bug#66663: 30.0.50; Allow dir locals file selection in *-dir-local-variable functions

[Mauro Aranda <maurooaranda@gmail.com>]

On 21/10/23 09:45, Eli Zaretskii wrote:
 >> Cc: Juri Linkov <juri@linkov.net>
 >> Date: Sat, 21 Oct 2023 09:16:28 -0300
 >> From: Mauro Aranda <maurooaranda@gmail.com>
 >>
 >> +Since both @file{.dir-locals.el} and @file{.dir-locals-2.el} file
 >> +might exist in the same directory, there may be some clash about which
 >> +file you want to modify when executing the above three commands.  To
 >> +solve that, all three of them take a prefix argument, to indicate
 >> +which file you want to modify.  When both files exist, a prefix
 >> +argument means to prefer to modify @file{.dir-locals.el} instead of
 >> +@file{.dir-locals-2.el}.  When one of the files doesn't exist, and
 >> +you're adding a variable or copying the file-local variables, a prefix
 >> +argument means to modify (i.e., create) the file that doesn't yet
 >> +exist.
 >
 > I think a better UI is to ask the user when the command is invoked
 > with a prefix argument.

Yes, that makes sense.  I'll try that approach.