Issue #2511306 by ElusiveMind, JeroenT, leolando.tan, cilefen, charginghawk:...

Issue #2511306 by ElusiveMind, JeroenT, leolando.tan, cilefen, charginghawk: Error: Call to a member function getElementsByTagName() in filter.module when filter_dom_serialize() is passed an empty document.

modules/filter/filter.module

@@ -1119,18 +1119,23 @@ function filter_dom_serialize($dom_document) {
   $body_node = $dom_document->getElementsByTagName('body')->item(0);
   $body_content = '';
 
-  foreach ($body_node->getElementsByTagName('script') as $node) {
-    filter_dom_serialize_escape_cdata_element($dom_document, $node);
-  }
+  if ($body_node !== NULL) {
+    foreach ($body_node->getElementsByTagName('script') as $node) {
+      filter_dom_serialize_escape_cdata_element($dom_document, $node);
+    }
 
-  foreach ($body_node->getElementsByTagName('style') as $node) {
-    filter_dom_serialize_escape_cdata_element($dom_document, $node, '/*', '*/');
-  }
+    foreach ($body_node->getElementsByTagName('style') as $node) {
+      filter_dom_serialize_escape_cdata_element($dom_document, $node, '/*', '*/');
+    }
 
-  foreach ($body_node->childNodes as $child_node) {
-    $body_content .= $dom_document->saveXML($child_node);
+    foreach ($body_node->childNodes as $child_node) {
+      $body_content .= $dom_document->saveXML($child_node);
+    }
+    return preg_replace('|<([^> ]*)/>|i', '<$1 />', $body_content);
+  }
+  else {
+    return $body_content;
   }
-  return preg_replace('|<([^> ]*)/>|i', '<$1 />', $body_content);
 }
 
 /**

modules/filter/filter.test

@@ -1983,3 +1983,26 @@ class FilterSettingsTestCase extends DrupalWebTestCase {
     }
   }
 }
+
+/**
+ * Tests DOMDocument serialization.
+ */
+class FilterDOMSerializeTestCase extends DrupalWebTestCase {
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Serialization',
+      'description' => 'Test serialization of DOMDocument objects.',
+      'group' => 'Filter',
+    );
+  }
+
+  /**
+   * Tests empty DOMDocument object.
+   */
+  function testFilterEmptyDOMSerialization() {
+    $document = new DOMDocument();
+    $result = filter_dom_serialize($document);
+    $this->assertEqual('', $result);
+  }
+}