bug#23033: 24.5; Lock file uses the same extension as the file it's locking

[Michael Sloan]

On Fri, Nov 8, 2019 at 6:10 AM Stefan Kangas <stefan@marxist.se> wrote:

(The most clear would be a suffix "-emacs-lock" or "-lock" but that is
probably too ugly and long.)

Appending `.lock` seems fine to me (note the period rather than hyphen).  I don't find it ugly, instead explanatory!  If users do see these file names, then it is clearer that they are lock files.  There is precedent for use of this file extension[0], and there's also lots of precedent for stacking file extensions.

I propose keeping the traditional `.#` prefix but adding a `.lock` suffix.

[0]: https://fileinfo.com/extension/lock