bug#52004: dired-rename-subdir-2: Expected to find ‘/tmp/a/./’ in headerline of /tmp/a/

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

>> $ mkdir /tmp/a /tmp/b
>> $ emacs -Q /tmp/a
>> Put the cursor on the "." line, and hit R and try and move it to /tmp/b .
>> Overwrite ‘/tmp/b’? [Type yn!q or C-h] y
>> dired-rename-subdir-2: Expected to find ‘/tmp/a/./’ in headerline of /tmp/a/

I've now made it refuse to rename . and .. -- doing so is just too
confusing even if it worked.