minidom renameNode() drops an attribute renamed to a prefixed name #159637

Bug description:

Since gh-156665, Document.renameNode() raises NamespaceErr when it renames an attribute with no namespace to a prefixed name in a namespace, and the attribute has already been removed from its element when the error is raised.

from xml.dom.minidom import parseString
doc = parseString('<r a="1" b="2"/>')
attr = doc.documentElement.getAttributeNode('a')
try:
    doc.renameNode(attr, 'http://example.com/ns', 'p:a')
except Exception as e:
    print(type(e).__name__, e)
print(doc.documentElement.toxml())

NamespaceErr cannot use the prefix 'p' with an empty namespace
<r b="2"/>

Expected: the attribute is renamed to p:a in http://example.com/ns and stays on the element, as on 3.15.

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-159637: Fix renaming an attribute to a prefixed name in minidom #159638