comparison data/fileio/MIDIFileReader.cpp @ 964:6b5e1edd95fc

Fix to iterator invalidation (from coverity scan)

 {
     bool notesOnTrack = false;
     bool noteOffFound;
 
     for (MIDITrack::iterator i = m_midiComposition[track].begin();
-	 i != m_midiComposition[track].end(); i++) {
+	 i != m_midiComposition[track].end(); ) {
+
+        MIDITrack::iterator nexti = i;
+        ++nexti; 
 
         if ((*i)->getMessageType() == MIDI_NOTE_ON && (*i)->getVelocity() > 0) {
 
 	    notesOnTrack = true;
             noteOffFound = false;

                     ((*j)->getMessageType() == MIDI_NOTE_OFF ||
                     ((*j)->getMessageType() == MIDI_NOTE_ON &&
                      (*j)->getVelocity() == 0x00))) {
 
                     (*i)->setDuration((*j)->getTime() - (*i)->getTime());
+
+                    if (nexti == j) {
+                        // we're about to erase j, invalidating nexti
+                        // as well (but as this is a map, that is the
+                        // only iterator to be invalidated)
+                        ++nexti;
+                    }
 
                     delete *j;
                     m_midiComposition[track].erase(j);
 
                     noteOffFound = true;

 		MIDITrack::iterator j = m_midiComposition[track].end();
 		--j;
                 (*i)->setDuration((*j)->getTime() - (*i)->getTime());
 	    }
         }
+
+        i = nexti;
     }
 
     return notesOnTrack;
 }