Hi!
I got another emacs crash, this time I was using 30.1 with both Pip's patch and the gcc flag -fno-tree-sra during compilation, although the crash is probably unrelated, as it is in redisplay instead of GC. The crash also coincided with my Windows computer (remember I am using Cygwin/X to ssh to a linux machine to open up an emacsclient) being forcefully restarted with a frame open. Unfortunately, I have no way of knowing with certainty that the crash happened during my Windows restart, as both took place overnight.
I have included the backtrace below, it seems that displayed_buffer is not a valid address.
Thread 1 "emacs" received signal SIGSEGV, Segmentation fault.
0x000000000047df16 in redisplay_window_1 (window=window@entry=0x1d17b245)
at xdisp.c:18029
warning: 18029 xdisp.c: No such file or directory
(gdb) bt full
#0 0x000000000047df16 in redisplay_window_1 (window=window@entry=0x1d17b245) at xdisp.c:18029
No locals.
#1 0x00000000005a7ea9 in internal_condition_case_1 (bfun=bfun@entry=0x47df0f <redisplay_window_1>, arg=0x1d17b245, handlers=<optimized out>, hfun=hfun@entry=0x43ee0b <redisplay_window_error>) at eval.c:1637
val = <optimized out>
c = 0xe0fda0
#2 0x000000000046cfe8 in redisplay_internal () at xdisp.c:17526
mini_window = <optimized out>
mini_window = <optimized out>
mini_frame = <optimized out>
w = 0x257ca838
sw = <optimized out>
fr = <optimized out>
pending = false
must_finish = <optimized out>
match_p = <optimized out>
tlbufpos = {charpos = 8573, bytepos = 330795424}
tlendpos = <optimized out>
number_of_visible_frames = 4
sf = 0x191ebd60
polling_stopped_here = <optimized out>
tail = <optimized out>
frame = <optimized out>
MAX_HSCROLL_RETRIES = MAX_HSCROLL_RETRIES
hscroll_retries = <optimized out>
MAX_GARBAGED_FRAME_RETRIES = MAX_GARBAGED_FRAME_RETRIES
garbaged_frame_retries = <optimized out>
consider_all_windows_p = <optimized out>
update_miniwindow_p = <optimized out>
count = <optimized out>
retry_frame = <optimized out>
#3 0x000000000046d411 in redisplay_preserve_echo_area (from_where=from_where@entry=8) at xdisp.c:17749
count = <optimized out>
#4 0x000000000053610a in detect_input_pending_run_timers (do_display=do_display@entry=true) at keyboard.c:11576
old_timers_run = 7077069
#5 0x00000000005f8c73 in wait_reading_process_output (time_limit=time_limit@entry=0, nsecs=nsecs@entry=0, read_kbd=read_kbd@entry=-1, do_display=do_display@entry=true, wait_for_cell=wait_for_cell@entry=0x0, wait_proc=wait_proc@entry=0x0, just_wait_proc=0) at process.c:5844
leave = false
process_skipped = false
wrapped = <optimized out>
channel_start = <optimized out>
child_fd = <optimized out>
last_read_channel = 57
channel = <optimized out>
nfds = 0
Available = {fds_bits = {7157535148594949416, 13839864582178052, 9007199254740992, 0 <repeats 13 times>}}
Writeok = {fds_bits = {0 <repeats 16 times>}}
check_write = <optimized out>
check_delay = <optimized out>
no_avail = false
xerrno = 11
proc = <optimized out>
timeout = {tv_sec = 0, tv_nsec = 6772189}
end_time = <optimized out>
timer_delay = <optimized out>
--Type <RET> for more, q to quit, c to continue without paging--c
got_output_end_time = <optimized out>
MINIMUM = MINIMUM
TIMEOUT = TIMEOUT
FOREVER = FOREVER
wait = FOREVER
got_some_output = -1
prev_wait_proc_nbytes_read = 0
retry_for_async = <optimized out>
count = <optimized out>
now = <optimized out>
#6 0x00000000005366d9 in kbd_buffer_get_event (kbp=kbp@entry=0x7fffffffdb08, used_mouse_menu=used_mouse_menu@entry=0x7fffffffe0bb, end_time=end_time@entry=0x0) at keyboard.c:4094
do_display = true
obj = <optimized out>
str = <optimized out>
had_pending_selection_requests = false
had_pending_conversion_events = false
#7 0x00000000005370d4 in read_event_from_main_queue (end_time=end_time@entry=0x0, local_getcjmp=local_getcjmp@entry=0x7fffffffde30, used_mouse_menu=used_mouse_menu@entry=0x7fffffffe0bb) at keyboard.c:2330
c = 0x0
save_jump = {{__jmpbuf = {0, 0, 0, 0, 0, 0, 0, 0}, __mask_was_saved = 0, __saved_mask = {__val = {0 <repeats 16 times>}}}}
kb = 0x6df4b30
count = <optimized out>
#8 0x000000000053724a in read_decoded_event_from_main_queue (end_time=end_time@entry=0x0, local_getcjmp=local_getcjmp@entry=0x7fffffffde30, prev_event=prev_event@entry=0x0, used_mouse_menu=used_mouse_menu@entry=0x7fffffffe0bb) at keyboard.c:2393
nextevt = <optimized out>
frame = <optimized out>
terminal = <optimized out>
events = {0x0, 0xffffffffffffffff, 0x0, 0x330b335, 0x0, 0x684dda38, 0x2f4ee1e9, 0x0, 0x684dda38, 0x307e0271, 0x3c, 0x0, 0x11fd0, 0x330b335, 0xc8ef563, 0xf4bec416f5a4e600}
n = 0
#9 0x0000000000538668 in read_char (commandflag=1, map=map@entry=0x1645e493, prev_event=0x0, used_mouse_menu=used_mouse_menu@entry=0x7fffffffe0bb, end_time=end_time@entry=0x0) at keyboard.c:3015
c = 0x0
local_getcjmp = {{__jmpbuf = {0, 6459013156217622215, 0, 140737488346880, 0, 13113857, -6459042925873656121, 6459043636991954631}, __mask_was_saved = 0, __saved_mask = {__val = {2, 0, 5991556, 67072736, 111988528, 109922016, 5863938, 0, 67072736, 98399184, 5864240, 109922032, 5510427, 0, 4625762720, 0}}}}
save_jump = {{__jmpbuf = {0, 0, 0, 0, 0, 0, 0, 0}, __mask_was_saved = 0, __saved_mask = {__val = {0 <repeats 16 times>}}}}
tem = <optimized out>
save = <optimized out>
previous_echo_area_message = 0x0
also_record = 0x0
reread = false
recorded = false
polling_stopped_here = true
orig_kboard = 0x6df4b30
jmpcount = <optimized out>
#10 0x0000000000539789 in read_key_sequence (keybuf=keybuf@entry=0x7fffffffe1e0, prompt=prompt@entry=0x0, dont_downcase_last=dont_downcase_last@entry=false, can_return_switch_frame=can_return_switch_frame@entry=true, fix_current_buffer=fix_current_buffer@entry=true, prevent_redisplay=prevent_redisplay@entry=false,
disable_text_conversion_p=false) at keyboard.c:10743
interrupted_kboard = 0x6df4b30
interrupted_frame = 0x191ebd60
key = <optimized out>
used_mouse_menu = false
echo_local_start = 0
last_real_key_start = 0
keys_local_start = 0
new_binding = <optimized out>
count = <optimized out>
t = 0
echo_start = 0
keys_start = 0
current_binding = 0x1645e493
first_unbound = 31
mock_input = 0
used_mouse_menu_history = {false <repeats 30 times>}
fkey = {parent = 0x189f853, map = 0x189f853, start = 0, end = 0}
keytran = {parent = 0x15554f4f941b, map = 0x15554f4f941b, start = 0, end = 0}
indec = {parent = 0x189f863, map = 0x189f863, start = 0, end = 0}
shift_translated = false
delayed_switch_frame = 0x0
original_uppercase = 0x0
original_uppercase_position = -1
disabled_conversion = false
starting_buffer = 0x13b789a0
fake_prefixed_keys = 0x0
first_event = 0x0
second_event = <optimized out>
#11 0x000000000053ac06 in command_loop_1 () at keyboard.c:1429
cmd = <optimized out>
keybuf = {0x11ac0, 0x15f855d3, 0x133e0, 0x5982d3 <set_default_internal+530>, 0x7fffffffe260, 0x2, 0x30, 0x1785bba5, 0x0, 0x5a770f <do_one_unbind+319>, 0x1804610, 0x60, 0x0, 0x0, 0x0, 0x5a8d59 <unbind_to+105>, 0xb, 0x111c0, 0x30, 0x1785bba5, 0x7bc0, 0xf4bec416f5a4e600, 0xcf32a0 <globals>, 0x1566b533, 0x60,
0x52f4c6 <cmd_error+363>, 0x0, 0xf4bec416f5a4e600, 0x60, 0x15554edf4d83}
i = <optimized out>
last_pt = <optimized out>
prev_modiff = 396499
prev_buffer = 0x13b789a0
#12 0x00000000005a7e25 in internal_condition_case (bfun=bfun@entry=0x53a9ce <command_loop_1>, handlers=handlers@entry=0x90, hfun=hfun@entry=0x52f35b <cmd_error>) at eval.c:1613
val = <optimized out>
c = 0xe0fc60
#13 0x00000000005292ae in command_loop_2 (handlers=handlers@entry=0x90) at keyboard.c:1168
val = <optimized out>
#14 0x00000000005a7d42 in internal_catch (tag=tag@entry=0x122d0, func=func@entry=0x529294 <command_loop_2>, arg=arg@entry=0x90) at eval.c:1292
val = <optimized out>
c = 0xea0f40
#15 0x000000000052926b in command_loop () at keyboard.c:1146
No locals.
#16 0x000000000052eec4 in recursive_edit_1 () at keyboard.c:754
count = <optimized out>
val = <optimized out>
#17 0x000000000052f25c in Frecursive_edit () at keyboard.c:837
count = <optimized out>
buffer = <optimized out>
#18 0x0000000000528660 in main (argc=<optimized out>, argv=0x7fffffffe5a8) at emacs.c:2635
stack_bottom_variable = 0x155553f84458 <_gnutls_lib_state>
old_argc = <optimized out>
dump_file = 0x0
no_loadup = false
junk = 0x0
dname_arg = 0x0
ch_to_dir = 0x0
original_pwd = 0x0
dump_mode = <optimized out>
skip_args = 1
temacs = 0x0
attempt_load_pdump = <optimized out>
only_version = false
rlim = {rlim_cur = 18446744073709551615, rlim_max = 18446744073709551615}
lc_all = <optimized out>
sockfd = -1
module_assertions = <optimized out>
(gdb) p displayed_buffer
$1 = (struct buffer *) 0xfffffffffffffffb