[Tuxmath-devel] Fullscreen issues

[Tim H. <ho...@wu...>]

Hi Brendan, David, et al,

I was seeing some unexplained X lockups related to fullscreen, and I finally 
traced the issue down. On my machine (ThinkPad T60), my two 
highest-resolution modes are 1400x1050 and 1280x1024. At work, I plug into a 
monitor with maximum resolution 1280x1024, so I often run my desktop at that 
resolution.

After some head-scratching, here's what I've determined:
1. If I run my laptop (using its screen only, not connected to the external 
monitor) at 1400x1050 mode, TuxMath fullscreen works fine.
2. If I have re-started X at work, plugged into the monitor and running at 
1280x1024, TuxMath fullscreen works fine.
3. If I'm running without the monitor, but running X & my desktop at 1280x1024 
anyway, then I was getting X lockups on fullscreen but not --windowed.

It turns out that the problem in situation #3 is that SDL_ListModes would 
still list 1400x1050 as the first entry, even though X was running at 
1280x1024. TuxMath tried to set 1400x1050 as the resolution, but this led to 
an X lockup (fixed by Ctrl-Alt-Backspace).

With some random experimentation, I finally figured out that the lockup can at 
least be avoided by _not_ using atexit() to register the cleanup 
function---then tuxmath "just" crashes (whew). So I replaced the atexit() 
registration of cleanup back to what it used to be, a direct call to cleanup. 
(Weird---I thought that's what atexit is supposed to be for, handling 
unexpected problems...) I've committed that change.

Now X doesn't lock up during a crash, instead I get the following output on 
the console:
X Error of failed request:  BadValue (integer parameter out of range for 
operation)
  Major opcode of failed request:  134 (XFree86-VidModeExtension)
  Minor opcode of failed request:  10 (XF86VidModeSwitchToMode)
  Value in failed request:  0x86
  Serial number of failed request:  109
  Current serial number in output stream:  111

Can anyone else verify that this is a problem, or is it just my combination of 
hardware/drivers? (I've tried both fbdev & fglrx). Does anyone know how one 
can determine the desktop's current resolution, so that we can avoid trying 
to set a too-high resolution? Or is this an SDL bug?

Best,
--Tim