bug#69287: 30.0.50; Pasting text from KDE clipboard sometimes crashes Emacs

[David Ponce <da_vid@orange.fr>]

On 21/02/2024 16:31, Eli Zaretskii wrote:
>> Cc: 69287@debbugs.gnu.org
>> Date: Wed, 21 Feb 2024 10:58:47 +0100
>> From: David Ponce <da_vid@orange.fr>
>>
>> xdisp.c:21778: Emacs fatal error: assertion failed: w->window_end_valid
>>
>> Thread 1 "emacs" hit Breakpoint 1, terminate_due_to_signal (sig=sig@entry=6, backtrace_limit=backtrace_limit@entry=2147483647)
>>      at emacs.c:442
>> 442       signal (sig, SIG_DFL);
>> (gdb) bt
>> #0  terminate_due_to_signal (sig=sig@entry=6, backtrace_limit=backtrace_limit@entry=2147483647) at emacs.c:442
>> #1  0x0000000000436698 in die
>>      (msg=msg@entry=0x717fce "w->window_end_valid", file=file@entry=0x717900 "xdisp.c", line=line@entry=21778) at alloc.c:8061
>> #2  0x0000000000427006 in find_first_unchanged_at_end_row (delta_bytes=<synthetic pointer>, delta=<synthetic pointer>, w=0x1065950)
>>      at xdisp.c:21778
>> #3  try_window_id (w=w@entry=0x1065950) at xdisp.c:22342
>> #4  0x00000000004c2dad in redisplay_window (window=<optimized out>, just_this_one_p=just_this_one_p@entry=true) at xdisp.c:20433
>> #5  0x00000000004c563e in redisplay_window_1 (window=window@entry=XIL(0x1065955)) at xdisp.c:18019
> 
> Do you have some optional feature enabled that resizes the mini-window
> at random points in time?  Like some optional completion package that
> sinerts a lot of stuff into the mini-window and thus causes it to
> resize?

No.  However I use my own library that provides tabs in the tab-line
(kind of alternative implementation of tab-line.el), and I noticed that
the "assertion failed: w->window_end_valid" only occurs when the tab-line
is used (globally set).  My tab-line extensively uses text properties:
display (images, space), help-echo and keymap, plus some other specific
properties.

> 
> IOW, we need a reproducible recipe for debugging this assertion
> violation.  If you can trigger this from "emacs -Q", it would be even
> better.

I am trying to get a reproducible recipe as simple as possible from
"emacs -Q".  I will post news here, if I manage to get something
interesting.
  
> 
> However, please note that this is assertion violation has nothing
> apparent to do with the previous crashes, which were inside GC.

I agree.  Unfortunately this display issue prevent me to go further
with the previous crash in GC.

Thanks