added a sanity check to avoid a division by 0 in case the config file

contains bad data

1 files changed, 3 insertions, 1 deletions

diff --git a/core/launcher/screensaver.cpp b/core/launcher/screensaver.cpp
index 45da9ed..088ed19 100644
--- a/core/launcher/screensaver.cpp
+++ b/core/launcher/screensaver.cpp
@@ -185,12 +185,14 @@ void OpieScreenSaver::setBacklight ( int bright )
                         m_sensordata [LS_Interval] = 2000;      
                 
                 for ( uint i = 0; i < LS_Count; i++ ) {
                         if ( i < sl. count ( ))
                                 m_sensordata [i] = sl [i]. toInt ( );
                 }
+                if ( m_sensordata [LS_Steps] < 2 ) // sanity check to avoid SIGFPE
+                        m_sensordata [LS_Steps] = 2;
 
                 timerEvent ( 0 );
                 startTimer ( m_sensordata [LS_Interval] );
         }
 
         setBacklightInternal ( bright );
@@ -230,13 +232,13 @@ void OpieScreenSaver::timerEvent ( QTimerEvent * )
         else if ( s >= m_sensordata [LS_SensorMax] )
                 m_backlight_sensor = m_sensordata [LS_LightMin];
         else {
                 int dx = m_sensordata [LS_SensorMax] - m_sensordata [LS_SensorMin];
                 int dy = m_sensordata [LS_LightMax] - m_sensordata [LS_LightMin];
                 
-                int stepno = ( s - m_sensordata [LS_SensorMin] ) * m_sensordata [LS_Steps] / dx;
+                int stepno = ( s - m_sensordata [LS_SensorMin] ) * m_sensordata [LS_Steps] / dx; // dx is never 0
                 
                 m_backlight_sensor = m_sensordata [LS_LightMax] - dy * stepno / ( m_sensordata [LS_Steps] - 1 );
         }
         if ( !m_backlight_sensor )
                 m_backlight_sensor = 1;