Add regression test for GH-11682

This bug was already fixed via 15ff830, but we really need more
test coverage.

Co-authored-by: Arne Blankerts <[email protected]>

Author: ndossche

ext/dom/tests/gh11682.phpt

@@ -0,0 +1,27 @@
+--TEST--
+Fix GH-11682 (Consecutive calls to DOMNode::before and DOMNode::remove unlink wrong nodes)
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+
+$dom = new DOMDocument;
+$dom->loadXML('<?xml version="1.0" ?><root><node /></root>');
+
+$list = [
+    $dom->createElement('foo1'),
+    $dom->createElement('foo2'),
+    $dom->createElement('foo3')
+];
+
+$node = $dom->getElementsByTagName('node')->item(0);
+
+$node->before(...$list);
+$node->remove();
+
+echo $dom->saveXML();
+
+?>
+--EXPECT--
+<?xml version="1.0"?>
+<root><foo1/><foo2/><foo3/></root>