Added support for default variables

lib/less/parser.js

@@ -1155,7 +1155,7 @@ less.Parser = function Parser(env) {
                 }
             },
             rule: function () {
-                var name, value, c = input.charAt(i), important, match;
+                var name, value, c = input.charAt(i), important, isDefault, match;
                 save();
 
                 if (c === '.' || c === '#' || c === '&') { return }
@@ -1170,9 +1170,10 @@ less.Parser = function Parser(env) {
                         value = $(this.value);
                     }
                     important = $(this.important);
+                    isDefault = $(this.isDefault);
 
                     if (value && $(this.end)) {
-                        return new(tree.Rule)(name, value, important, memo);
+                        return new(tree.Rule)(name, value, important, memo, null, isDefault);
                     } else {
                         furthest = i;
                         restore();
@@ -1391,6 +1392,11 @@ less.Parser = function Parser(env) {
                     return $(/^! *important/);
                 }
             },
+            isDefault: function () {
+                if (input.charAt(i) === '!') {
+                    return $(/^! *default/);
+                }
+            },
             sub: function () {
                 var e;
 

lib/less/tree/rule.js

@@ -1,6 +1,6 @@
 (function (tree) {
 
-tree.Rule = function (name, value, important, index, inline) {
+tree.Rule = function (name, value, important, index, inline, isDefault) {
     this.name = name;
     this.value = (value instanceof tree.Value) ? value : new(tree.Value)([value]);
     this.important = important ? ' ' + important.trim() : '';
@@ -9,7 +9,10 @@ tree.Rule = function (name, value, important, index, inline) {
 
     if (name.charAt(0) === '@') {
         this.variable = true;
-    } else { this.variable = false }
+        this.isDefault = isDefault;
+    } else {
+      this.variable = false;
+    }
 };
 tree.Rule.prototype.toCSS = function (env) {
     if (this.variable) { return "" }
@@ -24,14 +27,18 @@ tree.Rule.prototype.eval = function (context) {
     return new(tree.Rule)(this.name,
                           this.value.eval(context),
                           this.important,
-                          this.index, this.inline);
+                          this.index,
+                          this.inline,
+                          this.isDefault);
 };
 
 tree.Rule.prototype.makeImportant = function () {
     return new(tree.Rule)(this.name,
                           this.value,
                           "!important",
-                          this.index, this.inline);
+                          this.index,
+                          this.inline,
+                          this.isDefault);
 };
 
 tree.Shorthand = function (a, b) {

lib/less/tree/ruleset.js

@@ -105,7 +105,9 @@ tree.Ruleset.prototype = {
         else {
             return this._variables = this.rules.reduce(function (hash, r) {
                 if (r instanceof tree.Rule && r.variable === true) {
-                    hash[r.name] = r;
+                    if (!r.isDefault || !(r.name in hash)) {
+                        hash[r.name] = r;
+                    }
                 }
                 return hash;
             }, {});

test/css/variables.css

@@ -31,3 +31,7 @@ a:nth-child(2) {
 .testPollution {
   a: 'pollution';
 }
+.defaults {
+  font-size: 14px;
+  line-height: 14px;
+}

test/less/variables.less

@@ -66,3 +66,12 @@ a:nth-child(@a) {
 	.polluteMixin();
 	a: @a;
 }
+
+@baseFontSize: 14px;
+@baseFontSize: 12px !default;
+@baseLineHeight: 14px;
+
+.defaults {
+  font-size: @baseFontSize;
+  line-height: @baseLineHeight;
+}