v2.4.4

`String(x + 5)` is not always the same as `x + "5"`.  Overlooked that. :-(

Close #350

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);
         }
@@ -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 == "+") {

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": "2.4.4",
     "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;
     }
 }