Properly scope catch identifier when --screw-ie8

Fix #344

bin/uglifyjs

@@ -62,6 +62,7 @@ You need to pass an argument to this option to specify the name that your module
     .describe("lint", "Display some scope warnings")
     .describe("v", "Verbose")
     .describe("V", "Print version number and exit.")
+    .describe("noerr", "Don't throw an error for unknown options in -c, -b or -m.")
 
     .alias("p", "prefix")
     .alias("o", "output")
@@ -96,6 +97,7 @@ You need to pass an argument to this option to specify the name that your module
     .boolean("spidermonkey")
     .boolean("lint")
     .boolean("V")
+    .boolean("noerr")
 
     .wrap(80)
 
@@ -104,6 +106,12 @@ You need to pass an argument to this option to specify the name that your module
 
 normalize(ARGS);
 
+if (ARGS.noerr) {
+    UglifyJS.DefaultsError.croak = function(msg, defs) {
+        sys.error("WARN: " + msg);
+    };
+}
+
 if (ARGS.version || ARGS.V) {
     var json = require("../package.json");
     sys.puts(json.name + ' ' + json.version);

lib/ast.js

@@ -498,12 +498,6 @@ var AST_Try = DEFNODE("Try", "bcatch bfinally", {
     }
 }, AST_Block);
 
-// XXX: this is wrong according to ECMA-262 (12.4).  the catch block
-// should introduce another scope, as the argname should be visible
-// only inside the catch block.  However, doing it this way because of
-// IE which simply introduces the name in the surrounding scope.  If
-// we ever want to fix this then AST_Catch should inherit from
-// AST_Scope.
 var AST_Catch = DEFNODE("Catch", "argname", {
     $documentation: "A `catch` node; only makes sense as part of a `try` statement",
     $propdoc: {
@@ -515,7 +509,7 @@ var AST_Catch = DEFNODE("Catch", "argname", {
             walk_body(this, visitor);
         });
     }
-}, AST_Block);
+}, AST_Scope);
 
 var AST_Finally = DEFNODE("Finally", null, {
     $documentation: "A `finally` node; only makes sense as part of a `try` statement"

lib/compress.js

@@ -85,13 +85,14 @@ merge(Compressor.prototype, {
     },
     before: function(node, descend, in_list) {
         if (node._squeezed) return node;
+        var was_scope = false;
         if (node instanceof AST_Scope) {
-            //node.drop_unused(this);
             node = node.hoist_declarations(this);
+            was_scope = true;
         }
         descend(node, this);
         node = node.optimize(this);
-        if (node instanceof AST_Scope) {
+        if (was_scope && node instanceof AST_Scope) {
             node.drop_unused(this);
             descend(node, this);
         }
@@ -1668,10 +1669,10 @@ merge(Compressor.prototype, {
                                 return arg.value;
                             }).join(",") + "){" + self.args[self.args.length - 1].value + "})()";
                             var ast = parse(code);
-                            ast.figure_out_scope();
+                            ast.figure_out_scope({ screw_ie8: compressor.option("screw_ie8") });
                             var comp = new Compressor(compressor.options);
                             ast = ast.transform(comp);
-                            ast.figure_out_scope();
+                            ast.figure_out_scope({ screw_ie8: compressor.option("screw_ie8") });
                             ast.mangle_names();
                             var fun;
                             try {
@@ -1865,6 +1866,14 @@ merge(Compressor.prototype, {
         return self.evaluate(compressor)[0];
     });
 
+    function has_side_effects_or_prop_access(node, compressor) {
+        var save_pure_getters = compressor.option("pure_getters");
+        compressor.options.pure_getters = false;
+        var ret = node.has_side_effects(compressor);
+        compressor.options.pure_getters = save_pure_getters;
+        return ret;
+    }
+
     AST_Binary.DEFMETHOD("lift_sequences", function(compressor){
         if (compressor.option("sequences")) {
             if (this.left instanceof AST_Seq) {
@@ -1876,8 +1885,8 @@ merge(Compressor.prototype, {
                 return seq;
             }
             if (this.right instanceof AST_Seq
-                && !(this.operator == "||" || this.operator == "&&")
-                && !this.left.has_side_effects(compressor)) {
+                && this instanceof AST_Assign
+                && !has_side_effects_or_prop_access(this.left, compressor)) {
                 var seq = this.right;
                 var x = seq.to_array();
                 this.right = x.pop();
@@ -2022,16 +2031,6 @@ merge(Compressor.prototype, {
             && self.right.getValue() === "" && self.left instanceof AST_Binary
             && self.left.operator == "+" && self.left.is_string(compressor)) {
             return self.left;
-        } else if (self.operator == "+" && self.right instanceof AST_String
-                   && self.right.getValue() === "" && self.left instanceof AST_Binary
-                   && self.left.operator == "+" && self.left.right instanceof AST_Number) {
-            return make_node(AST_Binary, self, {
-                left: self.left.left,
-                operator: "+",
-                right: make_node(AST_String, self.right, {
-                    value: String(self.left.right.value)
-                })
-            });
         }
         if (compressor.option("evaluate")) {
             if (self.operator == "+") {

lib/scope.js

@@ -71,27 +71,28 @@ SymbolDef.prototype = {
     }
 };
 
-AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
-    // This does what ast_add_scope did in UglifyJS v1.
-    //
-    // Part of it could be done at parse time, but it would complicate
-    // the parser (and it's already kinda complex).  It's also worth
-    // having it separated because we might need to call it multiple
-    // times on the same tree.
+AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
+    options = defaults(options, {
+        screw_ie8: false
+    });
 
     // pass 1: setup scope chaining and handle definitions
     var self = this;
     var scope = self.parent_scope = null;
+    var defun = null;
     var nesting = 0;
     var tw = new TreeWalker(function(node, descend){
         if (node instanceof AST_Scope) {
             node.init_scope_vars(nesting);
             var save_scope = node.parent_scope = scope;
-            ++nesting;
+            var save_defun = defun;
+            if (!(node instanceof AST_Catch)) {
+                defun = node;
+            }
             scope = node;
-            descend();
+            ++nesting; descend(); --nesting;
             scope = save_scope;
-            --nesting;
+            defun = save_defun;
             return true;        // don't descend again in TreeWalker
         }
         if (node instanceof AST_Directive) {
@@ -108,7 +109,7 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
             node.scope = scope;
         }
         if (node instanceof AST_SymbolLambda) {
-            scope.def_function(node);
+            defun.def_function(node);
         }
         else if (node instanceof AST_SymbolDefun) {
             // Careful here, the scope where this should be defined is
@@ -116,22 +117,17 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(){
             // scope when we encounter the AST_Defun node (which is
             // instanceof AST_Scope) but we get to the symbol a bit
             // later.
-            (node.scope = scope.parent_scope).def_function(node);
+            (node.scope = defun.parent_scope).def_function(node);
         }
         else if (node instanceof AST_SymbolVar
                  || node instanceof AST_SymbolConst) {
-            var def = scope.def_variable(node);
+            var def = defun.def_variable(node);
             def.constant = node instanceof AST_SymbolConst;
             def.init = tw.parent().value;
         }
         else if (node instanceof AST_SymbolCatch) {
-            // XXX: this is wrong according to ECMA-262 (12.4).  the
-            // `catch` argument name should be visible only inside the
-            // catch block.  For a quick fix AST_Catch should inherit
-            // from AST_Scope.  Keeping it this way because of IE,
-            // which doesn't obey the standard. (it introduces the
-            // identifier in the enclosing scope)
-            scope.def_variable(node);
+            (options.screw_ie8 ? scope : defun)
+                .def_variable(node);
         }
     });
     self.walk(tw);

lib/utils.js

@@ -86,12 +86,16 @@ function DefaultsError(msg, defs) {
     this.defs = defs;
 };
 
+DefaultsError.croak = function(msg, defs) {
+    throw new DefaultsError(msg, defs);
+};
+
 function defaults(args, defs, croak) {
     if (args === true)
         args = {};
     var ret = args || {};
     if (croak) for (var i in ret) if (ret.hasOwnProperty(i) && !defs.hasOwnProperty(i))
-        throw new DefaultsError("`" + i + "` is not a supported option", defs);
+        DefaultsError.croak("`" + i + "` is not a supported option", defs);
     for (var i in defs) if (defs.hasOwnProperty(i)) {
         ret[i] = (args && args.hasOwnProperty(i)) ? args[i] : defs[i];
     }

package.json

@@ -3,7 +3,7 @@
     "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
     "homepage": "http://lisperator.net/uglifyjs",
     "main": "tools/node.js",
-    "version": "2.4.2",
+    "version": "2.4.6",
     "engines": { "node" : ">=0.4.0" },
     "maintainers": [{
         "name": "Mihai Bazon",

test/compress/issue-269.js

@@ -54,15 +54,13 @@ strings_concat: {
 	input: {
 		f(
 			String(x + 'str'),
-			String('str' + x),
-			String(x + 5)
+			String('str' + x)
 		);
 	}
 	expect: {
 		f(
 			x + 'str',
-			'str' + x,
-			x + '5'
+			'str' + x
 		);
 	}
-}
+}

test/compress/sequences.js

@@ -101,10 +101,12 @@ lift_sequences_1: {
 lift_sequences_2: {
     options = { sequences: true, evaluate: true };
     input: {
-        q = 1 + (foo(), bar(), 5) + 7 * (5 / (3 - (a(), (QW=ER), c(), 2))) - (x(), y(), 5);
+        foo.x = (foo = {}, 10);
+        bar = (bar = {}, 10);
     }
     expect: {
-        foo(), bar(), a(), QW = ER, c(), x(), y(), q = 36
+        foo.x = (foo = {}, 10),
+        bar = {}, bar = 10;
     }
 }