From 4c4e2bfdcd23eabb9f3bd6e6691ad2387ddae960 Mon Sep 17 00:00:00 2001
From: Philip Harrison <philip@mailharrison.com>
Date: Fri, 10 Aug 2012 15:04:58 +0100
Subject: [PATCH] Add dppx and dpcm units to parser dimensions

dppx is currently supported by Firefox > 16.
This can be used to target retina setups:
@media (min-resolution: 2dppx) {}

http://www.w3.org/TR/css3-values/#resolution
---
 lib/less/parser.js   | 22 +++++++++++-----------
 test/css/media.css   |  5 +++++
 test/less/media.less |  6 ++++++
 3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/lib/less/parser.js b/lib/less/parser.js
index e2d529fc..8498d989 100644
--- a/lib/less/parser.js
+++ b/lib/less/parser.js
@@ -691,13 +691,13 @@ less.Parser = function Parser(env) {
                     var value, c = input.charCodeAt(i);
                     if ((c > 57 || c < 45) || c === 47) return;
 
-                    if (value = $(/^(-?\d*\.?\d+)(px|%|em|pc|ex|in|deg|s|ms|pt|cm|mm|rad|grad|turn|dpi|rem|vw|vh|vm|ch)?/)) {
+                    if (value = $(/^(-?\d*\.?\d+)(px|%|em|pc|ex|in|deg|s|ms|pt|cm|mm|rad|grad|turn|dpi|dpcm|dppx|rem|vw|vh|vm|ch)?/)) {
                         return new(tree.Dimension)(value[1], value[2]);
                     }
                 },
 
                 //
-                // A Ratio 
+                // A Ratio
                 //
                 //    16/9
                 //
@@ -707,7 +707,7 @@ less.Parser = function Parser(env) {
 
                   if (value = $(/^(\d+\/\d+)/)) {
                     return new(tree.Ratio)(value[1]);
-                  } 
+                  }
                 },
 
                 //
@@ -751,13 +751,13 @@ less.Parser = function Parser(env) {
                 var a, b;
 
                 if (! peek(/^[@\w.%-]+\/[@\w.-]+/)) return;
-                
+
                 save();
 
                 if ((a = $(this.entity)) && $('/') && (b = $(this.entity))) {
                     return new(tree.Shorthand)(a, b);
                 }
-                
+
                 restore();
             },
 
@@ -1166,18 +1166,18 @@ less.Parser = function Parser(env) {
                     hasBlock, hasIdentifier;
 
                 if (input.charAt(i) !== '@') return;
-                
+
                 if (value = $(this['import']) || $(this.media)) {
                     return value;
                 }
-                
+
                 name = $(/^@[a-z-]+/);
-                
+
                 nonVendorSpecificName = name;
                 if (name.charAt(1) == '-' && name.indexOf('-', 2) > 0) {
                     nonVendorSpecificName = "@" + name.slice(name.indexOf('-', 2) + 1);
                 }
-                
+
                 switch(nonVendorSpecificName) {
                     case "@font-face":
                         hasBlock = true;
@@ -1209,11 +1209,11 @@ less.Parser = function Parser(env) {
                         hasIdentifier = true;
                         break;
                 }
-                
+
                 if (hasIdentifier) {
                     name += " " + ($(/^[^{]+/) || '').trim();
                 }
-                
+
                 if (hasBlock)
                 {
                     if (rules = $(this.block)) {
diff --git a/test/css/media.css b/test/css/media.css
index 9ccb7214..5863f03f 100644
--- a/test/css/media.css
+++ b/test/css/media.css
@@ -143,3 +143,8 @@
     }
   }
 }
+@media (-webkit-min-device-pixel-ratio: 2), (min--moz-device-pixel-ratio: 2), (-o-min-device-pixel-ratio: 2/1), (min-resolution: 2dppx), (min-resolution: 128dpcm) {
+  .b {
+    background: red;
+  }
+}
diff --git a/test/less/media.less b/test/less/media.less
index 2e44784f..13f8d29d 100644
--- a/test/less/media.less
+++ b/test/less/media.less
@@ -144,3 +144,9 @@ body {
     }
   }
 }
+
+@media (-webkit-min-device-pixel-ratio: 2), (min--moz-device-pixel-ratio: 2), (-o-min-device-pixel-ratio: 2/1), (min-resolution: 2dppx), (min-resolution: 128dpcm) {
+  .b {
+    background: red;
+  }
+}