#443 BadWindow (invalid Window parameter) on conky startup after logging into desktop environment

[Omega Weapon]

I have XFCE4 configured to start conky up when I log in. For some months now I have noticed that conky does not start up sometimes - I've finally had enough of this and have investigated.

conky is started correctly, however it quickly fails with the following X error:

X Error of failed request:  BadWindow (invalid Window parameter)
  Major opcode of failed request:  3 (X_GetWindowAttributes)
  Resource id in failed request:  0x4a00001
  Serial number of failed request:  121
  Current serial number in output stream:  122

When started manually, conky is fine - so clearly its a contention issue during the period where many programs are starting up.

After doing some research I was able to find why conky died (as compared to this just being an error) - default X error handlers were being used, which exit when hit - which is not acceptable to me as a user (good thing I am a programmer ;)).

A backtrace of the exit:

#0  __GI_exit (status=1) at exit.c:99
No locals.
#1  0x00007ffff66d1b98 in _XDefaultError () from /usr/lib/x86_64-linux-gnu/libX11.so.6
No symbol table info available.
#2  0x00007ffff66d1cdb in _XError () from /usr/lib/x86_64-linux-gnu/libX11.so.6
No symbol table info available.
#3  0x00007ffff66ced57 in ?? () from /usr/lib/x86_64-linux-gnu/libX11.so.6
No symbol table info available.
#4  0x00007ffff66cfe12 in _XReply () from /usr/lib/x86_64-linux-gnu/libX11.so.6
No symbol table info available.
#5  0x00007ffff66b6ac6 in XGetWindowProperty () from /usr/lib/x86_64-linux-gnu/libX11.so.6
No symbol table info available.
#6  0x0000000000419bfc in find_desktop_window (p_desktop=0x673730 <window+16>, p_root=0x673720 <window>) at ../../src/x11.c:130
        type = 0
        format = 0
        i = <optimized out>
        nitems = 0
        bytes = 0
        n = 104
        root = 703
        win = 703
        troot = 703
        parent = 0
        children = 0x6c37c0
        buf = 0x0
#7  0x000000000041a09e in init_window (own_window=1, w=10, h=10, set_trans=<optimized out>, back_colour=<optimized out>, argv=argv@entry=0x7fffffffe888, argc=argc@entry=1) at ../../src/x11.c:281
        depth = 0
        flags = <optimized out>
        visual = 0x0
#8  0x000000000043281c in X11_create_window () at ../../src/conky.c:4395
No locals.
#9  initialisation (argc=argc@entry=1, argv=argv@entry=0x7fffffffe888) at ../../src/conky.c:5812
        act = {__sigaction_handler = {sa_handler = 0x6a897f, sa_sigaction = 0x6a897f}, sa_mask = {__val = {0, 0, 0, 0, 0, 17184406103, 4536906, 4521984, 0, 4536906, 4536906, 4536919, 0, 0, 0, 4294967295}}, sa_flags = 0, 
          sa_restorer = 0xf494d6f0}
        oact = {__sigaction_handler = {sa_handler = 0x0, sa_sigaction = 0x0}, sa_mask = {__val = {1, 140737488346912, 58, 258797660, 140737351927184, 0, 28, 4043713, 140737349680896, 140737349680340, 4536906, 126366, 140737349680896, 
              6918624, 140737349685432, 6917226}}, sa_flags = -190586008, sa_restorer = 0x0}
#10 0x0000000000409a9f in main (argc=1, argv=0x7fffffffe888) at ../../src/conky.c:5953
        s = 0x7fffffffee4f "en_GB.UTF-8"
        temp = <optimized out>
        x = <optimized out>

I have since implemented a basic X error handler that ignores errors - after 4 X errors occur, conky starts up correctly.

I was about to attach the patch when I noticed that lack of X error handlers was an explicit choice - see conky.c x11_error_handler function, ~line 4345, that is only used when DEBUG is enabled - and even when it is available it promptly aborts!

So, I have to open this ticket up as discussion - why let a non-fatal error kill conky?

conky -V:

Conky 1.9.0 compiled Sun Oct  6 18:56:00 BST 2013 for Linux 3.10-3-amd64 (x86_64)

Compiled in features:

System config file: /usr/local/etc/conky/conky.conf
Package library path: /usr/local/lib/conky

 X11:
  * Xdamage extension
  * XDBE (double buffer extension)
  * Xft
  * ARGB visual

 Music detection:
  * MPD
  * MOC

 General:
  * math
  * hddtemp
  * portmon
  * config-output
  * apcupsd
  * iostats
  * ncurses
  * Lua

  Lua bindings: