bug#65843: 28.2; Too many iconified frames in .emacs.desktop -> crash (macOS)

[Christian Tanzer]

On 10.09.2023, at 05:20, Gerd Möllmann <gerd.moellmann@gmail.com> wrote:

On Sat, Sep 09, 2023 at 04:35:56PM -0000, Christian Tanzer via Bug reports for GNU Emacs, the Swiss army knife of text editors wrote:

=============================================================================

In Emacs 28 and Emacs 29, desktop-load crashes when there are too many

iconified frames in the .emacs.desktop file.

The two attached .emacs.desktop files show the smallest test case that

I could come up with:

- .emacs.desktop.works with 3 non-iconified and 4 iconified frames

 loads without problem in Emacs 28

 + desktop-load of this file crashes in Emacs 29.1

 + a .emacs.desktop with 3 non-iconified and 3 iconified frames works

   in Emacs 29.1

- .emacs.desktop.crashes with 3 non-iconified and 5 iconified frames

 leads to a crash in Emacs 28 (see attached problem report generated

 by macOS)

- I tried .emacs.desktop with up to 17 non-iconified frames in Emacs

 28 without problems

- Up to Emacs 27, I've never seen a problem with desktop-load crashing

=============================================================================

Alas, I cannot reproduce the abort here, with an unpatched master or
emacs-29, and neither on Ventura/arm64 nor Big Sur/x86_64 :-(.

Christian, can you reproduce this with emacs -Q?  Or does it perhaps
depend on your init.el?  (This was the case for me in the child frane
case that Alan fixed.)

Emacs29 -Q also crashes, but differently:

/Applications/Emacs-29.1.app/Contents/MacOS/Emacs --load=emacs28_desktop_load_init.el

    Fatal error 11: Segmentation fault

    Abort trap: 6

/Applications/Emacs-29.1.app/Contents/MacOS/Emacs -Q --load=emacs28_desktop_load_init.el

    objc[23222]: autorelease pool page 0x12a43c000 corrupted

      magic     0x2a05b000 0x00000001 0x000000eb 0x00000000

      should be 0xa1a1a1a1 0x4f545541 0x454c4552 0x21455341

      pthread   0x1e695e05d

      should be 0x1e695e080

    Fatal error 6: Aborted

    Abort trap: 6

with emacs28_desktop_load_init.el:

(setq desktop-path '("~/tmp/"))

(require 'desktop)

(desktop-read)

Emacs28 -Q doesn’t crash:

/Applications/Emacs-28.2.app/Contents/MacOS/Emacs --load=emacs28_desktop_load_init.el

    Fatal error 11: Segmentation fault

    Abort trap: 6

/Applications/Emacs-28.2.app/Contents/MacOS/Emacs -Q --load=emacs28_desktop_load_init.el

    ### no crash, desktop-read works

Weirder and weirder …

I tried to come up with a simpler desktop to trigger the crash, but 8 frames with the *scratch* buffer, 4 iconified, are not enough to trigger it. 

OTOH, opening two empty files 1 and 2 with 4 frames for each one and two frames of each file iconified triggers the crash in Emacs29 without the ‘-Q’, so only with my init-file involved.

Gerd, did you test with the .emacs.desktop files I attached to the bug report? My environment configures desktop-save to save iconified frames which standard Emacs doesn’t do. I have only seen crashes where there were more than 3 or 4 iconified frames in the .emacs.desktop.