Bug 277099 – media-libs/mesa-7.3-r1 has unitialized data that leads to mythfrontend crash

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Olav Sandstå 2009-07-08 20:47:19 UTC]

After upgrading to media-libs/mesa-7.3-r1 mythfrontend crashes during startup. 

Reproducible: Always

Steps to Reproduce:
1. Upgrade to media-libs/mesa-7.3-r1 
2. start mythfrontend
3.

Actual Results:  
The result is that mythfrontend crashes with the following call stack:

#0  0x6f732e4c in ?? ()
#1  0xb5f984fc in glXWaitX () at glxcmds.c:660
#2  0xb654c34f in QGLWidget::resizeEvent () from /usr/qt/3/lib/libqt-mt.so.3
#3  0xb6317c9f in QWidget::event () from /usr/qt/3/lib/libqt-mt.so.3
#4  0xb6277075 in QApplication::internalNotify ()
   from /usr/qt/3/lib/libqt-mt.so.3
#5  0xb627844f in QApplication::notify () from /usr/qt/3/lib/libqt-mt.so.3
#6  0xb62790da in QApplication::sendPostedEvents ()
   from /usr/qt/3/lib/libqt-mt.so.3
#7  0xb6316c35 in QWidget::show () from /usr/qt/3/lib/libqt-mt.so.3
#8  0xb69a6c75 in MythMainWindow::Show () from /usr/lib/libmythui-0.21.so.0
#9  0xb69a8630 in MythMainWindow::Init () from /usr/lib/libmythui-0.21.so.0
#10 0x0806d6e4 in ?? ()
#11 0xb5be0711 in __libc_start_main () from /lib/libc.so.6
#12 0x080621b1 in ?? ()




This crash is caused by two uninitialized variables in the Mesa code: in function driCreateScreen the the psp->waitX and psp->waitGL is not initialized. These should be initialized to NULL.

This is reported in the following bug report:

http://bugs.freedesktop.org/show_bug.cgi?id=21053

[Comment 1 Olav Sandstå 2009-07-08 20:51:46 UTC]

Created attachment 197254 [details, diff]
Patch that initializes the two unitialized variables

This patch is based on the patch attached to the original bug report found here:

http://bugs.freedesktop.org/show_bug.cgi?id=21053

This patch solves the problem with mythfrontend crashing during startup

[Comment 2 Tom Dexter 2009-07-09 23:30:17 UTC]

Just a note:  This bug does not appear to affect nVidia drivers.

I ran into this bug trying to run mythtv-setup on my stand-alone backend which has an Intel 82865G card.  However I had no problem with my frontend (with an nVidia card), and could also run mythtv-setup on the backend via ssh and X11Forwarding from any machine with an nVidia card.  I could also run it if I forced indirect rendering with:

export LIBGL_ALWAYS_INDIRECT=1

I applied the above patch in an ebuild in my overlay and it fixed the issue altogether.

[Comment 3 Olav Sandstå 2009-07-10 08:47:29 UTC]

(In reply to comment #2)

Thanks for the update and for the suggested work-around. My crash happened for the mga driver using a Matrox 450 card.

Thanks also for verifying that the patch works and solves the problem.

[Comment 4 Tomáš Chvátal (RETIRED) 2009-08-21 06:57:40 UTC]

Fixed in both latest versions (7.5 and 7.4).
We wont backport the fixes, rather update.