bug#39563: temp files

[Pedro Moreira <pedro.moreira@ipbeja.pt>]

Hello!

if a user edits a php file using emacs directly at the webserver, emacs 
automatically saves a temp file at the same location, for example the 
user opens index.php, emacs stores a copy index.php~.

Therefore the code in that file is exposed. If an attacker tries to 
access files like https://domain.com/index.php~ the server wont 
interpret that file as php and presents it as plain text exposing the 
source code.

I know this could be resolved with webserver configuration. But it is a 
problem i just discovered and leaves me very unconfortable using emacs.

Maybe should be better the temp file beying stored like index~.php or 
index.bck.php.

Thanks