From e0f20a0c4debf75f42d7b386fe888992e55751ea Mon Sep 17 00:00:00 2001
From: Fabien Potencier <fabien.potencier@gmail.com>
Date: Mon, 13 Dec 2010 15:20:03 +0100
Subject: [PATCH] enhanced the for-loop optimizer (patch from nikic)

---
 lib/Twig/NodeVisitor/Optimizer.php            |   25 +++++++++++++++----------
 test/Twig/Tests/NodeVisitor/OptimizerTest.php |   14 +++++++++++++-
 2 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/lib/Twig/NodeVisitor/Optimizer.php b/lib/Twig/NodeVisitor/Optimizer.php
index 8006cd3..005dc51 100644
--- a/lib/Twig/NodeVisitor/Optimizer.php
+++ b/lib/Twig/NodeVisitor/Optimizer.php
@@ -76,24 +76,29 @@ class Twig_NodeVisitor_Optimizer implements Twig_NodeVisitorInterface
      *
      *  * "loop" is not used in the "for" tag
      *  * and there is no include tag without the "only" attribute
-     *  * and there is no inner-for tag (in which case we would need to check parent.loop usage)
+     *  * and there is no inner-for tag (in which case we would need to check loop.parent usage)
      *
      * This method should be able to optimize for with inner-for tags.
      */
     protected function enterOptimizeFor($node, $env)
     {
         if ($node instanceof Twig_Node_For) {
+            // disable the loop variable by default
             $node->setAttribute('with_loop', false);
-
-            if ($this->loops) {
-                $this->loops[0]->setAttribute('with_loop', true);
-            }
-
             array_unshift($this->loops, $node);
-        } elseif ($this->loops && $node instanceof Twig_Node_Expression_Name && 'loop' === $node->getAttribute('name')) {
-            $this->loops[0]->setAttribute('with_loop', true);
-        } elseif ($this->loops && $node instanceof Twig_Node_Include && !$node->getAttribute('only')) {
-            $this->loops[0]->setAttribute('with_loop', true);
+        } elseif ($this->loops
+            // when do we need to add the loop variable back?
+            && (
+                // the loop variable is referenced here
+                ($node instanceof Twig_Node_Expression_Name && 'loop' === $node->getAttribute('name'))
+                ||
+                // include without the only attribute
+                ($this->loops && $node instanceof Twig_Node_Include && !$node->getAttribute('only'))
+            )
+        ) {
+            foreach ($this->loops as $loop) {
+                $loop->setAttribute('with_loop', true);
+            }
         }
     }
 
diff --git a/test/Twig/Tests/NodeVisitor/OptimizerTest.php b/test/Twig/Tests/NodeVisitor/OptimizerTest.php
index b3a9a6f..1501b57 100644
--- a/test/Twig/Tests/NodeVisitor/OptimizerTest.php
+++ b/test/Twig/Tests/NodeVisitor/OptimizerTest.php
@@ -29,11 +29,23 @@ class Twig_Tests_NodeVisitor_OptimizerTest extends PHPUnit_Framework_TestCase
     {
         return array(
             array('{% for i in foo %}{% endfor %}', array('i' => false)),
+
             array('{% for i in foo %}{{ loop.index }}{% endfor %}', array('i' => true)),
-            array('{% for i in foo %}{% for j in foo %}{% endfor %}{% endfor %}', array('i' => true, 'j' => false)),
+
+            array('{% for i in foo %}{% for j in foo %}{% endfor %}{% endfor %}', array('i' => false, 'j' => false)),
+
             array('{% for i in foo %}{% include "foo" %}{% endfor %}', array('i' => true)),
+
             array('{% for i in foo %}{% include "foo" only %}{% endfor %}', array('i' => false)),
+
+            // "i" should be false
             array('{% for i in foo %}{% for j in foo %}{{ loop.index }}{% endfor %}{% endfor %}', array('i' => true, 'j' => true)),
+
+            array('{% for i in foo %}{% for j in foo %}{{ loop.parent.loop.index }}{% endfor %}{% endfor %}', array('i' => true, 'j' => true)),
+
+            //array('{% for i in foo %}{% for j in foo %}{{ foo.parent.loop.index }}{% endfor %}{% endfor %}', array('i' => false, 'j' => false)),
+
+            array('{% for i in foo %}{% for j in foo %}{{ loop["parent"].loop.index }}{% endfor %}{% endfor %}', array('i' => true, 'j' => true)),
         );
     }
 
-- 
1.7.2.5