fixed macro compilation when a variable name is a PHP reserved keyword (closes #881)

CHANGELOG

@@ -1,5 +1,6 @@
 * 1.11.0 (2012-XX-XX)
 
+ * fixed macro compilation when a variable name is a PHP reserved keyword
  * changed the date filter behavior to always apply the default timezone, except if false is passed as the timezone
  * fixed bitwise operator precedences
  * added the template_from_string function

lib/Twig/Node/Macro.php

@@ -31,7 +31,7 @@ class Twig_Node_Macro extends Twig_Node
     {
         $arguments = array();
         foreach ($this->getNode('arguments') as $argument) {
-            $arguments[] = '$'.$argument->getAttribute('name').' = null';
+            $arguments[] = '$_'.$argument->getAttribute('name').' = null';
         }
 
         $compiler
@@ -52,7 +52,7 @@ class Twig_Node_Macro extends Twig_Node
                 $compiler
                     ->write('')
                     ->string($argument->getAttribute('name'))
-                    ->raw(' => $'.$argument->getAttribute('name'))
+                    ->raw(' => $_'.$argument->getAttribute('name'))
                     ->raw(",\n")
                 ;
             }

test/Twig/Tests/Fixtures/macros/reserved_variables.test

@@ -0,0 +1,14 @@
+--TEST--
+macro
+--TEMPLATE--
+{% from _self import test %}
+
+{% macro test(this) -%}
+    {{ this }}
+{%- endmacro %}
+
+{{ test(this) }}
+--DATA--
+return array('this' => 'foo');
+--EXPECT--
+foo

test/Twig/Tests/Node/MacroTest.php

@@ -43,10 +43,10 @@ class Twig_Tests_Node_MacroTest extends Twig_Test_NodeTestCase
         return array(
             array($node, <<<EOF
 // line 1
-public function getfoo(\$foo = null)
+public function getfoo(\$_foo = null)
 {
     \$context = \$this->env->mergeGlobals(array(
-        "foo" => \$foo,
+        "foo" => \$_foo,
     ));
 
     \$blocks = array();