fixed the "filter" filter when the argument is \Traversable but does not implement \Iterator

CHANGELOG

@@ -1,5 +1,6 @@
 * 1.42.0 (2019-XX-XX)
 
+ * fixed the "filter" filter when the argument is \Traversable but does not implement \Iterator (\SimpleXmlElement for instance)
  * fixed a PHP fatal error when calling a macro imported in a block in a nested block
  * fixed a PHP fatal error when calling a macro imported in the template in another macro
  * fixed wrong error message on "import" and "from"

src/Extension/CoreExtension.php

@@ -1686,21 +1686,30 @@ function twig_array_batch($items, $size, $fill = null, $preserveKeys = true)
     return $result;
 }
 
-function twig_array_filter($array, $arrow)
-{
-    if (\is_array($array)) {
-        if (\PHP_VERSION_ID >= 50600) {
-            return array_filter($array, $arrow, \ARRAY_FILTER_USE_BOTH);
+if (\PHP_VERSION_ID < 50500) {
+    function twig_array_filter($array, $arrow)
+    {
+        if (\is_array($array)) {
+            if (\PHP_VERSION_ID >= 50600) {
+                return array_filter($array, $arrow, \ARRAY_FILTER_USE_BOTH);
+            }
+
+            return array_filter($array, $arrow);
         }
 
-        return array_filter($array, $arrow);
-    }
+        while ($array instanceof \IteratorAggregate) {
+            $array = $array->getIterator();
+        }
 
-    while ($array instanceof \IteratorAggregate) {
-        $array = $array->getIterator();
-    }
+        // some internal PHP classes are \Traversable but do not implement \Iterator
+        if ($array instanceof \Iterator) {
+            return new \CallbackFilterIterator($array, $arrow);
+        }
 
-    return new \CallbackFilterIterator($array, $arrow);
+        throw new RuntimeException('The "filter" filter argument only supports objects implementing \Iterator; upgrade to PHP 5.5+.');
+    }
+} else {
+    require_once __DIR__.'/twig_array_filter_55.php';
 }
 
 function twig_array_map($array, $arrow)

src/Extension/twig_array_filter_55.php

@@ -0,0 +1,10 @@
+<?php
+
+function twig_array_filter($array, $arrow)
+{
+    foreach ($array as $k => $v) {
+        if ($arrow($v, $k)) {
+            yield $k => $v;
+        }
+    }
+}

test/Twig/Tests/Fixtures/filters/filter_php_55.test

@@ -0,0 +1,23 @@
+--TEST--
+"filter" filter (PHP 5.5 required)
+--CONDITION--
+version_compare(phpversion(), '5.5.0', '>=')
+--TEMPLATE--
+{% for k, v in xml|filter(x => true) %}
+{{ k }}/{{ v }}
+{% endfor %}
+
+{# we can iterate more than once #}
+{% for k, v in xml|filter(x => true) %}
+{{ k }}/{{ v }}
+{% endfor %}
+--DATA--
+return ['xml' => new \SimpleXMLElement('<?xml version="1.0" encoding="UTF-8"?><doc><elem>foo</elem><elem>bar</elem><elem>baz</elem></doc>')]
+--EXPECT--
+elem/foo
+elem/bar
+elem/baz
+
+elem/foo
+elem/bar
+elem/baz

test/Twig/Tests/Fixtures/filters/filter_php_56.test

@@ -9,6 +9,11 @@ version_compare(phpversion(), '5.6.0', '>=')
     {{ k }} = {{ v }}
 {% endfor %}
 
+{% for k, v in it|filter((v, k) => (v > offset) and (k != "d")) -%}
+    {{ k }} = {{ v }}
+{% endfor %}
+
+{# we can iterate more than once #}
 {% for k, v in it|filter((v, k) => (v > offset) and (k != "d")) -%}
     {{ k }} = {{ v }}
 {% endfor %}
@@ -18,3 +23,5 @@ return ['it' => new \ArrayIterator(['a' => 1, 'b' => 2, 'c' => 5, 'd' => 8])]
 c = 5
 
 c = 5
+
+c = 5