1--TEST-- 2Bug #79451 (Using DOMDocument->replaceChild on doctype causes double free) 3--EXTENSIONS-- 4dom 5--FILE-- 6<?php 7$dom = new \DOMDocument(); 8$dom->loadHTML("<!DOCTYPE html><p>hello</p>"); 9$impl = new \DOMImplementation(); 10$dt = $impl->createDocumentType("html_replace", "", ""); 11$dom->replaceChild($dt, $dom->doctype); 12 13var_dump($dom->doctype->name); 14echo $dom->saveXML(); 15?> 16--EXPECTF-- 17string(12) "html_replace" 18<?xml version="1.0" standalone="yes"?> 19<!DOCTYPE html_replace> 20<html><body><p>hello</p></body></html> 21