QGIS » QGIS Application

no reproducable with 8545ed7e (SVN r12664) here.

Tested under linux and windows, both with qgis 1.4 and trunk, overview window docked on both sides. Not reproducable here.

this is strange: I can't reproduce it on my computer at work, but it's still there on my private computer (which is only 3 months old). Maybe it has to do with the graphica card? Anyway, the very same project loaded in Qgis 1.3 behaves OK, whereas it crashes in 1.4.
I will do some more experimentation in the coming weeks, and will report when I have any news.

Hubert

Hi,
it would be great to see what the console returns when qgis crashes. Do you have any linux installation in your pc?

Lutra,

I don't have Linux on my PC. This is what info I get from Windows after the crash:

Error signature: see jpg in the appendix
Exception information (the first part of it, too large to show all): see jpg
Additional information added to the error report: see txt

It all makes no sense to me but I hope it does so to you!

Hubert

Still not able to replicate this on both windows (xp) and linux. Can you replicate the problem on more than one machine, in order to rule out local configuration problems?

I found out that Qgis only crashes when Actions->Options->Use cache when rendering is turned ON. When OFF no problems.

Hubert

Ok, this is confirmed also under linux.

Terminal says

"Warning: QPaintDevice: Cannot destroy paint device that is being painted
Segmentation fault" 

might be related to #2714.

Replying to [comment:11 jef]:

might be related to #2714.

if the workaround for #2714 has fixed it then it does not work for this bug. It is pretty easy to reproduce on trunk but I also found vectors that do not cause qgis to crash.

Replying to [comment:12 lutra]:

Replying to [comment:11 jef]:

might be related to #2714.

if the workaround for #2714 has fixed it then it does not work for this bug. It is pretty easy to reproduce on trunk but I also found vectors that do not cause qgis to crash.

I've just installed 1.5 and am unable to reproduce. N.B. that for me 1.4 only crashed sometimes - not every time I moved the border.

Unable to reproduce it using QGis trunk (0d74e285 (SVN r13959)) on Ubuntu 9.04

Replying to [comment:15 brushtyler]:

Unable to reproduce it using QGis trunk (0d74e285 (SVN r13959)) on Ubuntu 9.04

Hi Giuseppe,

it is not replicable with all vectors. I also found vectors that do not cause the crash.

Replying to [comment:16 lutra]:

Replying to [comment:15 brushtyler]:

Unable to reproduce it using QGis trunk (0d74e285 (SVN r13959)) on Ubuntu 9.04

Hi Giuseppe,

it is not replicable with all vectors. I also found vectors that do not cause the crash.

I tried more than one vector but nothing.

Could you attach a vector file which may cause the crash?

With this

http://www.iambiente.pt/atlas/dl/regista_dl.jsp?zona=continente&grupo=&tema=c_curvasnivel

for me is instant crash even with "Use cache when rendering" OFF.

I'm using qgis 1.5 under Ubuntu 10.04

gio@sibirica:~$ qgis
Python support ENABLED :-) 
Loaded : [[GdalTools]] (package: [[GdalTools]])
Warning: QHttp: empty path requested is invalid -- using '/'
Loaded : Plugin Installer (package: plugin_installer)
Loaded : fTools (package: fTools)
Loaded : [[OpenStreetMap]] plugin (package: osm)
Loaded : [[MapServer]] Export (package: mapserver_export)
gio@sibirica:~$ qgis
Python support ENABLED :-) 
Loaded : [[GdalTools]] (package: [[GdalTools]])
Warning: QHttp: empty path requested is invalid -- using '/'
Loaded : Plugin Installer (package: plugin_installer)
Loaded : fTools (package: fTools)
Loaded : [[OpenStreetMap]] plugin (package: osm)
Loaded : [[MapServer]] Export (package: mapserver_export)
Warning: QPixmap::operator=: Cannot assign to pixmap during painting
Warning: QPainter::begin: A paint device can only be painted by one painter at a time.
Warning: QPainter::end: Painter not active, aborted
Warning: QPixmap::operator=: Cannot assign to pixmap during painting
Warning: QPainter::begin: A paint device can only be painted by one painter at a time.
Warning: QPainter::end: Painter not active, aborted
Warning: QPixmap::operator=: Cannot assign to pixmap during painting
Warning: QPainter::begin: A paint device can only be painted by one painter at a time.
Warning: QPainter::end: Painter not active, aborted
Warning: QPixmap::operator=: Cannot assign to pixmap during painting
Warning: QPainter::begin: A paint device can only be painted by one painter at a time.
Warning: QPainter::end: Painter not active, aborted
Warning: QPixmap::operator=: Cannot assign to pixmap during painting
Warning: QPainter::begin: A paint device can only be painted by one painter at a time.
Warning: QPainter::end: Painter not active, aborted
Segmentation fault

Ok, now I'm able to reproduce it too (QGis trunk 0d74e285 (SVN r13959) on Ubuntu 9.04)

Replying to [comment:18 lutra]:

With this

http://www.iambiente.pt/atlas/dl/regista_dl.jsp?zona=continente&grupo=&tema=c_curvasnivel

for me is instant crash even with "Use cache when rendering" OFF.

For me only if the cache render is enabled.

Before crash, the terminal displays this message:

"Warning: QPaintDevice: Cannot destroy paint device that is being painted
Segmentation fault" 

This message is displayed from

/home/brushtyler/Projects/Work/Faunalia/qgis/qgis_unstable/src/core/qgsmaplayer.cpp: 848

delete mpCacheImage;

So I think that when the render is disabled the crash is related to a different issue.

Might be due to Qt? Could you please try again with current trunk, and report which Qt version you use?

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.

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.

Replying to [comment:24 brushtyler]:

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.

Found, no extra-call (would be very strange!), but it's a race condition, see the attachment.

Look at the attachment qgis_ticket_2339_bt:

at line 95 you can see the missing "before qApp->processEvents()"

and after a refreshing of the layer

at line 189 there's the related "after qApp->processEvents()"