From 508a2411799ef9a7fca928aa8edac322b4f115b9 Mon Sep 17 00:00:00 2001
From: Fabien Potencier <fabien.potencier@gmail.com>
Date: Sun, 19 Dec 2010 22:24:10 +0100
Subject: [PATCH] forced functions to have fn_ as a prefix to avoid name clashes between functions and variables

---
 doc/advanced.rst                                   |   10 ++++++++--
 lib/Twig/Node/Expression/Function.php              |    3 +++
 lib/Twig/Node/From.php                             |    2 +-
 test/Twig/Tests/Fixtures/expressions/function.test |    4 ++--
 test/Twig/Tests/Fixtures/globals.test              |    4 ++--
 5 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/doc/advanced.rst b/doc/advanced.rst
index 97a5618..9634b1b 100644
--- a/doc/advanced.rst
+++ b/doc/advanced.rst
@@ -115,11 +115,14 @@ A function is a variable that is callable. The value is an instance of
 ``Twig_Function``::
 
     $twig = new Twig_Environment($loader);
-    $twig->addGlobal('lipsum', new Twig_Function(new Text(), 'getLipsum'));
+    $twig->addGlobal('fn_lipsum', new Twig_Function(new Text(), 'getLipsum'));
 
     // or
     $twig->addGlobal('text', new Text());
-    $twig->addGlobal('lipsum', new Twig_Function('text', 'getLipsum'));
+    $twig->addGlobal('fn_lipsum', new Twig_Function('text', 'getLipsum'));
+
+To avoid name clashes with variables, function names must be prefixed with
+``fn_`` when defined (the prefix must not be added in templates).
 
 The first argument to ``Twig_Function`` is an object or a variable name
 referencing an object.
@@ -128,6 +131,9 @@ You can then use the ``lipsum`` function anywhere in a template:
 
 .. code-block:: jinja
 
+    {# A lipsum variable does not override the lipsum function #}
+    {% set lipsum = 'foo' %}
+
     {{ lipsum(40) }}
 
 .. note::
diff --git a/lib/Twig/Node/Expression/Function.php b/lib/Twig/Node/Expression/Function.php
index 0cf5e95..6b5c131 100644
--- a/lib/Twig/Node/Expression/Function.php
+++ b/lib/Twig/Node/Expression/Function.php
@@ -17,6 +17,9 @@ class Twig_Node_Expression_Function extends Twig_Node_Expression
 
     public function compile($compiler)
     {
+        // functions must be prefixed with fn_
+        $this->getNode('name')->setAttribute('name', 'fn_'.$this->getNode('name')->getAttribute('name'));
+
         $compiler
             ->raw('$this->callFunction($context, ')
             ->subcompile($this->getNode('name'))
diff --git a/lib/Twig/Node/From.php b/lib/Twig/Node/From.php
index a71a7e2..f75392a 100644
--- a/lib/Twig/Node/From.php
+++ b/lib/Twig/Node/From.php
@@ -36,7 +36,7 @@ class Twig_Node_From extends Twig_Node_Import
         foreach ($this->getAttribute('imports') as $name => $alias) {
             $compiler
                 ->write('$context[')
-                ->repr($alias)
+                ->repr('fn_'.$alias)
                 ->raw('] = new Twig_Function(')
                 ->subcompile($this->getNode('var'))
                 ->raw(', ')
diff --git a/test/Twig/Tests/Fixtures/expressions/function.test b/test/Twig/Tests/Fixtures/expressions/function.test
index 90409ad..4175f9c 100644
--- a/test/Twig/Tests/Fixtures/expressions/function.test
+++ b/test/Twig/Tests/Fixtures/expressions/function.test
@@ -6,8 +6,8 @@ Twig supports calling variables
 --DATA--
 return array(
     'foo' => new Foo(),
-    'lower' => new Twig_Function('foo', 'strToLower'),
-    'lower1' => new Twig_Function(new Foo(), 'strToLower'))
+    'fn_lower' => new Twig_Function('foo', 'strToLower'),
+    'fn_lower1' => new Twig_Function(new Foo(), 'strToLower'))
 --EXPECT--
 foo
 foo
diff --git a/test/Twig/Tests/Fixtures/globals.test b/test/Twig/Tests/Fixtures/globals.test
index 02d577c..e816ca6 100644
--- a/test/Twig/Tests/Fixtures/globals.test
+++ b/test/Twig/Tests/Fixtures/globals.test
@@ -14,8 +14,8 @@ global variables
 {{ foo() }}
 
 --DATA--
-$twig->addGlobal('foo', new Twig_Function(new Foo(), 'getFoo'));
-$twig->addGlobal('bar', new Twig_Function('barObj', 'getFoo'));
+$twig->addGlobal('fn_foo', new Twig_Function(new Foo(), 'getFoo'));
+$twig->addGlobal('fn_bar', new Twig_Function('barObj', 'getFoo'));
 return array('barObj' => new Foo());
 --EXPECT--
 foo
-- 
1.7.2.5