[mythtv-commits] Ticket #1032: Divide by zero error in mythfrontend information screen

[MythTV]

#1032: Divide by zero error in mythfrontend information screen
----------------------------------------+-----------------------------------
 Reporter:  mythdev at penyball.cix.co.uk  |       Owner:  cpinkham
     Type:  defect                      |      Status:  new     
 Priority:  minor                       |   Milestone:  0.19    
Component:  mythtv                      |     Version:  head    
 Severity:  low                         |  
----------------------------------------+-----------------------------------
 If the recorded table is empty then selecting Information Centre/System
 Status/Machine Status segfaults with a divide by zero in
 disk_usage_with_rec_time_kb (statusbox.cpp) - because bytesPerMin is zero.

 This is caused by the first query in StatusBox::getActualRecordedBPS.

 Because this is computing a value it will always return a result = NULL
 when the recorded table is empty - in which case
 query.value(0).toDouble() will return 0. (mysql docs say that is what it
 is supposed to do) Unfortunately query.value(0).isValid() is true and
 query.value(0).isNull() is false
 so the only fix I can think of is as below:

 {{{
 Index: mythtv/programs/mythfrontend/statusbox.cpp
 ===================================================================
 --- mythtv/programs/mythfrontend/statusbox.cpp  (revision 8599)
 +++ mythtv/programs/mythfrontend/statusbox.cpp  (working copy)
 @@ -1063,8 +1063,13 @@
      query.prepare(querystr.arg(hostnames));

      if (query.exec() && query.isActive() && query.size() > 0 &&
 query.next())
 +    {
 +        if ( query.value(0).toDouble() == 0 )
 +            return;  // recorded table was empty
 +
          recordingProfilesBPS[QObject::tr("average")] =
              (int)(query.value(0).toDouble());
 +    }

      querystr =
          "SELECT max(filesize * 8 / "
 }}}

 This is at svn 8599 with mysql 4.0

-- 
Ticket URL: <http://cvs.mythtv.org/trac/ticket/1032>
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