Steps to reproduce
Do CVS checkout of 19-STABLE
Go to admin/index.php to process the upgrade.
What I expected to happen
Upgrade confirmation page should be displayed
What actually happened
Following error was produced by Opera 9.00/Linux
XML parsing failed: syntax error
Similar error message displayed by Firefox 126.96.36.199
Looking at the HTML, the source code of the page end with Yes/No form:
<form action="index.php" method="post"><div><input type="submit" value="Ne" /></div></form></div></div></div>
but there should be something like "</body></html>" to fit XHTML Strict.