Re: 23.0.60; restarting X causes emacsclient display bugs

[Dan Nicolaescu]

Tom Rauchenwald <address@hidden> writes:

  > Hi,
  > 
  > I try running emacs inside screen, and open frames to it with emacsclient.
  > This works fine, until I need to restart the X server for whatever
  > reason. newly created X frames don't update properly when scrolling
  > (part of the text stays), the mode-line faces are not right
  > (background is black) and the modeline isn't cleared before it
  > updates, so after switching a few buffers only garbage is in it.
  > 
  > To reproduce:
  > 1) start emacs in a detached screen
  > screen -dmS emacsserver emacs -nw -Q --eval '(setq server-name "foo")'
  > -f server-start
  > 2) open an X frame
  > emacsclient -s foo -c -d :0
  > 3) close the X frame and restart X
  > 4) open an X frame (the first try always fails for me, so you may need
  > to do it twice
  > emacsclient -s foo -c -d :0 
  > 
  > This frame shows various redisplay problems, for example when browsing
  > through a buffer with C-n (here only half of the screen is updated,
  > but it seems to be connected to scoll-conservatively).
  > Note that tty frames (emacsclient -t) work fine. 
  > 
  > Can anyone reproduce this? What other information do you need?

Thank you. Here's a simpler way to reproduce this:

emacs -Q -nw -f server-start
from another xterm:
emacsclient -c -d :0

from yet another xterm:

xkill

and click on the X11 frame created by emacsclient


(gdb) bt
#0  internal_condition_case_2 (bfun=0x81699d0 <Frun_hook_with_args>, nargs=2, 
    args=0xbfba9384, handlers=137657705, hfun=0x805d5d0 <delete_frame_handler>)
    at /home/dann/emacs/src/eval.c:1568
#1  0x0805def1 in Fdelete_frame (frame=146496652, force=137657705)
    at /home/dann/emacs/src/frame.c:1412
#2  0x080d8fb1 in x_connection_closed (dpy=0x858e9c8, 
    error_message=<value optimized out>)
    at /home/dann/emacs/src/xterm.c:8054
#3  0x080d906b in x_io_error_quitter (display=0x858e9c8)
    at /home/dann/emacs/src/xterm.c:8202
#4  0x00826fc2 in _XIOError () from /usr/lib/libX11.so.6
#5  0x0082dbb9 in ?? () from /usr/lib/libX11.so.6
#6  0x0082df9f in _XEventsQueued () from /usr/lib/libX11.so.6
#7  0x008176d2 in XPending () from /usr/lib/libX11.so.6
#8  0x080d90fe in XTread_socket (terminal=0x85d3898, expected=1, 
hold_quit=0xbfba9c64)
    at /home/dann/emacs/src/xterm.c:7366
#9  0x08105adf in read_avail_input (expected=1)
    at /home/dann/emacs/src/keyboard.c:7110
#10 0x08105c0a in handle_async_input ()
    at /home/dann/emacs/src/keyboard.c:7340
#11 0x08105dd1 in input_available_signal (signo=29)
    at /home/dann/emacs/src/keyboard.c:7382
#12 <signal handler called>
#13 0x00110402 in __kernel_vsyscall ()
#14 0x00cbb5bd in ___newselect_nocancel () from /lib/libc.so.6
#15 0x08195325 in select_wrapper (n=1, rfd=0x0, wfd=0xbfbaa1e8, xfd=0x0, 
tmo=0xbfbaa318)
    at /home/dann/emacs/src/process.c:4240
#16 0x08198530 in wait_reading_process_output (time_limit=30, microsecs=0, 
read_kbd=-1, 
    do_display=1, wait_for_cell=137657657, wait_proc=0x0, just_wait_proc=0)
    at /home/dann/emacs/src/process.c:4610
#17 0x08052ce0 in sit_for (timeout=240, reading=1, do_display=1)
    at /home/dann/emacs/src/dispnew.c:6608
#18 0x0810af8d in read_char (commandflag=1, nmaps=2, maps=0xbfbaa5f0, 
    prev_event=137657657, used_mouse_menu=0xbfbaa698, end_time=0x0)
    at /home/dann/emacs/src/keyboard.c:2969
#19 0x0810ceca in read_key_sequence (keybuf=0xbfbaa734, bufsize=30, 
prompt=137657657, 
    dont_downcase_last=0, can_return_switch_frame=1, fix_current_buffer=1)
    at /home/dann/emacs/src/keyboard.c:9460
#20 0x0810ed63 in command_loop_1 ()
    at /home/dann/emacs/src/keyboard.c:1655
#21 0x08166ed2 in internal_condition_case (bfun=0x810ebc0 <command_loop_1>, 
    handlers=137701849, hfun=0x8109140 <cmd_error>)
    at /home/dann/emacs/src/eval.c:1494
#22 0x081085b3 in command_loop_2 ()
    at /home/dann/emacs/src/keyboard.c:1370
#23 0x08166f8a in internal_catch (tag=137696697, func=0x8108590 
<command_loop_2>, 
    arg=137657657) at /home/dann/emacs/src/eval.c:1230
#24 0x08108fa7 in command_loop ()
    at /home/dann/emacs/src/keyboard.c:1349
#25 0x0810930a in recursive_edit_1 ()
    at /home/dann/emacs/src/keyboard.c:958
#26 0x08109441 in Frecursive_edit ()
    at /home/dann/emacs/src/keyboard.c:1020
#27 0x080feb87 in main (argc=3, argv=0xbfbaae34)
    at /home/dann/emacs/src/emacs.c:1793


The abort is because of this code in internal_condition_case_2:

#if HAVE_X_WINDOWS
  if (x_catching_errors ())
    abort ();
#endif


x_connection_closed does an:

  x_catch_errors (dpy);

but the condition that x_catching_errors looks for is different.

Can someone that knows this code please look at this?