bug#49043: 27.1: ibuffer-toggle-filter-group [BUGFIX]

[Stephen Berman]

On Sat, 19 Jun 2021 17:56:24 +0200 Michael Albinus <michael.albinus@gmx.de> 
wrote:

> Stephen Berman <stephen.berman@gmx.net> writes:
>
> Hi Steve,
>
>> I do.  It's the result of an error being raised in Tramp.  Here's the
>> recipe (reliably reproducible on
>>
>> GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.29,
>> cairo version 1.17.4) of 2021-06-06 built on strobelfs 
>> Repository revision: 218d2d1509673d8bc67014558a31f5d0da1be5c6
>> Repository branch: master
>> Windowing system distributor 'The X.Org Foundation', version 11.0.12011000
>> Configured using: 'configure --with-native-compilation 'CFLAGS=-Og -g3''
>> Configured features: ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS
>> GSETTINGS HARFBUZZ JPEG LCMS2 LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP
>> NOTIFY INOTIFY PDUMPER PNG RSVG SECCOMP SOUND THREADS TIFF
>> TOOLKIT_SCROLL_BARS X11 XDBE XIM XPM GTK3 ZLIB
>> ):
>>
>> 0. emacs -Q
>> 1. Create a nonempty ZIP file test.zip (content is irrelevant).
>> 2. Visit the directory containing test.zip in Dired.
>> 3. Type `M-x load-library RET dired-x RET'.
>> 4. With point on the Dired line containing test.zip type `M-!', which
>>    prompts with "! on test.zip {3 guesses} [unzip]:" and type RET to
>>    execute unzip (this of course requires having the unzip program).
>> 5. With point still on the test.zip line type `D' and at the prompt `y'
>>    to delete the ZIP file.
>> => This raises a file-error (see below), but the ZIP file is deleted.
>> 6. Type `M-x ibuffer'.
>> => This raises the error "tramp-error: Method ‘archive’ is not known."
>> 7. In the *Ibuffer* buffer type `g'.
>> => This raises the error "ibuffer-current-state-list: Args out of range:
>>    #<buffer *Ibuffer*>, 280, 332". 
>
> Thanks for this. Apparently, it is the same error as bug#49030, I'll
> merge both. A fix will follow soon, pls check whether it works for you.

I rebuilt with your patch, and confirm it fixes the error in step 5
above, and hence the subsequent errors do not occur.  Thanks!

Since essentially my recipe was previously reported in bug#49030, I
think that bug can be closed.  But before closing bug#49043, perhaps
Boruch Baum should chime in, since he only reported the problem in
Ibuffer.  I showed this can be triggered by the Tramp bug, but perhaps
there are other triggers too, and if so some additional safeguard in
Ibuffer such as what Lars suggested may be appropriate.

Steve Berman