Convert property merging to the new agreed syntax of +:

lib/less/parser.js

@@ -1230,12 +1230,12 @@ less.Parser = function Parser(env) {
                 }
             },
             rule: function (tryAnonymous) {
-                var name, value, c = input.charAt(i), important, merge, match;
+                var name, value, c = input.charAt(i), important, merge = false, match;
                 save();
 
                 if (c === '.' || c === '#' || c === '&') { return }
 
-                if (name = $(this.variable) || $(this.property)) {
+                if (name = $(this.variable) || $(this.ruleProperty)) {
                     // prefer to try to parse first if its a variable or we are compressing
                     // but always fallback on the other one
                     value = !tryAnonymous && (env.compress || (name.charAt(0) === '@')) ?
@@ -1244,7 +1244,10 @@ less.Parser = function Parser(env) {
 
 
                     important = $(this.important);
-                    merge = $(this.merge);
+                    if (name[name.length-1] === "+") {
+                        merge = true;
+                        name = name.substr(0, name.length - 1);
+                    }
 
                     if (value && $(this.end)) {
                         return new (tree.Rule)(name, value, important, merge, memo, env.currentFileInfo);
@@ -1497,21 +1500,6 @@ less.Parser = function Parser(env) {
                     return $(/^! *important/);
                 }
             },
-            merge: function () {
-                var separator;
-                if (input.charAt(i) === '!') {
-                    if ($(/^! *merge\(/)) {
-                        separator = expect(/^ *space|comma */);
-						if (separator) {
-						    separator = (separator.trim() === 'space')
-						        ? ' ' 
-							    : ',';
-						}
-                        expect(')');
-                    }
-                }
-                return separator;
-            },
             sub: function () {
                 var a, e;
 
@@ -1632,6 +1620,13 @@ less.Parser = function Parser(env) {
                 if (name = $(/^(\*?-?[_a-z0-9-]+)\s*:/)) {
                     return name[1];
                 }
+            },
+            ruleProperty: function () {
+                var name;
+
+                if (name = $(/^(\*?-?[_a-z0-9-]+)\s*(\+?)\s*:/)) {
+                    return name[1] + (name[2] || "");
+                }
             }
         }
     };

lib/less/tree/rule.js

@@ -20,7 +20,7 @@ tree.Rule.prototype = {
         this.value = visitor.visit(this.value);
     },
     toCSS: function (env) {
-        if (this.variable) { return "" }
+        if (this.variable) { return ""; }
         else {
             try {
                 return this.name + (env.compress ? ':' : ': ') +

lib/less/tree/ruleset.js

@@ -178,7 +178,8 @@ tree.Ruleset.prototype = {
             debugInfo,     // Line number debugging
             rule;
 
-            this.mergeRules();
+        this.mergeRules();
+
         // Compile rules and rulesets
         for (var i = 0; i < this.rules.length; i++) {
             rule = this.rules[i];
@@ -468,8 +469,7 @@ tree.Ruleset.prototype = {
 
             if ((rule instanceof tree.Rule) && rule.merge) {
                 key = [rule.name,
-                       rule.important ? "!" : "",
-                       rule.merge].join(",");
+                       rule.important ? "!" : ""].join(",");
 
                 if (!groups[key]) {
                     parts = groups[key] = [];
@@ -487,7 +487,7 @@ tree.Ruleset.prototype = {
             if (parts.length > 1) {
 				rule = parts[0];
 				
-				rule.value = new ((rule.merge === ' ') ? tree.Expression : tree.Value)(parts.map(function (p) {
+				rule.value = new (tree.Value)(parts.map(function (p) {
 					return p.value;
 				}));
             }