[mythtv-users] mythcommflag and mythpreviewgen segmentation faults

[djh999gc at gmail.com]

Tracking down why commflag stopped working on 0.24-fixes after 12/14/10.

Seeing segmentation faults in the messages log & mythbackendlog like
these:

#####
2010-12-16 22:00:42.626 RecBase(1:1):
GetKeyframePositions(948,9223372036854775807,#4) out of 33 Segmentation
fault 2010-12-16 22:10:55.250 MainServer::ANN Monitor
...
2010-12-16 20:55:51.665 adding: mythux as a client (events: 1)
Segmentation fault
2010-12-16 20:55:52.132 Preview Error: Encountered problems running
'/usr/bin/mythpreviewgen --size 0x0 --chanid 1081 --starttime
20101216200000  > /dev/null'
#####
kernel: [26794.275322] mythpreviewgen[5796]: segfault at 0 ip
00007fb89984ffd4 sp 00007fb87db94e20 error 4 in
libmythtv-0.24.so.0.24.0[7fb8991ac000+c91000] Dec 16 22:39:45 mythux
kernel: [26794.413234] mythpreviewgen[5797]: segfault at 0 ip
00007fec36f7ffd4 sp 00007fec17a42e20 error 4 in
libmythtv-0.24.so.0.24.0[7fec368dc000+c91000] Dec 16 22:40:54 mythux
kernel: [26864.301370] mythcommflag[5800]: segfault at 0 ip
00007ffa0a583fd4 sp 00007ff9f8a4ce20 error 4 in
libmythtv-0.24.so.0.24.0[7ffa09ee0000+c91000] Dec 16 22:43:30 mythux
kernel: [27019.648649] mythcommflag[5820]: segfault at 0 ip
00007f5f03939fd4 sp 00007f5edec0fe20 error 4 in
libmythtv-0.24.so.0.24.0[7f5f03296000+c91000]
#####

So, I looked through the list & saw suggestions to optimize_mythdb.sh,
(done), then to rebuild seek tables for the affected recordings
(done).  mythcommflag --rebuild finished ok.

Next attempted to commflag the rebuilt show like this & see same
segmentation fault result in the preview generation:

#####
$ mythcommflag --hogcpu -c 1391 -s 20101216210000
2010-12-16 22:43:29.855 Using runtime prefix = /usr
2010-12-16 22:43:29.856 Using configuration directory
= /home/myth/.mythtv 2010-12-16 22:43:29.856 Empty LocalHostName.
2010-12-16 22:43:29.881 New DB connection, total: 1
2010-12-16 22:43:29.889 Closing DB connection named 'DBManager0'
2010-12-16 22:43:29.895 mythcommflag version: 0.24.20101129-1
www.mythtv.org 2010-12-16 22:43:29.895 Enabled verbose msgs: important

MythTV Commercial Flagger, started at Thu Dec 16 22:43:29 2010
Flagging commercial breaks for:
ChanID  Start Time      Title
Breaks ------  --------------
-----------------------------------------  ------ 1391   20101216210000
The Office                                2010-12-16 22:43:29.956 New
DB connection, total: 2 2010-12-16 22:43:29.966 Using protocol version
63 Finding LogoSegmentation fault
#####