[QGIS-trac] Re: [Quantum GIS] #2339: QGis crashes when moving border between map canvas and overview map and "use render caching..." enabled

[Quantum GIS]

#2339: QGis crashes when moving border between map canvas and overview map and
"use render caching..." enabled
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   Reporter:  kivih1                                     |              Owner:               
       Type:  bug                                        |             Status:  new          
   Priority:  critical: causes crash or data corruption  |          Milestone:  Version 1.6.0
  Component:  MapCanvas                                  |            Version:  Trunk        
   Keywords:  map canvas, overview window                |   Platform_version:  SP3          
   Platform:  All                                        |           Must_fix:  Yes          
Status_info:  0                                          |  
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Comment(by brushtyler):

 Replying to [comment:23 lutra]:
 > tested again with trunk, on ubuntu 10.04 and 10.10 (different libqt4
 versions), render caching on and off and it is always instant crash.
 I made further tests. I found that segfault is dued to the processEvent()
 calls in QgsVectorLayer (!QgsVectorLayer.cpp:1045).

 Searching for similar Qt bugs, I found #2714 (maybe the same bug??), and
 also Martin wrote the problem is caused by processEvent(). The crash
 happens in Qt libraries.

 I discovered another piece, it's caused by an invalid extra-call. If I add
 debug messages both before (!QgsVectorLayer.cpp:1039) and after
 (!QgsVectorLayer.cpp:1055) the qapp->processEvent() call I notice that
 there are N pre-call messages and N+1 post-call messages.

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Ticket URL: <https://trac.osgeo.org/qgis/ticket/2339#comment:24>
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