bug#16533: 24.3.50; "s" no longer works as documented in dired

bug#16533: 24.3.50; "s" no longer works as documented in dired

[Markus Triska]

When I do:

   $ emacs -Q

and then view my home directory in dired with:

   C-x C-f RET

and then list all files in decreasing order of their file sizes with:

   C-u s S RET

(making the switches read: "-alS")

and then press "s", dired says "Dired by date" but still orders by size.

This works as expected in Emacs 22.1.1, where "s" then sorts by date.


In GNU Emacs 24.3.50.2 (x86_64-apple-darwin10.8.0, X toolkit, Xaw3d scroll bars)
 of 2014-01-04 on mt-imac.local
Windowing system distributor `The X.Org Foundation', version 11.0.11404000
Configured using:
 `configure CFLAGS=-I/opt/local/include LDFLAGS=-L/opt/local/lib'

bug#16533: 24.3.50; "s" no longer works as documented in dired

[Glenn Morris]

Markus Triska wrote:

> When I do:
>
>    $ emacs -Q
>
> and then view my home directory in dired with:
>
>    C-x C-f RET
>
> and then list all files in decreasing order of their file sizes with:
>
>    C-u s S RET
>
> (making the switches read: "-alS")
>
> and then press "s", dired says "Dired by date" but still orders by size.

So is the complaint that it says "Dired by date"?
I can't reproduce this.

> This works as expected in Emacs 22.1.1, where "s" then sorts by date.

I don't understand. "-alS" means ls should sort by size.
Sort by date would be "-alt".

> In GNU Emacs 24.3.50.2 (x86_64-apple-darwin10.8.0, X toolkit, Xaw3d scroll bars)
>  of 2014-01-04 on mt-imac.local

bug#16533: 24.3.50; "s" no longer works as documented in dired

[Glenn Morris]

Glenn Morris wrote:

>> This works as expected in Emacs 22.1.1, where "s" then sorts by date.
>
> I don't understand.

Oh, I see. Works for me.

What is the value of dired-use-ls-dired?

bug#16533: 24.3.50; "s" no longer works as documented in dired

[Markus Triska]

Glenn Morris <rgm@gnu.org> writes:

> What is the value of dired-use-ls-dired?

Its value is nil. When I start dired after "$ emacs -Q", it displays:

  ls does not support --dired; see `dired-use-ls-dired' for more details.

Following the instructions in the documentation of `dired-use-ls-dired',
I tried Emacs's own emulation of "ls" by evaluating (in "$ emacs -Q"):

  (setq ls-lisp-use-insert-directory-program nil)
  (require 'ls-lisp)

The original problem shows up with this emulation as well.

bug#16533: 24.3.50; "s" no longer works as documented in dired

[Glenn Morris]

Markus Triska wrote:

> The original problem shows up with this emulation as well.

Not for me.

Please confirm what the problem actually is - just that it says "by
date" in the mode line?

When it does so, what are the values of

dired-ls-sorting-switches
dired-sort-by-date-regexp
dired-actual-switches

bug#16533: 24.3.50; "s" no longer works as documented in dired

[Eli Zaretskii]

> From: Markus Triska <markus.triska@gmx.at>
> Date: Fri, 24 Jan 2014 18:23:43 +0100
> Cc: 16533@debbugs.gnu.org
> 
> Glenn Morris <rgm@gnu.org> writes:
> 
> > What is the value of dired-use-ls-dired?
> 
> Its value is nil. When I start dired after "$ emacs -Q", it displays:
> 
>   ls does not support --dired; see `dired-use-ls-dired' for more details.
> 
> Following the instructions in the documentation of `dired-use-ls-dired',
> I tried Emacs's own emulation of "ls" by evaluating (in "$ emacs -Q"):
> 
>   (setq ls-lisp-use-insert-directory-program nil)
>   (require 'ls-lisp)
> 
> The original problem shows up with this emulation as well.

Aren't you using ls-lisp emulation by default?  What does the
following produce in "emacs -Q"?

  M-: (featurep 'ls-lisp) RET

bug#16533: 24.3.50; "s" no longer works as documented in dired

[Eli Zaretskii]

> From: Glenn Morris <rgm@gnu.org>
> Date: Fri, 24 Jan 2014 13:32:55 -0500
> Cc: 16533@debbugs.gnu.org
> 
> Please confirm what the problem actually is - just that it says "by
> date" in the mode line?

I think the problem is that is says "by date", but the actual sorting
is not changed, i.e. it stays by size in this case.

> When it does so, what are the values of
> 
> dired-ls-sorting-switches

"SXU"

> dired-sort-by-date-regexp

"\\(\\`\\| \\)-[^- ]*t[^ SXU]*\\(\\(\\`\\| +\\)\\(--[^ ]+\\|-[^- tSXU]+\\)\\)* *$"

> dired-actual-switches

"-alSt"

And the latter is the root cause of the problem, IMO: the -S switch is
not removed from dired-actual-switches.

The problem here seems to be that dired-sort-toggle blindly adds the
"-t" flag to dired-actual-switches, although in this case the sorting
is not by date at all.  I don't understand the logic here; it seems
like dired-sort-toggle assumes without testing that the directory is
sorted either by date or by name, which is of course false.

Is it a portable assumption that the last switch that determines the
sorting order overrides all the previous ones?  If so, ls-lisp.el
should be fixed to implement that requirement.  But if not, we need to
fix dired.el not to put more than one sorting option into
dired-actual-switches.  In particular, the logic in dired-sort-toggle
seems to be flawed.

bug#16533: 24.3.50; "s" no longer works as documented in dired

[Glenn Morris]

Eli Zaretskii wrote:

> The problem here seems to be that dired-sort-toggle blindly adds the
> "-t" flag to dired-actual-switches, although in this case the sorting
> is not by date at all.  I don't understand the logic here; it seems
> like dired-sort-toggle assumes without testing that the directory is
> sorted either by date or by name, which is of course false.
>
> Is it a portable assumption that the last switch that determines the
> sorting order overrides all the previous ones?  If so, ls-lisp.el
> should be fixed to implement that requirement.  But if not, we need to
> fix dired.el not to put more than one sorting option into
> dired-actual-switches.  In particular, the logic in dired-sort-toggle
> seems to be flawed.

Duh, I seem to have been very thick here, since the original report
seems clear now. I guess I missed the 'then press "s"'.

I guess it is not a portable assumption, since presumably whatever
crappy ls Mac OS X uses does not work that way.

Prior to r101356, dired-sort-toggle removed dired-ls-sorting-switches.
Now it seems not to. That change was made to fix another bug,
http://debbugs.gnu.org/6987