[Pkg-roundcube-maintainers] Bug#964599: Roundcube-core Overwrites Local Changes in _styles.less

[Bryan Walton (Debian)]

Package: roundcube-core
Version: 1.4.7+dfsg.1-1~bpo10+1

_styles.less, located in /usr/share/roundcube/skins/elastic/styles, is a 
file that exists for local customizations of the roundcube templates.  
The file, as shipped by Debian has one line in it, that reads:

/* Here you can put your custom styles that will be appended to the 
output css file */

However, any customization placed in that file is overwritten upon the 
next update.  Apt doesn't ask whether I want to keep the changes or use 
the new one -- it simply overwrites my local changes.

I suggest that apt prompt the user how to proceed with this file.  If 
there are local changes, then the system should run (or remind the user 
that they will need to run): lessc -x styles.less > styles.css to import 
their local customization back into the styles.css after the update.

I am using Debian 10.4, kernel 4.19.0-9-amd64, and libc6 2.28-10.