The XEmacs compatibility alias `user-original-login-name' was declared
obsolete even in XEmacs:

https://bitbucket.org/xemacs/xemacs/src/e2ac728aa576a39ca5a7de608a1914dde5b1b083/lisp/obsolete.el#lines-461

Searching for its name on github gives 1383 code matches, most of which
seem to be copies of Emacs itself.

Are there any objections to marking it obsolete?

Best regards,
Stefan Kangas