fixed the join filter when several items have the same key

lib/Twig/Extension/Core.php

@@ -489,7 +489,7 @@ function twig_array_merge($arr1, $arr2)
 function twig_join_filter($value, $glue = '')
 {
     if ($value instanceof Traversable) {
-        $value = iterator_to_array($value);
+        $value = iterator_to_array($value, false);
     }
 
     return implode($glue, (array) $value);

test/Twig/Tests/integrationTest.php

@@ -114,20 +114,18 @@ function test_foo($value = 'foo')
     return $value;
 }
 
-class Foo implements IteratorAggregate
+class Foo implements Iterator
 {
     const BAR_NAME = 'bar';
 
+    public $position = 0;
+    public $array = array(1, 2);
+
     public function bar($param1 = null, $param2 = null)
     {
         return 'bar'.($param1 ? '_'.$param1 : '').($param2 ? '-'.$param2 : '');
     }
 
-    public function getIterator()
-    {
-        return new ArrayObject(array(1, 2));
-    }
-
     public function getFoo()
     {
         return 'foo';
@@ -157,6 +155,31 @@ class Foo implements IteratorAggregate
     {
         return strtolower($value);
     }
+
+    public function rewind()
+    {
+        $this->position = 0;
+    }
+
+    public function current()
+    {
+        return $this->array[$this->position];
+    }
+
+    public function key()
+    {
+        return 'a';
+    }
+
+    public function next()
+    {
+        ++$this->position;
+    }
+
+    public function valid()
+    {
+        return isset($this->array[$this->position]);
+    }
 }
 
 class TestTokenParser_☃ extends Twig_TokenParser