MFH: fix bug #40836 (Segfault in ext/dom)

add test

ext/dom/node.c

@@ -1012,7 +1012,7 @@ PHP_FUNCTION(dom_node_insert_before)
 			new_child = xmlAddPrevSibling(refp, child);
 		}
 	} else {
-		if (child->parent == parentp){
+		if (child->parent != NULL){
 			xmlUnlinkNode(child);
 		}
 		if (child->type == XML_TEXT_NODE && parentp->last != NULL && parentp->last->type == XML_TEXT_NODE) {

ext/dom/tests/bug40836.phpt

@@ -0,0 +1,29 @@
+--TEST--
+Bug # 40836 (Segfault in insertBefore)
+--SKIPIF--
+<?php require_once('skipif.inc'); ?>
+--FILE--
+<?php
+$dom = new DOMDocument("1.0", "UTF-8");
+$dom->preserveWhiteSpace = false;
+$xml = (binary)'<?xml version="1.0" encoding="utf-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom">
+  <entry xmlns="http://www.w3.org/2005/Atom">
+    <updated>2007-02-14T00:00:00+01:00</updated>
+    <content>
+      <div xmlns="http://www.w3.org/1999/xhtml">
+        <p>paragraph</p>
+      </div>
+    </content>
+  </entry>
+</feed>';
+$dom->loadXML($xml);
+$entry = $dom->getElementsByTagNameNS("http://www.w3.org/2005/Atom", "entry")->item(0);
+$contentNode = $entry->getElementsByTagName("content")->item(0)->firstChild;
+$dateNode = $entry->getElementsByTagName("updated")->item(0)->firstChild;
+$contentNode->firstChild->insertBefore($dateNode);
+echo $dom->saveXML();
+?>
+--EXPECT--
+<?xml version="1.0" encoding="utf-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom"><entry xmlns="http://www.w3.org/2005/Atom"><updated/><content><div xmlns="http://www.w3.org/1999/xhtml"><p>paragraph2007-02-14T00:00:00+01:00</p></div></content></entry></feed>