v3.11.5

fixes #4257

bin/uglifyjs

@@ -276,7 +276,9 @@ function convert_ast(fn) {
 function run() {
     var content = options.sourceMap && options.sourceMap.content;
     if (content && content != "inline") {
-        UglifyJS.AST_Node.info("Using input source map: " + content);
+        UglifyJS.AST_Node.info("Using input source map: {content}", {
+            content : content,
+        });
         options.sourceMap.content = read_file(content, content);
     }
     try {

lib/ast.js

@@ -137,17 +137,17 @@ var AST_Node = DEFNODE("Node", "start end", {
 }, null);
 
 (AST_Node.log_function = function(fn, verbose) {
-    var printed = Object.create(null);
-    if (fn) {
-        AST_Node.info = verbose ? function(text, props) {
-            log("INFO: " + string_template(text, props));
-        } : noop;
-        AST_Node.warn = function(text, props) {
-            log("WARN: " + string_template(text, props));
-        };
-    } else {
+    if (!fn) {
         AST_Node.info = AST_Node.warn = noop;
+        return;
     }
+    var printed = Object.create(null);
+    AST_Node.info = verbose ? function(text, props) {
+        log("INFO: " + string_template(text, props));
+    } : noop;
+    AST_Node.warn = function(text, props) {
+        log("WARN: " + string_template(text, props));
+    };
 
     function log(msg) {
         if (printed[msg]) return;

lib/compress.js

@@ -192,7 +192,11 @@ merge(Compressor.prototype, {
                 node.walk(new TreeWalker(function() {
                     count++;
                 }));
-                AST_Node.info("pass " + pass + ": last_count: " + min_count + ", count: " + count);
+                AST_Node.info("pass {pass}: last_count: {min_count}, count: {count}", {
+                    pass: pass,
+                    min_count: min_count,
+                    count: count,
+                });
                 if (count < min_count) {
                     min_count = count;
                     stopping = false;
@@ -1340,11 +1344,11 @@ merge(Compressor.prototype, {
                         replaced++;
                     }
                     CHANGED = abort = true;
-                    AST_Node.info("Collapsing {name} [{file}:{line},{col}]", {
-                        name: node.print_to_string(),
+                    AST_Node.info("Collapsing {node} [{file}:{line},{col}]", {
+                        node: node,
                         file: node.start.file,
                         line: node.start.line,
-                        col: node.start.col
+                        col: node.start.col,
                     });
                     if (candidate instanceof AST_UnaryPostfix) {
                         if (lhs instanceof AST_SymbolRef) lhs.definition().fixed = false;
@@ -1552,12 +1556,17 @@ merge(Compressor.prototype, {
                 if (node instanceof AST_Defun) return funarg && lhs.name === node.name.name;
                 if (node instanceof AST_DWLoop) return true;
                 if (node instanceof AST_LoopControl) return true;
+                if (node instanceof AST_SymbolRef) {
+                    if (node.is_declared(compressor) ? node.fixed_value() || all(node.definition().orig, function(sym) {
+                        return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLet);
+                    }) : parent instanceof AST_Assign && parent.operator == "=" && parent.left === node) return false;
+                    if (!replace_all) return true;
+                    scan_rhs = false;
+                    return false;
+                }
                 if (node instanceof AST_Try) return true;
                 if (node instanceof AST_With) return true;
-                if (replace_all) return false;
-                return node instanceof AST_SymbolRef
-                    && !node.is_declared(compressor)
-                    && !(parent instanceof AST_Assign && parent.operator == "=" && parent.left === node);
+                return false;
             }
 
             function in_conditional(node, parent) {
@@ -1706,6 +1715,8 @@ merge(Compressor.prototype, {
                     extract_candidates(expr.condition);
                     extract_candidates(expr.consequent);
                     extract_candidates(expr.alternative);
+                } else if (expr instanceof AST_Definitions) {
+                    expr.definitions.forEach(extract_candidates);
                 } else if (expr instanceof AST_Dot) {
                     extract_candidates(expr.expression);
                 } else if (expr instanceof AST_DWLoop) {
@@ -1759,18 +1770,18 @@ merge(Compressor.prototype, {
                     } else {
                         extract_candidates(expr.expression);
                     }
-                } else if (expr instanceof AST_Var) {
-                    expr.definitions.forEach(extract_candidates);
                 } else if (expr instanceof AST_VarDef) {
-                    if (expr.value) {
-                        var def = expr.name.definition();
-                        if (def.references.length > def.replaced) {
-                            candidates.push(hit_stack.slice());
+                    if (expr.name instanceof AST_SymbolVar) {
+                        if (expr.value) {
+                            var def = expr.name.definition();
+                            if (def.references.length > def.replaced) {
+                                candidates.push(hit_stack.slice());
+                            }
+                        } else {
+                            declare_only[expr.name.name] = (declare_only[expr.name.name] || 0) + 1;
                         }
-                        extract_candidates(expr.value);
-                    } else {
-                        declare_only[expr.name.name] = (declare_only[expr.name.name] || 0) + 1;
                     }
+                    if (expr.value) extract_candidates(expr.value);
                 }
                 hit_stack.pop();
             }
@@ -2799,14 +2810,15 @@ merge(Compressor.prototype, {
     }
 
     function extract_declarations_from_unreachable_code(compressor, stat, target) {
-        if (!(stat instanceof AST_Defun)) {
+        if (!(stat instanceof AST_Definitions || stat instanceof AST_Defun)) {
             AST_Node.warn("Dropping unreachable code [{file}:{line},{col}]", stat.start);
         }
         var block;
         stat.walk(new TreeWalker(function(node, descend) {
             if (node instanceof AST_Definitions) {
-                AST_Node.warn("Declarations in unreachable code! [{file}:{line},{col}]", node.start);
-                node.remove_initializers(compressor);
+                if (node.remove_initializers(compressor)) {
+                    AST_Node.warn("Dropping initialization in unreachable code [{file}:{line},{col}]", node.start);
+                }
                 push(node);
                 return true;
             }
@@ -3273,7 +3285,12 @@ merge(Compressor.prototype, {
         }
 
         function warn(node) {
-            AST_Node.warn("global_defs " + node.print_to_string() + " redefined [{file}:{line},{col}]", node.start);
+            AST_Node.warn("global_defs {node} redefined [{file}:{line},{col}]", {
+                node: node,
+                file: node.start.file,
+                line: node.start.line,
+                col: node.start.col,
+            });
         }
 
         AST_Toplevel.DEFMETHOD("resolve_defines", function(compressor) {
@@ -3878,10 +3895,10 @@ merge(Compressor.prototype, {
                     return val[key].apply(val, args);
                 } catch (ex) {
                     AST_Node.warn("Error evaluating {code} [{file}:{line},{col}]", {
-                        code: this.print_to_string(),
+                        code: this,
                         file: this.start.file,
                         line: this.start.line,
-                        col: this.start.col
+                        col: this.start.col,
                     });
                 } finally {
                     if (val instanceof RegExp) val.lastIndex = 0;
@@ -4452,6 +4469,11 @@ merge(Compressor.prototype, {
                 pop();
                 return true;
             }
+            if (node instanceof AST_Break) {
+                var target = tw.loopcontrol_target(node);
+                if (!(target instanceof AST_IterationStatement)) insert(target);
+                return true;
+            }
             if (node instanceof AST_Conditional) {
                 node.condition.walk(tw);
                 push();
@@ -4471,20 +4493,7 @@ merge(Compressor.prototype, {
             }
             if (node instanceof AST_Continue) {
                 var target = tw.loopcontrol_target(node);
-                if (!(target instanceof AST_Do)) return true;
-                var stack = [];
-                while (!HOP(segment, "block") || segment.block !== target) {
-                    stack.push(segment);
-                    pop();
-                }
-                segment.loop = "c";
-                push();
-                while (stack.length) {
-                    var seg = stack.pop();
-                    push();
-                    if (HOP(seg, "block")) segment.block = seg.block;
-                    if (HOP(seg, "loop")) segment.loop = seg.loop;
-                }
+                if (target instanceof AST_Do) insert(target);
                 return true;
             }
             if (node instanceof AST_Do) {
@@ -4493,7 +4502,7 @@ merge(Compressor.prototype, {
                 segment.loop = true;
                 var save = segment;
                 node.body.walk(tw);
-                if (segment.loop == "c") segment = save;
+                if (segment.inserted === node) segment = save;
                 node.condition.walk(tw);
                 pop();
                 return true;
@@ -4534,7 +4543,9 @@ merge(Compressor.prototype, {
             if (node instanceof AST_LabeledStatement) {
                 push();
                 segment.block = node;
+                var save = segment;
                 node.body.walk(tw);
+                if (segment.inserted === node) segment = save;
                 pop();
                 return true;
             }
@@ -4570,7 +4581,10 @@ merge(Compressor.prototype, {
                 segment = save;
                 node.body.forEach(function(branch) {
                     push();
+                    segment.block = node;
+                    var save = segment;
                     walk_body(branch, tw);
+                    if (segment.inserted === node) segment = save;
                     pop();
                 });
                 return true;
@@ -4725,6 +4739,27 @@ merge(Compressor.prototype, {
             });
         }
 
+        function insert(target) {
+            var stack = [];
+            while (true) {
+                if (HOP(segment, "block")) {
+                    var block = segment.block;
+                    if (block instanceof AST_LabeledStatement) block = block.body;
+                    if (block === target) break;
+                }
+                stack.push(segment);
+                pop();
+            }
+            segment.inserted = segment.block;
+            push();
+            while (stack.length) {
+                var seg = stack.pop();
+                push();
+                if (HOP(seg, "block")) segment.block = seg.block;
+                if (HOP(seg, "loop")) segment.loop = seg.loop;
+            }
+        }
+
         function must_visit(base, segment) {
             return base === segment || base.isPrototypeOf(segment);
         }
@@ -4992,7 +5027,7 @@ merge(Compressor.prototype, {
                         var old_def, var_defs = var_defs_by_id.get(sym.id);
                         if (!def.value) {
                             if (var_defs.length > 1) {
-                                AST_Node.warn("Dropping duplicated declaration of variable {name} [{file}:{line},{col}]", template(def.name));
+                                AST_Node.info("Dropping declaration of variable {name} [{file}:{line},{col}]", template(def.name));
                                 remove(var_defs, def);
                                 sym.eliminated++;
                             } else {
@@ -5183,7 +5218,10 @@ merge(Compressor.prototype, {
                 var def = sym.definition();
                 if (!def) return;
                 if (def.id in in_use_ids) return;
-                if (def.scope !== self && self.find_variable(sym) === def) return;
+                if (def.scope !== self) {
+                    var d = self.find_variable(sym);
+                    if ((d && d.redefined() || d) === def) return;
+                }
                 log(sym, "Dropping unused loop variable {name}");
                 if (for_ins[def.id] === node) delete for_ins[def.id];
                 var body = [];
@@ -5226,7 +5264,7 @@ merge(Compressor.prototype, {
                 name: sym.name,
                 file: sym.start.file,
                 line: sym.start.line,
-                col : sym.start.col
+                col : sym.start.col,
             };
         }
 
@@ -6662,19 +6700,21 @@ merge(Compressor.prototype, {
         this.definitions.forEach(function(def) {
             def.value = make_node(AST_Undefined, def).optimize(compressor);
         });
+        return true;
     });
 
-    AST_Let.DEFMETHOD("remove_initializers", function() {
+    function remove_initializers() {
+        var CHANGED = false;
         this.definitions.forEach(function(def) {
+            if (!def.value) return;
             def.value = null;
+            CHANGED = true;
         });
-    });
+        return CHANGED;
+    }
 
-    AST_Var.DEFMETHOD("remove_initializers", function() {
-        this.definitions.forEach(function(def) {
-            def.value = null;
-        });
-    });
+    AST_Let.DEFMETHOD("remove_initializers", remove_initializers);
+    AST_Var.DEFMETHOD("remove_initializers", remove_initializers);
 
     AST_Definitions.DEFMETHOD("to_assignments", function(compressor) {
         var reduce_vars = compressor.option("reduce_vars");
@@ -6827,7 +6867,7 @@ merge(Compressor.prototype, {
                             length: length,
                             file: self.start.file,
                             line: self.start.line,
-                            col: self.start.col
+                            col: self.start.col,
                         });
                         break;
                     }
@@ -6884,10 +6924,10 @@ merge(Compressor.prototype, {
                         }));
                     } catch (ex) {
                         AST_Node.warn("Error converting {expr} [{file}:{line},{col}]", {
-                            expr: self.print_to_string(),
+                            expr: self,
                             file: self.start.file,
                             line: self.start.line,
-                            col: self.start.col
+                            col: self.start.col,
                         });
                     }
                 }
@@ -7598,7 +7638,9 @@ merge(Compressor.prototype, {
                 // typeof always returns a non-empty string, thus it's
                 // always true in booleans
                 AST_Node.warn("Boolean expression always true [{file}:{line},{col}]", self.start);
-                return (exp instanceof AST_SymbolRef ? make_node(AST_True, self) : make_sequence(self, [
+                return (exp instanceof AST_SymbolRef && all(exp.definition().orig, function(sym) {
+                    return !(sym instanceof AST_SymbolConst || sym instanceof AST_SymbolLet);
+                }) ? make_node(AST_True, self) : make_sequence(self, [
                     exp,
                     make_node(AST_True, self)
                 ])).optimize(compressor);
@@ -9300,7 +9342,7 @@ merge(Compressor.prototype, {
                 prop: self.property,
                 file: self.start.file,
                 line: self.start.line,
-                col: self.start.col
+                col: self.start.col,
             });
         }
         var parent = compressor.parent();

lib/minify.js

@@ -33,7 +33,9 @@ function read_source_map(name, toplevel) {
             return to_ascii(match[2]);
         }
     }
-    AST_Node.warn("inline source map not found: " + name);
+    AST_Node.warn("inline source map not found: {name}", {
+        name: name,
+    });
 }
 
 function parse_source_map(content) {
@@ -258,6 +260,7 @@ function minify(files, options) {
     } catch (ex) {
         return { error: ex };
     } finally {
+        AST_Node.log_function();
         AST_Node.disable_validation();
     }
 }

lib/utils.js

@@ -143,8 +143,9 @@ function push_uniq(array, el) {
 }
 
 function string_template(text, props) {
-    return text.replace(/\{(.+?)\}/g, function(str, p) {
-        return props && props[p];
+    return text.replace(/\{([^}]+)\}/g, function(str, p) {
+        var value = props[p];
+        return value instanceof AST_Node ? value.print_to_string() : value;
     });
 }
 

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": "3.11.4",
+  "version": "3.11.5",
   "engines": {
     "node": ">=0.8.0"
   },

test/compress.js

@@ -315,6 +315,7 @@ function test_case(test) {
         if (test.mangle.properties) U.mangle_properties(output, test.mangle.properties);
     }
     var output_code = make_code(output, output_options);
+    U.AST_Node.log_function();
     if (expect != output_code) {
         log([
             "!!! failed",
@@ -386,7 +387,7 @@ function test_case(test) {
             mangle: test.mangle
         });
         var actual = stdout[toplevel ? 1 : 0];
-        if (test.expect_stdout === true) {
+        if (test.expect_stdout === true || test.expect_stdout instanceof Error && test.expect_stdout.name === actual.name) {
             test.expect_stdout = actual;
         }
         if (!sandbox.same_stdout(test.expect_stdout, actual)) {

test/compress/collapse_vars.js

@@ -8577,3 +8577,28 @@ issue_4242: {
     }
     expect_stdout: "undefined"
 }
+
+issue_4248: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = 0;
+        try {
+            a = 1;
+            b[1];
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect: {
+        var a = 0;
+        try {
+            a = 1;
+            b[1];
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect_stdout: "1"
+}

test/compress/conditionals.js

@@ -83,13 +83,11 @@ ifs_3_should_warn: {
         "WARN: Condition left of && always false [test/compress/conditionals.js:3,12]",
         "WARN: Condition always false [test/compress/conditionals.js:3,12]",
         "WARN: Dropping unreachable code [test/compress/conditionals.js:3,34]",
-        "WARN: Declarations in unreachable code! [test/compress/conditionals.js:4,12]",
         "WARN: + in boolean context always true [test/compress/conditionals.js:10,19]",
         "WARN: Boolean || always true [test/compress/conditionals.js:10,12]",
         "WARN: Condition left of || always true [test/compress/conditionals.js:10,12]",
         "WARN: Condition always true [test/compress/conditionals.js:10,12]",
         "WARN: Dropping unreachable code [test/compress/conditionals.js:12,15]",
-        "WARN: Declarations in unreachable code! [test/compress/conditionals.js:13,12]",
         "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:3,12]",
         "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:10,12]",
     ]

test/compress/const.js

@@ -1084,3 +1084,54 @@ issue_4231: {
     }
     expect_stdout: "function"
 }
+
+issue_4245: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        const a = f();
+        function f() {
+            typeof a;
+        }
+    }
+    expect: {
+        const a = f();
+        function f() {
+            a,
+            1;
+        }
+    }
+    expect_stdout: true
+}
+
+issue_4248: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            (function() {
+                a = "PASS";
+                b[a];
+                const b = 0;
+            })();
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect: {
+        var a = "FAIL";
+        try {
+            (function() {
+                a = "PASS";
+                b[a];
+                const b = 0;
+            })();
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect_stdout: "PASS"
+}

test/compress/dead-code.js

@@ -61,8 +61,6 @@ dead_code_2_should_warn: {
     expect_stdout: true
     expect_warnings: [
         "WARN: Dropping unreachable code [test/compress/dead-code.js:8,12]",
-        "WARN: Declarations in unreachable code! [test/compress/dead-code.js:10,16]",
-        "WARN: Dropping unreachable code [test/compress/dead-code.js:10,16]",
     ]
     node_version: "<=4"
 }
@@ -103,11 +101,9 @@ dead_code_constant_boolean_should_warn_more: {
         "WARN: + in boolean context always true [test/compress/dead-code.js:1,33]",
         "WARN: Boolean || always true [test/compress/dead-code.js:1,16]",
         "WARN: Dropping unreachable code [test/compress/dead-code.js:1,45]",
-        "WARN: Declarations in unreachable code! [test/compress/dead-code.js:3,12]",
         "WARN: Boolean expression always true [test/compress/dead-code.js:6,47]",
         "WARN: Boolean && always false [test/compress/dead-code.js:6,28]",
         "WARN: Dropping unreachable code [test/compress/dead-code.js:6,63]",
-        "WARN: Declarations in unreachable code! [test/compress/dead-code.js:9,12]",
         "WARN: Dropping side-effect-free statement [test/compress/dead-code.js:1,15]",
         "WARN: Dropping side-effect-free statement [test/compress/dead-code.js:6,28]",
     ]

test/compress/ie8.js

@@ -2877,3 +2877,30 @@ issue_4235: {
     }
     expect_stdout: "undefined"
 }
+
+issue_4250: {
+    options = {
+        ie8: true,
+        loops: true,
+        unused: true,
+    }
+    input: {
+        console.log(function f() {
+            (function() {
+                for (f in "f");
+            })();
+            return f;
+            var f;
+        }());
+    }
+    expect: {
+        console.log(function f() {
+            (function() {
+                for (f in "f");
+            })();
+            return f;
+            var f;
+        }());
+    }
+    expect_stdout: "0"
+}

test/compress/issue-1034.js

@@ -39,7 +39,7 @@ non_hoisted_function_after_return: {
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:4,16]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:7,16]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:10,12]",
-        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:11,21]"
+        "WARN: Dropping unused function UnusedFunction [test/compress/issue-1034.js:11,21]",
     ]
 }
 
@@ -84,15 +84,12 @@ non_hoisted_function_after_return_2a: {
         }
     }
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:4,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:4,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:7,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:7,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:4,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:7,16]",
         "WARN: Dropping unused variable a [test/compress/issue-1034.js:4,20]",
         "WARN: Dropping unused function nope [test/compress/issue-1034.js:11,21]",
         "INFO: pass 0: last_count: Infinity, count: 35",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:9,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:9,12]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:9,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:12,12]",
         "INFO: Dropping unused variable b [test/compress/issue-1034.js:7,20]",
         "INFO: Dropping unused variable c [test/compress/issue-1034.js:9,16]",
@@ -138,10 +135,7 @@ non_hoisted_function_after_return_2b: {
         }
     }
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:6,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:6,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:8,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:8,12]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:8,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:12,12]",
     ]
 }
@@ -242,15 +236,12 @@ non_hoisted_function_after_return_2a_strict: {
     }
     expect_stdout: "5 6"
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:5,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:5,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:8,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:8,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:5,16]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:8,16]",
         "WARN: Dropping unused variable a [test/compress/issue-1034.js:5,20]",
         "WARN: Dropping unused function nope [test/compress/issue-1034.js:12,21]",
         "INFO: pass 0: last_count: Infinity, count: 46",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:10,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:10,12]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:10,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:13,12]",
         "INFO: Dropping unused variable b [test/compress/issue-1034.js:8,20]",
         "INFO: Dropping unused variable c [test/compress/issue-1034.js:10,16]",
@@ -301,10 +292,7 @@ non_hoisted_function_after_return_2b_strict: {
     }
     expect_stdout: "5 6"
     expect_warnings: [
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:7,16]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:7,16]",
-        "WARN: Dropping unreachable code [test/compress/issue-1034.js:9,12]",
-        "WARN: Declarations in unreachable code! [test/compress/issue-1034.js:9,12]",
+        "WARN: Dropping initialization in unreachable code [test/compress/issue-1034.js:9,12]",
         "WARN: Dropping unreachable code [test/compress/issue-1034.js:13,12]",
     ]
 }

test/compress/let.js

@@ -893,3 +893,60 @@ issue_4231: {
     expect_stdout: "function"
     node_version: ">=4"
 }
+
+issue_4245: {
+    options = {
+        booleans: true,
+    }
+    input: {
+        "use strict";
+        let a = f();
+        function f() {
+            typeof a;
+        }
+    }
+    expect: {
+        "use strict";
+        let a = f();
+        function f() {
+            a,
+            1;
+        }
+    }
+    expect_stdout: ReferenceError("a is not defined")
+    node_version: ">=4"
+}
+
+issue_4248: {
+    options = {
+        collapse_vars: true,
+    }
+    input: {
+        var a = "FAIL";
+        try {
+            (function() {
+                "use strict";
+                a = "PASS";
+                b[a];
+                let b;
+            })();
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect: {
+        var a = "FAIL";
+        try {
+            (function() {
+                "use strict";
+                a = "PASS";
+                b[a];
+                let b;
+            })();
+        } catch (e) {
+            console.log(a);
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}

test/compress/merge_vars.js

@@ -3092,3 +3092,94 @@ issue_4237_2: {
     }
     expect_stdout: "PASS"
 }
+
+issue_4253: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        switch (0) {
+          default:
+            var a = "FAIL";
+            a = a && a;
+            try {
+                break;
+            } catch (e) {}
+            var b = 42;
+        }
+        console.log(b);
+    }
+    expect: {
+        switch (0) {
+          default:
+            var a = "FAIL";
+            a = a && a;
+            try {
+                break;
+            } catch (e) {}
+            var b = 42;
+        }
+        console.log(b);
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4255: {
+    options = {
+        dead_code: true,
+        loops: true,
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        L: for (var a = 2; --a;)
+            for (var b = 0; console.log(b); --b)
+                break L;
+    }
+    expect: {
+        L: for (var a = 2; --a;) {
+            var b = 0;
+            if (console.log(b))
+                break L;
+        }
+    }
+    expect_stdout: "0"
+}
+
+issue_4257: {
+    options = {
+        merge_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = 0;
+        for (var i = 0; i < 2; i++)
+            switch (--a) {
+              case 0:
+                var b = 0;
+                break;
+              case 0:
+              default:
+                var c = 1 + (0 | (b && A));
+                console.log(c);
+            }
+    }
+    expect: {
+        var a = 0;
+        for (var i = 0; i < 2; i++)
+            switch (--a) {
+              case 0:
+                var b = 0;
+                break;
+              case 0:
+              default:
+                var c = 1 + (0 | (b && A));
+                console.log(c);
+            }
+    }
+    expect_stdout: [
+        "1",
+        "1",
+    ]
+}

test/reduce.js

@@ -593,7 +593,7 @@ function is_error(result) {
 }
 
 function is_timed_out(result) {
-    return is_error(result) && /timed out/.test(result);
+    return is_error(result) && /timed out/.test(result.message);
 }
 
 function is_statement(node) {

test/ufuzz/index.js

@@ -1369,7 +1369,12 @@ for (var round = 1; round <= num_iterations; round++) {
                 }
             }
             // ignore difference in error message caused by Temporal Dead Zone
-            if (!ok && errored) ok = uglify_result.name == "ReferenceError" && original_result.name == "ReferenceError";
+            if (!ok && errored && uglify_result.name == "ReferenceError" && original_result.name == "ReferenceError") ok = true;
+            // ignore spurious time-outs
+            if (!ok && errored && /timed out/.test(original_result.message) && !/timed out/.test(uglify_result.message)) {
+                if (!orig_result[toplevel ? 3 : 2]) orig_result[toplevel ? 3 : 2] = sandbox.run_code(original_code, toplevel, 10000);
+                ok = sandbox.same_stdout(orig_result[toplevel ? 3 : 2], uglify_result);
+            }
             // ignore difference in error message caused by `in`
             // ignore difference in depth of termination caused by infinite recursion
             if (!ok) {