Prevent importing or calling reserved macro names

This also fixes the logic detecting reserved macro names to account for
the fact that they are compiled prefixed with get() since a very long
time and the logic preventing conflicts was broken.

lib/Twig/ExpressionParser.php

@@ -387,7 +387,13 @@ class Twig_ExpressionParser
                     throw new Twig_Error_Syntax(sprintf('Dynamic macro names are not supported (called on "%s")', $node->getAttribute('name')), $token->getLine(), $this->parser->getFilename());
                 }
 
-                $node = new Twig_Node_Expression_MethodCall($node, 'get'.$arg->getAttribute('value'), $arguments, $lineno);
+                $name = $arg->getAttribute('value');
+
+                if ($this->parser->isReservedMacroName($name)) {
+                    throw new Twig_Error_Syntax(sprintf('"%s" cannot be called as macro as it is a reserved keyword', $name), $token->getLine(), $this->parser->getFilename());
+                }
+
+                $node = new Twig_Node_Expression_MethodCall($node, 'get'.$name, $arguments, $lineno);
                 $node->setAttribute('safe', true);
 
                 return $node;

lib/Twig/Parser.php

@@ -254,21 +254,30 @@ class Twig_Parser implements Twig_ParserInterface
 
     public function setMacro($name, Twig_Node_Macro $node)
     {
-        if (null === $this->reservedMacroNames) {
-            $this->reservedMacroNames = array();
-            $r = new ReflectionClass($this->env->getBaseTemplateClass());
-            foreach ($r->getMethods() as $method) {
-                $this->reservedMacroNames[] = $method->getName();
-            }
-        }
-
-        if (in_array($name, $this->reservedMacroNames)) {
+        if ($this->isReservedMacroName($name)) {
             throw new Twig_Error_Syntax(sprintf('"%s" cannot be used as a macro name as it is a reserved keyword', $name), $node->getLine(), $this->getFilename());
         }
 
         $this->macros[$name] = $node;
     }
 
+    public function isReservedMacroName($name)
+    {
+        if (null === $this->reservedMacroNames) {
+            $this->reservedMacroNames = array();
+            $r = new ReflectionClass($this->env->getBaseTemplateClass());
+            foreach ($r->getMethods() as $method) {
+                $methodName = strtolower($method->getName());
+
+                if ('get' === substr($methodName, 0, 3) && isset($methodName[3])) {
+                    $this->reservedMacroNames[] = substr($methodName, 3);
+                }
+            }
+        }
+
+        return in_array(strtolower($name), $this->reservedMacroNames);
+    }
+
     public function addTrait($trait)
     {
         $this->traits[] = $trait;

lib/Twig/TokenParser/From.php

@@ -52,6 +52,10 @@ class Twig_TokenParser_From extends Twig_TokenParser
         $node = new Twig_Node_Import($macro, new Twig_Node_Expression_AssignName($this->parser->getVarName(), $token->getLine()), $token->getLine(), $this->getTag());
 
         foreach ($targets as $name => $alias) {
+            if ($this->parser->isReservedMacroName($name)) {
+                throw new Twig_Error_Syntax(sprintf('"%s" cannot be an imported macro as it is a reserved keyword', $name), $token->getLine(), $stream->getFilename());
+            }
+
             $this->parser->addImportedSymbol('function', $alias, 'get'.$name, $node->getNode('var'));
         }
 

test/Twig/Tests/Fixtures/tags/macro/from_with_reserved_name.test

@@ -0,0 +1,9 @@
+--TEST--
+"from" tag with reserved name
+--TEMPLATE--
+{% from 'forms.twig' import templateName %}
+--TEMPLATE(forms.twig)--
+--DATA--
+return array()
+--EXCEPTION--
+Twig_Error_Syntax: "templateName" cannot be an imported macro as it is a reserved keyword in "index.twig" at line 2

test/Twig/Tests/Fixtures/tags/macro/import_with_reserved_nam.test

@@ -0,0 +1,11 @@
+--TEST--
+"from" tag with reserved name
+--TEMPLATE--
+{% import 'forms.twig' as macros %}
+
+{{ macros.parent() }}
+--TEMPLATE(forms.twig)--
+--DATA--
+return array()
+--EXCEPTION--
+Twig_Error_Syntax: "parent" cannot be called as macro as it is a reserved keyword in "index.twig" at line 4

test/Twig/Tests/Fixtures/tags/macro/reserved_name.test

@@ -0,0 +1,10 @@
+--TEST--
+"macro" tag with reserved name
+--TEMPLATE--
+{% macro parent(arg1, arg2) %}
+    parent
+{% endmacro %}
+--DATA--
+return array()
+--EXCEPTION--
+Twig_Error_Syntax: "parent" cannot be used as a macro name as it is a reserved keyword in "index.twig" at line 2

test/Twig/Tests/ParserTest.php

@@ -16,7 +16,7 @@ class Twig_Tests_ParserTest extends PHPUnit_Framework_TestCase
     public function testSetMacroThrowsExceptionOnReservedMethods()
     {
         $parser = $this->getParser();
-        $parser->setMacro('display', $this->getMock('Twig_Node_Macro', array(), array(), '', null));
+        $parser->setMacro('parent', $this->getMock('Twig_Node_Macro', array(), array(), '', null));
     }
 
     /**