From 5d49ca000e18dd6c30a5486fb62f49e01850cc5b Mon Sep 17 00:00:00 2001
From: Luke Page <luke.a.page@gmail.com>
Date: Mon, 6 Aug 2012 22:02:32 +0100
Subject: [PATCH] Eval assignments by copying. Fixes #534

---
 lib/less/tree/assignment.js | 4 +++-
 test/css/ie-filters.css     | 4 ++++
 test/less/ie-filters.less   | 7 +++++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/lib/less/tree/assignment.js b/lib/less/tree/assignment.js
index 70ce6e2f..a5559ada 100644
--- a/lib/less/tree/assignment.js
+++ b/lib/less/tree/assignment.js
@@ -9,7 +9,9 @@ tree.Assignment.prototype = {
         return this.key + '=' + (this.value.toCSS ? this.value.toCSS() : this.value);
     },
     eval: function (env) {
-        if (this.value.eval) { this.value = this.value.eval(env) }
+        if (this.value.eval) {
+            return new(tree.Assignment)(this.key, this.value.eval(env));
+        }
         return this;
     }
 };
diff --git a/test/css/ie-filters.css b/test/css/ie-filters.css
index a5c5795a..007aa536 100644
--- a/test/css/ie-filters.css
+++ b/test/css/ie-filters.css
@@ -3,3 +3,7 @@
   filter: progid:DXImageTransform.Microsoft.Alpha(opacity=0);
   filter: progid:DXImageTransform.Microsoft.gradient(startColorstr="#333333", endColorstr="#000000", GradientType=0);
 }
+.evalTest1 {
+  filter: progid:DXImageTransform.Microsoft.Alpha(opacity=30);
+  filter: progid:DXImageTransform.Microsoft.Alpha(opacity=5);
+}
diff --git a/test/less/ie-filters.less b/test/less/ie-filters.less
index bea85b82..3350b653 100644
--- a/test/less/ie-filters.less
+++ b/test/less/ie-filters.less
@@ -5,4 +5,11 @@
   filter: progid:DXImageTransform.Microsoft.Alpha(opacity = 20);
   filter: progid:DXImageTransform.Microsoft.Alpha(opacity=@fat);
   filter: progid:DXImageTransform.Microsoft.gradient(startColorstr="#333333", endColorstr=@cloudhead, GradientType=@fat);
+}
+.evalTest(@arg) {
+  filter: progid:DXImageTransform.Microsoft.Alpha(opacity=@arg);
+}
+.evalTest1 {
+  .evalTest(30);
+  .evalTest(5);
 }
\ No newline at end of file