Bugzilla Bug 167963

Upon installing libXrandr-1.2.0, mythfrontend segfaulted on load.  After
1.2.0-r1 got committed I was able to recompile mythtv against 1.2.0 but it
still segfaults on load.  Downgrading to 1.1.2 lets mythfrontend load.

Reproducible: Always

Steps to Reproduce:

http://www.gentoo.org/proj/en/qa/backtraces.xml

Also post emerge --info.

Since the seg is occurring in libXrandr and not myth, I only recompiled
libXrandr with debugging.

(gdb) bt
#0  0xa6d857f1 in _XRRGetScreenInfo (dpy=0x8269158, info=0x82683c8, window=84)
at XrrConfig.c:226
#1  0xa6d85c98 in XRRGetScreenInfo (dpy=0x8269158, window=84) at
XrrConfig.c:351
#2  0xa7014613 in ?? () from /usr/lib/libmyth-0.20.so.0
#3  0xa701488f in DisplayResX::GetVideoModes () from /usr/lib/libmyth-0.20.so.0
#4  0xa6fb5b29 in DisplayRes::Initialize () from /usr/lib/libmyth-0.20.so.0
#5  0xa7014d2a in DisplayResX::DisplayResX () from /usr/lib/libmyth-0.20.so.0
#6  0xa6fb413e in DisplayRes::GetDisplayRes () from /usr/lib/libmyth-0.20.so.0
#7  0xa6fb76d1 in GetVideoModes () from /usr/lib/libmyth-0.20.so.0
#8  0x080ce345 in ?? ()
#9  0x0805c5dd in ?? ()
#10 0x08068263 in ?? ()
#11 0x455c4823 in __libc_start_main () from /lib/libc.so.6

Portage 2.1.2-r10 (default-linux/x86/2006.1, gcc-4.1.2, glibc-2.5-r0,
2.6.20-ck1 i686)
=================================================================
System uname: 2.6.20-ck1 i686 Intel(R) Pentium(R) 4 CPU 3.00GHz
Gentoo Base System release 1.12.9
Timestamp of tree: Thu, 22 Feb 2007 23:20:01 +0000
dev-java/java-config: 1.3.7, 2.0.31-r3
dev-lang/python:     2.5-r1
dev-python/pycrypto: 2.0.1-r5
sys-apps/sandbox:    1.2.18.1
sys-devel/autoconf:  2.13, 2.61
sys-devel/automake:  1.4_p6, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2, 1.10
sys-devel/binutils:  2.17
sys-devel/gcc-config: 1.3.14
sys-devel/libtool:   1.5.23b
virtual/os-headers:  2.6.20
ACCEPT_KEYWORDS="x86 ~x86"
AUTOCLEAN="yes"
CBUILD="i686-pc-linux-gnu"
CFLAGS="-O2 -march=prescott -msse -msse2 -msse3 -mfpmath=sse
-fomit-frame-pointer -ftracer -pipe"
CHOST="i686-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/share/X11/xkb /var/www/localhost/htdocs"
CONFIG_PROTECT_MASK="/etc/env.d /etc/env.d/java/ /etc/gconf /etc/init.d
/etc/java-config/vms/ /etc/revdep-rebuild /etc/terminfo"
CXXFLAGS="-O2 -march=prescott -msse -msse2 -msse3 -mfpmath=sse
-fomit-frame-pointer -ftracer -pipe"
DISTDIR="/usr/portage/distfiles"
EMERGE_DEFAULT_OPTS="--alphabetical"
FEATURES="autoconfig distlocks noinfo parallel-fetch sandbox sfperms"
GENTOO_MIRRORS="http://mirror.espri.arizona.edu/gentoo/"
MAKEOPTS="-j3"
PKGDIR="/usr/portage/packages"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress
--force --whole-file --delete --delete-after --stats --timeout=180
--exclude=/distfiles --exclude=/local --exclude=/packages"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
PORTDIR_OVERLAY="/usr/local/portage"
SYNC="rsync://rsync.us.gentoo.org/gentoo-portage"
USE="X alsa apache2 bzip2 cups dbus expat gtk java jpeg lirc mad mmx mp3 mysql
ncurses nptl opengl pcre perl png python readline sse sse2 ssl
startup-notification truetype win32codecs x86 xinerama xslt xv xvid zlib"
ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1
emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m
maestro3 trident usb-audio via82xx via82xx-modem ymfpci"
ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file
hooks iec958 ioplug ladspa lfloat linear meter mulaw multi null plug rate route
share shm softvol" ELIBC="glibc" INPUT_DEVICES="keyboard mouse" KERNEL="linux"
LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses
text" LIRC_DEVICES="devinput" USERLAND="GNU" VIDEO_CARDS="mga"
Unset:  CTARGET, INSTALL_MASK, LANG, LC_ALL, LDFLAGS, LINGUAS,
PORTAGE_RSYNC_EXTRA_OPTS

recompile QT

I just compiled the new qt 3.3.8 and I'm still getting the same results.

It works for me on several machines. It's most likely related to your CFLAGS.

CFLAGS="-O2 -march=prescott -msse -msse2 -msse3 -mfpmath=sse
-fomit-frame-pointer -ftracer -pipe"

If you read the gcc documentation, prescott implies -msse -msse2 and -msse3, so
those are pointless.
-ftracer could be the source of your issue because of it's optimization
-fomit-frame-pointer is what's making your backtrace useless.
-mfpmath=sse could be the source of your problems as well. Why not let GCC
choose if the FPU or SSE units are better for floating point math at that
point.

All in all... remove the crap from your CFLAGS and recompile X and MythTV and I
doubt you'll have an issue.

*** Bug 183054 has been marked as a duplicate of this bug. ***

Eh, reopen...

https://bugs.launchpad.net/ubuntu/+source/mythtv/+bug/104262/comments/15

Looks like a fix was commited per http://svn.mythtv.org/trac/ticket/3401, if it
gets backported to -fixes as the anonymous posted asked. I'll make a new rev.

*** Bug 188354 has been marked as a duplicate of this bug. ***

Created an attachment (id=127746) [details]
Utilize the xrandr useflag

Upstream has a config option for disabling xrandr, so a possible workaround is
to make the ebuild utilize the xrandr useflag, then disable xrandr support
through it.

Causes more harm then good to remove xrandr support since the issue is that in
their code they assume that there's xrandr support. The flag isn't truly
honored.

I've have gotten upstream to address this in the 0.20 fixes branch as of
revision 14223. So it will be in the next rev bump. You can also always copy
the current MythTV ebuild into your own overlay and just rename it to
0.20_p14223 for the version.

fixed as of mythtv-0.20.2_p14282