run-perltidy deletes .bak files

[Alex-Jordan]

I was working on a macro file foo.pl and decided I wanted to start over with a different approach. I saved foo.pl as foo.pl.bak and got a fresh copy of foo.pl and make new edits. I got to a certain point and ran run-perltidy.pl on foo.pl. It turns out this destroyed foo.pl.bak.

I see now reading the documentation for run-perltidy.pl that it will do this, although I'm not sure the script considers if foo.pl.bak might already exist. Could we change it so the script aborts if foo.pl.bak exists, and it gives an error message? Then you could either decide to delete the backup file, or use a different extension.