fix, less with compression (-x) was unable to parse auto\9

lib/less/parser.js

@@ -1197,19 +1197,19 @@ less.Parser = function Parser(env) {
                     restore();
                 }
             },
-            rule: function () {
+            rule: function (tryAnonymous) {
                 var name, value, c = input.charAt(i), important, match;
                 save();
 
                 if (c === '.' || c === '#' || c === '&') { return }
 
                 if (name = $(this.variable) || $(this.property)) {
-                    if (!env.compress && (name.charAt(0) != '@') && (match = /^([^@+\/'"*`(;{}-]*);/.exec(chunks[j]))) {
-                        i += match[0].length - 1;
-                        value = new(tree.Anonymous)(match[1]);
-                    } else {
-                        value = $(this.value);
-                    }
+                    // prefer to try to parse first if its a variable or we are compressing
+                    // but always fallback on the other one
+                    value = !tryAnonymous && (env.compress || (name.charAt(0) === '@')) ?
+                        ($(this.value) || $(this.anonymousValue)) :
+                        ($(this.anonymousValue) || $(this.value));
+
                     important = $(this.important);
 
                     if (value && $(this.end)) {
@@ -1217,9 +1217,18 @@ less.Parser = function Parser(env) {
                     } else {
                         furthest = i;
                         restore();
+                        if (value && !tryAnonymous) {
+                            return this.rule(true);
+                        }
                     }
                 }
             },
+            anonymousValue: function () {
+                if (match = /^([^@+\/'"*`(;{}-]*);/.exec(chunks[j])) {
+                    i += match[0].length - 1;
+                    return new(tree.Anonymous)(match[1]);
+                }
+            },
 
             //
             // An @import directive

test/css/compression/compression.css

@@ -1,2 +1,2 @@
 #colours{color1:#fea;color2:#fea;color3:rgba(255,238,170,0.1);string:"#ffeeaa"}
-dimensions{val:.1px;val:0;val:4cm;val:.2;val:5;angles-must-have-unit:0deg}
+dimensions{val:.1px;val:0;val:4cm;val:.2;val:5;angles-must-have-unit:0deg;width:auto\9}

test/css/css.css

@@ -74,6 +74,7 @@ p + h1 {
   background: -webkit-gradient(linear, left top, left bottom, from(#ff0000), to(#0000ff));
   margin: ;
   filter: alpha(opacity=100);
+  width: auto\9;
 }
 .misc .nested-multiple {
   multiple-semi-colons: yes;

test/less/compression/compression.less

@@ -12,4 +12,5 @@ dimensions {
   val: 0.2;
   val: 5;
   angles-must-have-unit: 0deg;
+  width: auto\9;
 }

test/less/css.less

@@ -85,6 +85,7 @@ p + h1 {
 	multiple-semi-colons: yes;;;;;;
   };
   filter: alpha(opacity=100);
+  width: auto\9;
 }
 
 #important {