AST_Var, self, {
+                            if (ref && ref.scope.parent_scope === fn.parent_scope) {
-                            definitions: exp.argnames.map(function(sym, i) {
+                                value = null;
-                                return make_node(AST_VarDef, sym, {
-                                    name: sym,
-                                    value: self.args[i] || make_node(AST_Undefined, self)
-                                });
-                            })
-                        }));
-                    }
-                    if (self.args.length > exp.argnames.length) {
-                        fn.body.push(make_node(AST_SimpleStatement, self, {
-                            body: make_sequence(self, self.args.slice(exp.argnames.length))
-                        }));
-                    }
-                    fn.body.push(make_node(AST_Return, self, {
-                        value: value
-                    }));
-                    var body = fn.transform(compressor).body;
-                    if (body.length == 0) return make_node(AST_Undefined, self);
-                    if (body.length == 1 && body[0] instanceof AST_Return) {
-                        value = body[0].value;
-                        if (!value) return make_node(AST_Undefined, self);
-                        value.walk(new TreeWalker(function(node) {
-                            if (value === self) return true;
-                            if (node instanceof AST_SymbolRef && matches(node.scope.find_variable(node))
-                                || node instanceof AST_This && matches(node)) {
-                                value = self;
                                 return true;
                             }
-
+                        }
-                            function matches(ref) {
+                        if (node instanceof AST_This && !tw.find_parent(AST_Scope)) {
-                                return ref && ref.scope.parent_scope === fn.parent_scope;
+                            value = null;
-                            }
+                            return true;
-                        }));
+                        }
-                        if (value !== self) value = best_of(compressor, value, self);
+                    });
-                    } else {
+                    value.walk(tw);
-                        value = self;
+                }
-                    }
+                if (value) {
-                    if (value !== self) return value;
+                    var args = self.args.concat(value);
+                    return make_sequence(self, args).optimize(compressor);
                 }
             }
             if (compressor.option("side_effects") && all(exp.body, is_empty)) {
                 var args = self.args.concat(make_node(AST_Undefined, self));
-                return make_sequence(self, args).transform(compressor);
+                return make_sequence(self, args).optimize(compressor);
             }
         }
         if (compressor.option("drop_console")) {
@@ -3357,9 +3388,12 @@ merge(Compressor.prototype, {
                             field = "left";
                         }
                     } else if (cdr instanceof AST_Call
+                            && !(left instanceof AST_PropAccess && cdr.expression.equivalent_to(left))
                         || cdr instanceof AST_PropAccess
                         || cdr instanceof AST_Unary && !unary_side_effects(cdr.operator)) {
                         field = "expression";
+                    } else if (cdr instanceof AST_Conditional) {
+                        field = "condition";
                     } else {
                         expressions[++i] = expressions[j];
                         break;
@@ -3890,7 +3924,7 @@ merge(Compressor.prototype, {
             var d = self.definition();
             var fixed = self.fixed_value();
             if (fixed instanceof AST_Defun) {
-                d.fixed = fixed = make_node(AST_Function, fixed, fixed).clone(true);
+                d.fixed = fixed = make_node(AST_Function, fixed, fixed);
             }
             if (compressor.option("unused")
                 && fixed instanceof AST_Function
@@ -3898,7 +3932,7 @@ merge(Compressor.prototype, {
                 && !(d.scope.uses_arguments && d.orig[0] instanceof AST_SymbolFunarg)
                 && !d.scope.uses_eval
                 && compressor.find_parent(AST_Scope) === fixed.parent_scope) {
-                return fixed;
+                return fixed.clone(true);
             }
             if (compressor.option("evaluate") && fixed) {
                 if (d.should_replace === undefined) {
@@ -3921,7 +3955,7 @@ merge(Compressor.prototype, {
                         }
                         var name_length = d.name.length;
                         var overhead = 0;
-                        if (compressor.option("unused") && (!d.global || compressor.toplevel(d))) {
+                        if (compressor.option("unused") && !compressor.exposed(d)) {
                             overhead = (name_length + 2 + value_length) / d.references.length;
                         }
                         d.should_replace = value_length <= name_length + overhead ? fn : false;

lib/minify.js

@@ -27,6 +27,23 @@ function set_shorthand(name, options, keys) {
     }
 }
 
+function init_cache(cache) {
+    if (!cache) return;
+    if (!("cname" in cache)) cache.cname = -1;
+    if (!("props" in cache)) {
+        cache.props = new Dictionary();
+    } else if (!(cache.props instanceof Dictionary)) {
+        cache.props = Dictionary.fromObject(cache.props);
+    }
+}
+
+function to_json(cache) {
+    return {
+        cname: cache.cname,
+        props: cache.props.toObject()
+    };
+}
+
 function minify(files, options) {
     var warn_function = AST_Node.warn_function;
     try {
@@ -35,6 +52,7 @@ function minify(files, options) {
             ie8: false,
             keep_fnames: false,
             mangle: {},
+            nameCache: null,
             output: {},
             parse: {},
             sourceMap: false,
@@ -52,7 +70,7 @@ function minify(files, options) {
         set_shorthand("warnings", options, [ "compress" ]);
         if (options.mangle) {
             options.mangle = defaults(options.mangle, {
-                cache: null,
+                cache: options.nameCache && (options.nameCache.vars || {}),
                 eval: false,
                 ie8: false,
                 keep_fnames: false,
@@ -60,6 +78,16 @@ function minify(files, options) {
                 reserved: [],
                 toplevel: false,
             }, true);
+            if (options.nameCache && options.mangle.properties) {
+                if (typeof options.mangle.properties != "object") {
+                    options.mangle.properties = {};
+                }
+                if (!("cache" in options.mangle.properties)) {
+                    options.mangle.properties.cache = options.nameCache.props || {};
+                }
+            }
+            init_cache(options.mangle.cache);
+            init_cache(options.mangle.properties.cache);
         }
         if (options.sourceMap) {
             options.sourceMap = defaults(options.sourceMap, {
@@ -153,6 +181,12 @@ function minify(files, options) {
                 }
             }
         }
+        if (options.nameCache && options.mangle) {
+            if (options.mangle.cache) options.nameCache.vars = to_json(options.mangle.cache);
+            if (options.mangle.properties && options.mangle.properties.cache) {
+                options.nameCache.props = to_json(options.mangle.properties.cache);
+            }
+        }
         if (timings) {
             timings.end = Date.now();
             result.timings = {

lib/output.js

@@ -501,6 +501,7 @@ function OutputStream(options) {
             use_asm = prev_use_asm;
         }
     });
+    AST_Node.DEFMETHOD("_print", AST_Node.prototype.print);
 
     AST_Node.DEFMETHOD("print_to_string", function(options){
         var s = OutputStream(options);

lib/parse.js

@@ -1010,8 +1010,12 @@ function parse($TEXT, options) {
                 ? (next(), var_(true))
                 : expression(true, true);
             if (is("operator", "in")) {
-                if (init instanceof AST_Var && init.definitions.length > 1)
+                if (init instanceof AST_Var) {
-                    croak("Only one variable declaration allowed in for..in loop");
+                    if (init.definitions.length > 1)
+                        croak("Only one variable declaration allowed in for..in loop", init.start.line, init.start.col, init.start.pos);
+                } else if (!is_assignable(init)) {
+                    croak("Invalid left-hand side in for..in loop", init.start.line, init.start.col, init.start.pos);
+                }
                 next();
                 return for_in(init);
             }

lib/scope.js

@@ -79,7 +79,7 @@ SymbolDef.prototype = {
             if (options.ie8 && sym instanceof AST_SymbolLambda)
                 s = s.parent_scope;
             var def;
-            if (this.defun && (def = this.defun.variables.get(this.name))) {
+            if (def = this.redefined()) {
                 this.mangled_name = def.mangled_name || def.name;
             } else
                 this.mangled_name = s.next_mangled(options, this);
@@ -87,6 +87,9 @@ SymbolDef.prototype = {
                 cache.set(this.name, this.mangled_name);
             }
         }
+    },
+    redefined: function() {
+        return this.defun && this.defun.variables.get(this.name);
     }
 };
 
@@ -206,6 +209,16 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             node.reference(options);
             return true;
         }
+        // ensure mangling works if catch reuses a scope variable
+        var def;
+        if (node instanceof AST_SymbolCatch && (def = node.definition().redefined())) {
+            var s = node.scope;
+            while (s) {
+                push_uniq(s.enclosed, def);
+                if (s === def.scope) break;
+                s = s.parent_scope;
+            }
+        }
     });
     self.walk(tw);
 
@@ -348,7 +361,8 @@ AST_Function.DEFMETHOD("next_mangled", function(options, def){
 });
 
 AST_Symbol.DEFMETHOD("unmangleable", function(options){
-    return this.definition().unmangleable(options);
+    var def = this.definition();
+    return !def || def.unmangleable(options);
 });
 
 // labels are always mangleable
@@ -447,103 +461,69 @@ AST_Toplevel.DEFMETHOD("mangle_names", function(options){
 
 AST_Toplevel.DEFMETHOD("compute_char_frequency", function(options){
     options = this._default_mangler_options(options);
-    var tw = new TreeWalker(function(node){
+    try {
-        if (node instanceof AST_Constant)
+        AST_Node.prototype.print = function(stream, force_parens) {
-            base54.consider(node.print_to_string());
+            this._print(stream, force_parens);
-        else if (node instanceof AST_Return)
+            if (this instanceof AST_Symbol && !this.unmangleable(options)) {
-            base54.consider("return");
+                base54.consider(this.name, -1);
-        else if (node instanceof AST_Throw)
+            } else if (options.properties) {
-            base54.consider("throw");
+                if (this instanceof AST_Dot) {
-        else if (node instanceof AST_Continue)
+                    base54.consider(this.property, -1);
-            base54.consider("continue");
+                } else if (this instanceof AST_Sub) {
-        else if (node instanceof AST_Break)
+                    skip_string(this.property);
-            base54.consider("break");
+                }
-        else if (node instanceof AST_Debugger)
+            }
-            base54.consider("debugger");
+        };
-        else if (node instanceof AST_Directive)
+        base54.consider(this.print_to_string(), 1);
-            base54.consider(node.value);
+    } finally {
-        else if (node instanceof AST_While)
+        AST_Node.prototype.print = AST_Node.prototype._print;
-            base54.consider("while");
+    }
-        else if (node instanceof AST_Do)
-            base54.consider("do while");
-        else if (node instanceof AST_If) {
-            base54.consider("if");
-            if (node.alternative) base54.consider("else");
-        }
-        else if (node instanceof AST_Var)
-            base54.consider("var");
-        else if (node instanceof AST_Lambda)
-            base54.consider("function");
-        else if (node instanceof AST_For)
-            base54.consider("for");
-        else if (node instanceof AST_ForIn)
-            base54.consider("for in");
-        else if (node instanceof AST_Switch)
-            base54.consider("switch");
-        else if (node instanceof AST_Case)
-            base54.consider("case");
-        else if (node instanceof AST_Default)
-            base54.consider("default");
-        else if (node instanceof AST_With)
-            base54.consider("with");
-        else if (node instanceof AST_ObjectSetter)
-            base54.consider("set" + node.key);
-        else if (node instanceof AST_ObjectGetter)
-            base54.consider("get" + node.key);
-        else if (node instanceof AST_ObjectKeyVal)
-            base54.consider(node.key);
-        else if (node instanceof AST_New)
-            base54.consider("new");
-        else if (node instanceof AST_This)
-            base54.consider("this");
-        else if (node instanceof AST_Try)
-            base54.consider("try");
-        else if (node instanceof AST_Catch)
-            base54.consider("catch");
-        else if (node instanceof AST_Finally)
-            base54.consider("finally");
-        else if (node instanceof AST_Symbol && node.unmangleable(options))
-            base54.consider(node.name);
-        else if (node instanceof AST_Unary || node instanceof AST_Binary)
-            base54.consider(node.operator);
-        else if (node instanceof AST_Dot)
-            base54.consider(node.property);
-    });
-    this.walk(tw);
     base54.sort();
+
+    function skip_string(node) {
+        if (node instanceof AST_String) {
+            base54.consider(node.value, -1);
+        } else if (node instanceof AST_Conditional) {
+            skip_string(node.consequent);
+            skip_string(node.alternative);
+        } else if (node instanceof AST_Sequence) {
+            skip_string(node.expressions[node.expressions.length - 1]);
+        }
+    }
 });
 
 var base54 = (function() {
-    var string = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_0123456789";
+    var leading = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_".split("");
+    var digits = "0123456789".split("");
     var chars, frequency;
     function reset() {
         frequency = Object.create(null);
-        chars = string.split("").map(function(ch){ return ch.charCodeAt(0) });
+        leading.forEach(function(ch) {
-        chars.forEach(function(ch){ frequency[ch] = 0 });
+            frequency[ch] = 0;
+        });
+        digits.forEach(function(ch) {
+            frequency[ch] = 0;
+        });
     }
-    base54.consider = function(str){
+    base54.consider = function(str, delta) {
         for (var i = str.length; --i >= 0;) {
-            var code = str.charCodeAt(i);
+            frequency[str[i]] += delta;
-            if (code in frequency) ++frequency[code];
         }
     };
+    function compare(a, b) {
+        return frequency[b] - frequency[a];
+    }
     base54.sort = function() {
-        chars = mergeSort(chars, function(a, b){
+        chars = mergeSort(leading, compare).concat(mergeSort(digits, compare));
-            if (is_digit(a) && !is_digit(b)) return 1;
-            if (is_digit(b) && !is_digit(a)) return -1;
-            return frequency[b] - frequency[a];
-        });
     };
     base54.reset = reset;
     reset();
-    base54.get = function(){ return chars };
-    base54.freq = function(){ return frequency };
     function base54(num) {
         var ret = "", base = 54;
         num++;
         do {
             num--;
-            ret += String.fromCharCode(chars[num % base]);
+            ret += chars[num % base];
             num = Math.floor(num / base);
             base = 64;
         } while (num > 0);

package.json

@@ -4,7 +4,7 @@
   "homepage": "http://lisperator.net/uglifyjs",
   "author": "Mihai Bazon <mihai.bazon@gmail.com> (http://lisperator.net/)",
   "license": "BSD-2-Clause",
-  "version": "3.0.17",
+  "version": "3.0.23",
   "engines": {
     "node": ">=0.8.0"
   },

test/compress/collapse_vars.js

@@ -1978,10 +1978,10 @@ chained_3: {
     }
     expect: {
         console.log(function(a, b) {
-            var c = a, c = b;
+            var c = 1, c = b;
             b++;
             return c;
-        }(1, 2));
+        }(0, 2));
     }
     expect_stdout: "2"
 }
@@ -2186,3 +2186,73 @@ compound_assignment: {
     }
     expect_stdout: "4"
 }
+
+issue_2187_1: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        !function(foo) {
+            foo();
+            var a = 2;
+            console.log(a);
+        }(function() {
+            console.log(a);
+        });
+    }
+    expect: {
+        var a = 1;
+        !function(foo) {
+            foo();
+            var a = 2;
+            console.log(a);
+        }(function() {
+            console.log(a);
+        });
+    }
+    expect_stdout: [
+        "1",
+        "2",
+    ]
+}
+
+issue_2187_2: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        var b = 1;
+        console.log(function(a) {
+            return a && ++b;
+        }(b--));
+    }
+    expect: {
+        var b = 1;
+        console.log(function(a) {
+            return b-- && ++b;
+        }());
+    }
+    expect_stdout: "1"
+}
+
+issue_2187_3: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        unused: true,
+    }
+    input: {
+        var b = 1;
+        console.log(function(a) {
+            return a && ++b;
+        }(b--));
+    }
+    expect: {
+        var b = 1;
+        console.log(b-- && ++b);
+    }
+    expect_stdout: "1"
+}

test/compress/drop-unused.js

@@ -1108,3 +1108,48 @@ var_catch_toplevel: {
         }();
     }
 }
+
+issue_2105: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        passes: 3,
+        reduce_vars: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        !function(factory) {
+            factory();
+        }( function() {
+            return function(fn) {
+                fn()().prop();
+            }( function() {
+                function bar() {
+                    var quux = function() {
+                        console.log("PASS");
+                    }, foo = function() {
+                        console.log;
+                        quux();
+                    };
+                    return { prop: foo };
+                }
+                return bar;
+            } );
+        });
+    }
+    expect: {
+        (function() {
+            var quux = function() {
+                console.log("PASS");
+            };
+            return {
+                prop: function() {
+                    console.log;
+                    quux();
+                }
+            };
+        })().prop();
+    }
+    expect_stdout: "PASS"
+}

test/compress/functions.js

@@ -265,7 +265,7 @@ issue_203: {
     }
     expect: {
         var m = {};
-        var fn = Function("a", "b", "b.exports=42");
+        var fn = Function("n,o", "o.exports=42");
         fn(null, m, m.exports);
         console.log(m.exports);
     }
@@ -414,3 +414,97 @@ inner_ref: {
     }
     expect_stdout: "1 undefined"
 }
+
+issue_2107: {
+    options = {
+        cascade: true,
+        collapse_vars: true,
+        inline: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        !function() {
+            c++;
+        }(c++ + new function() {
+            this.a = 0;
+            var a = (c = c + 1) + (c = 1 + c);
+            return c++ + a;
+        }());
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        c++, new function() {
+            this.a = 0, c = 1 + (c += 1), c++;
+        }(), c++, console.log(c);
+    }
+    expect_stdout: "5"
+}
+
+issue_2114_1: {
+    options = {
+        collapse_vars: true,
+        if_return: true,
+        inline: true,
+        keep_fargs: false,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        !function(a) {
+            a = 0;
+        }([ {
+            0: c = c + 1,
+            length: c = 1 + c
+        }, typeof void function a() {
+            var b = function f1(a) {
+            }(b && (b.b += (c = c + 1, 0)));
+        }() ]);
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        c = 1 + (c += 1), function() {
+            var b = void (b && (b.b += (c += 1, 0)));
+        }();
+        console.log(c);
+    }
+    expect_stdout: "2"
+}
+
+issue_2114_2: {
+    options = {
+        collapse_vars: true,
+        if_return: true,
+        inline: true,
+        keep_fargs: false,
+        passes: 2,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        var c = 0;
+        !function(a) {
+            a = 0;
+        }([ {
+            0: c = c + 1,
+            length: c = 1 + c
+        }, typeof void function a() {
+            var b = function f1(a) {
+            }(b && (b.b += (c = c + 1, 0)));
+        }() ]);
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        c = 1 + (c += 1), function() {
+            var b = void (b && (b.b += (c += 1, 0)));
+        }();
+        console.log(c);
+    }
+    expect_stdout: "2"
+}

test/compress/global_defs.js

@@ -174,3 +174,24 @@ issue_1986: {
         console.log(42);
     }
 }
+
+issue_2167: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        global_defs: {
+            "@isDevMode": "function(){}",
+        },
+        side_effects: true,
+    }
+    input: {
+        if (isDevMode()) {
+            greetOverlord();
+        }
+        doWork();
+    }
+    expect: {
+        doWork();
+    }
+}

test/compress/issue-1321.js

@@ -10,9 +10,9 @@ issue_1321_no_debug: {
     }
     expect: {
         var x = {};
-        x.b = 1;
+        x.o = 1;
-        x["a"] = 2 * x.b;
+        x["a"] = 2 * x.o;
-        console.log(x.b, x["a"]);
+        console.log(x.o, x["a"]);
     }
     expect_stdout: true
 }
@@ -30,9 +30,9 @@ issue_1321_debug: {
     }
     expect: {
         var x = {};
-        x.a = 1;
+        x.o = 1;
-        x["_$foo$_"] = 2 * x.a;
+        x["_$foo$_"] = 2 * x.o;
-        console.log(x.a, x["_$foo$_"]);
+        console.log(x.o, x["_$foo$_"]);
     }
     expect_stdout: true
 }
@@ -49,9 +49,9 @@ issue_1321_with_quoted: {
     }
     expect: {
         var x = {};
-        x.a = 1;
+        x.o = 1;
-        x["b"] = 2 * x.a;
+        x["x"] = 2 * x.o;
-        console.log(x.a, x["b"]);
+        console.log(x.o, x["x"]);
     }
     expect_stdout: true
 }

test/compress/issue-1770.js

@@ -82,7 +82,7 @@ numeric_literal: {
         '    42: 2,',
         '    "42": 3,',
         '    37: 4,',
-        '    a: 5,',
+        '    o: 5,',
         '    1e42: 6,',
         '    b: 7,',
         '    "1e+42": 8',
@@ -92,7 +92,7 @@ numeric_literal: {
         '',
         'console.log(obj[42], obj["42"]);',
         '',
-        'console.log(obj[37], obj["a"], obj[37], obj["37"]);',
+        'console.log(obj[37], obj["o"], obj[37], obj["37"]);',
         '',
         'console.log(obj[1e42], obj["b"], obj["1e+42"]);',
     ]
@@ -173,32 +173,32 @@ identifier: {
     }
     expect: {
         var obj = {
-            a: 1,
+            e: 1,
-            b: 2,
+            t: 2,
-            c: 3,
+            n: 3,
-            d: 4,
+            a: 4,
-            e: 5,
+            i: 5,
-            f: 6,
+            o: 6,
-            g: 7,
+            r: 7,
-            h: 8,
+            l: 8,
-            i: 9,
+            s: 9,
-            j: 10,
+            c: 10,
-            k: 11,
+            f: 11,
-            l: 12,
+            u: 12,
-            m: 13,
+            d: 13,
-            n: 14,
+            h: 14,
-            o: 15,
+            p: 15,
-            p: 16,
+            b: 16,
-            q: 17,
+            v: 17,
-            r: 18,
+            w: 18,
-            s: 19,
+            y: 19,
-            t: 20,
+            g: 20,
-            u: 21,
+            m: 21,
-            v: 22,
+            k: 22,
-            w: 23,
+            x: 23,
-            x: 24,
+            j: 24,
-            y: 25,
+            z: 25,
-            z: 26,
+            q: 26,
             A: 27,
             B: 28,
             C: 29,
@@ -229,11 +229,11 @@ identifier: {
             Z: 54,
             $: 55,
             _: 56,
-            aa: 57,
+            ee: 57,
-            ba: 58,
+            te: 58,
-            ca: 59,
+            ne: 59,
-            da: 60,
+            ae: 60,
-            ea: 61,
+            ie: 61,
         };
     }
 }

test/compress/issue-281.js

@@ -419,7 +419,7 @@ wrap_iife_in_return_call: {
     expect_exact: '(void console.log("test"))();'
 }
 
-pure_annotation: {
+pure_annotation_1: {
     options = {
         inline: true,
         side_effects: true,
@@ -432,6 +432,20 @@ pure_annotation: {
     expect_exact: ""
 }
 
+pure_annotation_2: {
+    options = {
+        collapse_vars: true,
+        inline: true,
+        side_effects: true,
+    }
+    input: {
+        /*@__PURE__*/(function(n) {
+            console.log("hello", n);
+        }(42));
+    }
+    expect_exact: ""
+}
+
 drop_fargs: {
     options = {
         cascade: true,
@@ -449,9 +463,7 @@ drop_fargs: {
     }
     expect: {
         var a = 1;
-        !function() {
+        ++a && a.var, a++;
-            a++;
-        }(++a && a.var);
         console.log(a);
     }
     expect_stdout: "3"
@@ -474,9 +486,7 @@ keep_fargs: {
     }
     expect: {
         var a = 1;
-        !function(a_1) {
+        ++a && a.var, a++;
-            a++;
-        }(++a && a.var);
         console.log(a);
     }
     expect_stdout: "3"

test/compress/issue-747.js

@@ -1,37 +1,41 @@
 dont_reuse_prop: {
     mangle_props = {
         regex: /asd/
-    };
+    }
-
     input: {
+        "aaaaaaaaaabbbbb";
         var obj = {};
         obj.a = 123;
         obj.asd = 256;
         console.log(obj.a);
     }
     expect: {
+        "aaaaaaaaaabbbbb";
         var obj = {};
         obj.a = 123;
         obj.b = 256;
         console.log(obj.a);
     }
+    expect_stdout: "123"
 }
 
 unmangleable_props_should_always_be_reserved: {
     mangle_props = {
         regex: /asd/
-    };
+    }
-
     input: {
+        "aaaaaaaaaabbbbb";
         var obj = {};
         obj.asd = 256;
         obj.a = 123;
         console.log(obj.a);
     }
     expect: {
+        "aaaaaaaaaabbbbb";
         var obj = {};
         obj.b = 256;
         obj.a = 123;
         console.log(obj.a);
     }
-}
+    expect_stdout: "123"
+}

test/compress/properties.js

@@ -135,11 +135,11 @@ mangle_properties: {
         a['run']({color: "blue", foo: "baz"});
     }
     expect: {
-        a["a"] = "bar";
+        a["o"] = "bar";
-        a.b = "red";
+        a.a = "red";
-        x = {c: 10};
+        x = {r: 10};
-        a.d(x.c, a.a);
+        a.b(x.r, a.o);
-        a['d']({b: "blue", a: "baz"});
+        a['b']({a: "blue", o: "baz"});
     }
 }
 
@@ -177,16 +177,16 @@ mangle_unquoted_properties: {
         function f1() {
             a["foo"] = "bar";
             a.color = "red";
-            a.b = 2;
+            a.o = 2;
-            x = {"bar": 10, c: 7};
+            x = {"bar": 10, f: 7};
-            a.c = 9;
+            a.f = 9;
         }
         function f2() {
             a.foo = "bar";
             a['color'] = "red";
-            x = {bar: 10, c: 7};
+            x = {bar: 10, f: 7};
-            a.c = 9;
+            a.f = 9;
-            a.b = 3;
+            a.o = 3;
         }
     }
 }

test/compress/pure_getters.js

@@ -178,3 +178,210 @@ impure_getter_2: {
     }
     expect: {}
 }
+
+issue_2110_1: {
+    options = {
+        cascade: true,
+        pure_getters: "strict",
+        sequences: true,
+        side_effects: true,
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function f() {}
+            function g() {
+                return this;
+            }
+            f.g = g;
+            return f.g();
+        }
+        console.log(typeof f());
+    }
+    expect: {
+        function f() {
+            function f() {}
+            return f.g = function() {
+                return this;
+            }, f.g();
+        }
+        console.log(typeof f());
+    }
+    expect_stdout: "function"
+}
+
+issue_2110_2: {
+    options = {
+        collapse_vars: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            function f() {}
+            function g() {
+                return this;
+            }
+            f.g = g;
+            return f.g();
+        }
+        console.log(typeof f());
+    }
+    expect: {
+        function f() {
+            function f() {}
+            f.g = function() {
+                return this;
+            };
+            return f.g();
+        }
+        console.log(typeof f());
+    }
+    expect_stdout: "function"
+}
+
+set_immutable_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        1..foo += "";
+        if (1..foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+set_immutable_2: {
+    options = {
+        cascade: true,
+        conditionals: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        var a = 1;
+        a.foo += "", a.foo ? console.log("FAIL") : console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+set_immutable_3: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        "use strict";
+        1..foo += "";
+        if (1..foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect_stdout: true
+}
+
+set_immutable_4: {
+    options = {
+        cascade: true,
+        conditionals: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+    }
+    input: {
+        "use strict";
+        var a = 1;
+        a.foo += "";
+        if (a.foo) console.log("FAIL");
+        else console.log("PASS");
+    }
+    expect: {
+        "use strict";
+        var a = 1;
+        a.foo += "", a.foo ? console.log("FAIL") : console.log("PASS");
+    }
+    expect_stdout: true
+}
+
+set_mutable_1: {
+    options = {
+        collapse_vars: true,
+        evaluate: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        !function a() {
+            a.foo += "";
+            if (a.foo) console.log("PASS");
+            else console.log("FAIL");
+        }();
+    }
+    expect: {
+        !function a() {
+            if (a.foo += "") console.log("PASS");
+            else console.log("FAIL");
+        }();
+    }
+    expect_stdout: "PASS"
+}
+
+set_mutable_2: {
+    options = {
+        cascade: true,
+        conditionals: true,
+        pure_getters: "strict",
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        !function a() {
+            a.foo += "";
+            if (a.foo) console.log("PASS");
+            else console.log("FAIL");
+        }();
+    }
+    expect: {
+        !function a() {
+            (a.foo += "") ? console.log("PASS") : console.log("FAIL");
+        }();
+    }
+    expect_stdout: "PASS"
+}

test/compress/reduce_vars.js

@@ -2575,3 +2575,28 @@ accessor: {
     }
     expect_stdout: "1 1"
 }
+
+for_in_prop: {
+    options = {
+        reduce_vars: true,
+    }
+    input: {
+        var a = {
+            foo: function() {
+                for (this.b in [1, 2]);
+            }
+        };
+        a.foo();
+        console.log(a.b);
+    }
+    expect: {
+        var a = {
+            foo: function() {
+                for (this.b in [1, 2]);
+            }
+        };
+        a.foo();
+        console.log(a.b);
+    }
+    expect_stdout: "1"
+}

test/compress/screw-ie8.js

@@ -255,3 +255,73 @@ issue_1586_2: {
     }
     expect_exact: "function f(){try{x()}catch(c){console.log(c.message)}}"
 }
+
+issue_2120_1: {
+    mangle = {
+        ie8: false,
+    }
+    input: {
+        "aaaaaaaa";
+        var a = 1, b = "FAIL";
+        try {
+            throw 1;
+        } catch (c) {
+            try {
+                throw 0;
+            } catch (a) {
+                if (c) b = "PASS";
+            }
+        }
+        console.log(b);
+    }
+    expect: {
+        "aaaaaaaa";
+        var a = 1, b = "FAIL";
+        try {
+            throw 1;
+        } catch (t) {
+            try {
+                throw 0;
+            } catch (a) {
+                if (t) b = "PASS";
+            }
+        }
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_2120_2: {
+    mangle = {
+        ie8: true,
+    }
+    input: {
+        "aaaaaaaa";
+        var a = 1, b = "FAIL";
+        try {
+            throw 1;
+        } catch (c) {
+            try {
+                throw 0;
+            } catch (a) {
+                if (c) b = "PASS";
+            }
+        }
+        console.log(b);
+    }
+    expect: {
+        "aaaaaaaa";
+        var a = 1, b = "FAIL";
+        try {
+            throw 1;
+        } catch (c) {
+            try {
+                throw 0;
+            } catch (a) {
+                if (c) b = "PASS";
+            }
+        }
+        console.log(b);
+    }
+    expect_stdout: "PASS"
+}

test/input/invalid/for-in_1.js

@@ -0,0 +1,4 @@
+var a, b = [1, 2];
+for (1, 2, a in b) {
+    console.log(a, b[a]);
+}

test/input/invalid/for-in_2.js

@@ -0,0 +1,4 @@
+var c = [1, 2];
+for (var a, b in c) {
+    console.log(a, c[a]);
+}

test/mocha/cli.js

@@ -518,6 +518,36 @@ describe("bin/uglifyjs", function () {
             done();
         });
     });
+    it("Should throw syntax error (for-in init)", function(done) {
+        var command = uglifyjscmd + ' test/input/invalid/for-in_1.js';
+
+        exec(command, function (err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/for-in_1.js:2,5",
+                "for (1, 2, a in b) {",
+                "     ^",
+                "ERROR: Invalid left-hand side in for..in loop"
+            ].join("\n"));
+            done();
+        });
+    });
+    it("Should throw syntax error (for-in var)", function(done) {
+        var command = uglifyjscmd + ' test/input/invalid/for-in_2.js';
+
+        exec(command, function (err, stdout, stderr) {
+            assert.ok(err);
+            assert.strictEqual(stdout, "");
+            assert.strictEqual(stderr.split(/\n/).slice(0, 4).join("\n"), [
+                "Parse error at test/input/invalid/for-in_2.js:2,5",
+                "for (var a, b in c) {",
+                "     ^",
+                "ERROR: Only one variable declaration allowed in for..in loop"
+            ].join("\n"));
+            done();
+        });
+    });
     it("Should handle literal string as source map input", function(done) {
         var command = [
             uglifyjscmd,

test/mocha/glob.js

@@ -26,12 +26,12 @@ describe("bin/uglifyjs with input file globs", function() {
         });
     });
     it("bin/uglifyjs with multiple input file globs.", function(done) {
-        var command = uglifyjscmd + ' "test/input/issue-1242/???.es5" "test/input/issue-1242/*.js" -mc toplevel';
+        var command = uglifyjscmd + ' "test/input/issue-1242/???.es5" "test/input/issue-1242/*.js" -mc toplevel,passes=2';
 
         exec(command, function(err, stdout) {
             if (err) throw err;
 
-            assert.strictEqual(stdout, 'var print=console.log.bind(console);print("qux",9,6),print("Foo:",2*11);\n');
+            assert.strictEqual(stdout, 'var print=console.log.bind(console);print("qux",9,6),print("Foo:",22);\n');
             done();
         });
     });

test/mocha/let.js

@@ -2,29 +2,37 @@ var Uglify = require('../../');
 var assert = require("assert");
 
 describe("let", function() {
-    it("Should not produce `let` as a variable name in mangle", function(done) {
+    it("Should not produce reserved keywords as variable name in mangle", function(done) {
         this.timeout(10000);
 
         // Produce a lot of variables in a function and run it through mangle.
-        var s = '"use strict"; function foo() {';
+        var s = '"dddddeeeeelllllooooottttt"; function foo() {';
-        for (var i = 0; i < 21000; ++i) {
+        for (var i = 0; i < 18000; i++) {
             s += "var v" + i + "=0;";
         }
         s += '}';
         var result = Uglify.minify(s, {compress: false});
 
         // Verify that select keywords and reserved keywords not produced
-        assert.strictEqual(result.code.indexOf("var let="), -1);
+        [
-        assert.strictEqual(result.code.indexOf("var do="), -1);
+            "do",
-        assert.strictEqual(result.code.indexOf("var var="), -1);
+            "let",
+            "var",
+        ].forEach(function(name) {
+            assert.strictEqual(result.code.indexOf("var " + name + "="), -1);
+        });
 
         // Verify that the variable names that appeared immediately before
-        // and after the erroneously generated `let` variable name still exist
+        // and after the erroneously generated variable name still exist
         // to show the test generated enough symbols.
-        assert(result.code.indexOf("var ket=") >= 0);
+        [
-        assert(result.code.indexOf("var met=") >= 0);
+            "to", "eo",
+            "eet", "fet",
+            "rar", "oar",
+        ].forEach(function(name) {
+            assert.ok(result.code.indexOf("var " + name + "=") >= 0);
+        });
 
         done();
     });
 });
-

test/mocha/minify.js

@@ -1,6 +1,7 @@
 var Uglify = require('../../');
 var assert = require("assert");
 var readFileSync = require("fs").readFileSync;
+var run_code = require("../sandbox").run_code;
 
 function read(path) {
     return readFileSync(path, "utf8");
@@ -20,6 +21,58 @@ describe("minify", function() {
         assert.strictEqual(result.code, "alert(2);");
     });
 
+    it("Should work with mangle.cache", function() {
+        var cache = {};
+        var original = "";
+        var compressed = "";
+        [
+            "bar.es5",
+            "baz.es5",
+            "foo.es5",
+            "qux.js",
+        ].forEach(function(file) {
+            var code = read("test/input/issue-1242/" + file);
+            var result = Uglify.minify(code, {
+                mangle: {
+                    cache: cache,
+                    toplevel: true
+                }
+            });
+            if (result.error) throw result.error;
+            original += code;
+            compressed += result.code;
+        });
+        assert.strictEqual(JSON.stringify(cache).slice(0, 20), '{"cname":5,"props":{');
+        assert.strictEqual(compressed, 'function n(n){return 3*n}function r(n){return n/2}function c(o){l("Foo:",2*o)}var l=console.log.bind(console);var f=n(3),i=r(12);l("qux",f,i),c(11);');
+        assert.strictEqual(run_code(compressed), run_code(original));
+    });
+
+    it("Should work with nameCache", function() {
+        var cache = {};
+        var original = "";
+        var compressed = "";
+        [
+            "bar.es5",
+            "baz.es5",
+            "foo.es5",
+            "qux.js",
+        ].forEach(function(file) {
+            var code = read("test/input/issue-1242/" + file);
+            var result = Uglify.minify(code, {
+                mangle: {
+                    toplevel: true
+                },
+                nameCache: cache
+            });
+            if (result.error) throw result.error;
+            original += code;
+            compressed += result.code;
+        });
+        assert.strictEqual(JSON.stringify(cache).slice(0, 28), '{"vars":{"cname":5,"props":{');
+        assert.strictEqual(compressed, 'function n(n){return 3*n}function r(n){return n/2}function c(o){l("Foo:",2*o)}var l=console.log.bind(console);var f=n(3),i=r(12);l("qux",f,i),c(11);');
+        assert.strictEqual(run_code(compressed), run_code(original));
+    });
+
     describe("keep_quoted_props", function() {
         it("Should preserve quotes in object literals", function() {
             var js = 'var foo = {"x": 1, y: 2, \'z\': 3};';
@@ -212,7 +265,7 @@ describe("minify", function() {
             });
             var err = result.error;
             assert.ok(err instanceof Error);
-            assert.strictEqual(err.stack.split(/\n/)[0], "Error: Can't handle expression: debugger");
+            assert.strictEqual(err.stack.split(/\n/)[0], "SyntaxError: Unexpected token: keyword (debugger)");
         });
         it("should skip inherited properties", function() {
             var foo = Object.create({ skip: this });

test/run-tests.js

@@ -86,7 +86,6 @@ function run_compress_tests() {
         log_start_file(file);
         function test_case(test) {
             log_test(test.name);
-            U.base54.reset();
             var output_options = test.beautify || {};
             var expect;
             if (test.expect) {
@@ -101,9 +100,6 @@ function run_compress_tests() {
                 quote_style: 3,
                 keep_quoted_props: true
             });
-            if (test.mangle_props) {
-                input = U.mangle_properties(input, test.mangle_props);
-            }
             var options = U.defaults(test.options, {
                 warnings: false
             });
@@ -118,10 +114,16 @@ function run_compress_tests() {
             var cmp = new U.Compressor(options, true);
             var output = cmp.compress(input);
             output.figure_out_scope(test.mangle);
-            if (test.mangle) {
+            if (test.mangle || test.mangle_props) {
+                U.base54.reset();
                 output.compute_char_frequency(test.mangle);
+            }
+            if (test.mangle) {
                 output.mangle_names(test.mangle);
             }
+            if (test.mangle_props) {
+                output = U.mangle_properties(output, test.mangle_props);
+            }
             output = make_code(output, output_options);
             if (expect != output) {
                 log("!!! failed\n---INPUT---\n{input}\n---OUTPUT---\n{output}\n---EXPECTED---\n{expected}\n\n", {