bug#28807: 25.2; dired-actual-switches` and .dir-locals.el

[leo]

> On 13 Oct 2017, at 20:09, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> From: leo <dev@halloleo.hailmail.net>
>> Date: Fri, 13 Oct 2017 19:16:08 +1100
>> 
>>    ;;; Directory Local Variables
>>    ;;; For more information see (info "(emacs) Directory Variables")
>> 
>>    ((dired-mode .
>>      ((dired-actual-switches . "-laht")
>>       (subdirs . nil))))
>> 
>> * Create a subirectory `subdir` inside `mydir`
>> * Create some files with different timestamp and different names in there.
>> 
>> Bug 1: .dir-locals.el not applied the first time
>> ================================================
>> 
>> * Launch `emacs -Q`
>> * Open `mydir` via `M-x find-file` as a dired buffer
>> * Observe that `mydir` is **not** in date order sorted
>> * Kill `mydir` buffer.
>> * Open again `mydir` via `M-x find-file` as a dired buffer
>> * Observe that `mydir` **is**  in date order sorted (as it should be)
>> 
>> Bug 2: (subdirs . nil) rule not obeyed
>> ======================================
>> 
>> * Stay in that `emacs -Q` session
>> * Kill `mydir` buffer.
>> * Open `mydir/subdir` via `M-x find-file` as a dired buffer
>> * Observe that `mydir` **is**  in date order sorted (as it **not** should be)
> 
> I think this is because both settings take their effect before the
> Dired mode is turned on in the buffer.  IOW, these customizations
> simply cannot have the desired effect, as they are conditioned on
> the wrong condition.

Mmmh, the dired-actual-switches variable *did* work with the dired-x package 
(when using its own .dired files) - but the newest dired-x manual states that 
the .dired mechanism is depreciated over the .dir-locals.el system. However as 
tested the .dir-locals.el mechanism does not work.