[Qgis-developer] Issue with QgsVectorLayerUndoCommand class (QGIS crashes)

Tue Jul 19 13:12:28 PDT 2016

Hi All,

just to let you know that I created an issue in the QGIS issue Tracking
with this problem:

http://hub.qgis.org/issues/15311

Regards,

Germán

2016-07-15 12:26 GMT-05:00 Germán Carrillo <carrillo.german at gmail.com>:

> Hi All,
>
> I've discovered an issue with QgsVectorLayerUndoCommand class
> (QgsVectorLayerUndoCommandChangeAttribute.undo() method) when updating an
> attribute value after featureAdded SIGNAL is emitted.
>
> Steps to reproduce:
>
> 1. Open QGIS, load a sample vector layer like this (
> http://downloads.tuxfamily.org/tuxgis/tmp/test_point.zip ) and select it
> in the Layer List Widget (ToC).
> 2. Run the following code snippet into the QGIS Python Console to connect
> featureAdded SIGNAL  to a custom SLOT that changes an attribute value:
>
> ##################
> myLayer = iface.activeLayer()
> field = 0   # Please use the test Shapefile provided, if not, adjust the
> field index
>
> def updateFeatureAttrs( fId ):
>     f = myLayer.getFeatures( QgsFeatureRequest( fId ) ).next()
>     geom = f.geometry()
>     myLayer.changeAttributeValue( fId, field, geom.asPoint().x() )
>
> myLayer.featureAdded.connect( updateFeatureAttrs )
> ##################
>
> 3. Start editing. Add a new point. (If a form opens click on OK). Don't
> save anything.
> 4. Stop editing and choose "Close without saving."
> 5. QGIS crashes and prints the following error message:
>
> %%%%%%%%%%%%%%%%%%%
> Fatal: ASSERT: "it != mBuffer->mAddedFeatures.end()" in file
> /tmp/buildd/qgis-2.14.2+20trusty/src/core/qgsvectorlayerundocommand.cpp,
> line 255
> Stacktrace (piped through c++filt):
> /usr/bin/qgis.bin[0x40a440]
> /usr/bin/qgis.bin[0x40a548]
> /usr/lib/x86_64-linux-gnu/libQtCore.so.4(qt_message_output(QtMsgType, char
> const*)+0x21)[0x7fd508939bb1]
> /usr/lib/x86_64-linux-gnu/libQtCore.so.4(+0x70ff9)[0x7fd508939ff9]
> /usr/lib/x86_64-linux-gnu/libQtCore.so.4(qFatal(char const*,
> ...)+0x94)[0x7fd50893a804]
>
> /usr/lib/libqgis_core.so.2.14.2(QgsVectorLayerUndoCommandChangeAttribute::undo()+0x659)[0x7fd5092e2c09]
>
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(QUndoCommand::undo()+0x50)[0x7fd5084144e0]
>
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(QUndoStack::setIndex(int)+0xc8)[0x7fd508414e58]
>
> /usr/lib/libqgis_core.so.2.14.2(QgsVectorLayerEditBuffer::rollBack()+0x23)[0x7fd5092c4d43]
>
> /usr/lib/libqgis_core.so.2.14.2(QgsVectorLayer::rollBack(bool)+0x46)[0x7fd5092b81e6]
> /usr/lib/libqgis_app.so.2.14.2(QgisApp::toggleEditing(QgsMapLayer*,
> bool)+0xb4b)[0x7fd50a1b677b]
> /usr/lib/libqgis_app.so.2.14.2(+0x478d41)[0x7fd50a4edd41]
> /usr/lib/x86_64-linux-gnu/libQtCore.so.4(QMetaObject::activate(QObject*,
> QMetaObject const*, int, void**)+0x2da)[0x7fd508a5a87a]
>
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(QAction::triggered(bool)+0x32)[0x7fd507dd9a62]
>
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(QAction::activate(QAction::ActionEvent)+0x63)[0x7fd507ddb433]
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x57cb02)[0x7fd508192b02]
>
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(QAbstractButton::mouseReleaseEvent(QMouseEvent*)+0x6c)[0x7fd508192c2c]
>
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(QToolButton::mouseReleaseEvent(QMouseEvent*)+0xa)[0x7fd508249a4a]
>
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(QWidget::event(QEvent*)+0xaca)[0x7fd507e2f50a]
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(QApplicationPrivate::notify_helper(QObject*,
> QEvent*)+0x8c)[0x7fd507ddfe2c]
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(QApplication::notify(QObject*,
> QEvent*)+0x3ad)[0x7fd507de65dd]
> /usr/lib/libqgis_core.so.2.14.2(QgsApplication::notify(QObject*,
> QEvent*)+0x5b)[0x7fd509049c8b]
> /usr/lib/x86_64-linux-gnu/libQtCore.so.4(QCoreApplication::notifyInternal(QObject*,
> QEvent*)+0x6d)[0x7fd508a464dd]
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(QApplicationPrivate::sendMouseEvent(QWidget*,
> QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&,
> bool)+0x153)[0x7fd507de5d93]
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x2449cb)[0x7fd507e5a9cb]
>
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(QApplication::x11ProcessEvent(_XEvent*)+0x1559)[0x7fd507e5a269]
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x26bb02)[0x7fd507e81b02]
>
> /lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_context_dispatch+0x254)[0x7fd500ceee04]
> /lib/x86_64-linux-gnu/libglib-2.0.so.0(+0x49048)[0x7fd500cef048]
>
> /lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_context_iteration+0x2c)[0x7fd500cef0ec]
>
> /usr/lib/x86_64-linux-gnu/libQtCore.so.4(QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)+0x71)[0x7fd508a737a1]
> /usr/lib/x86_64-linux-gnu/libQtGui.so.4(+0x26bbb6)[0x7fd507e81bb6]
>
> /usr/lib/x86_64-linux-gnu/libQtCore.so.4(QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)+0x2f)[0x7fd508a450af]
>
> /usr/lib/x86_64-linux-gnu/libQtCore.so.4(QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>)+0x175)[0x7fd508a453a5]
>
> /usr/lib/x86_64-linux-gnu/libQtCore.so.4(QCoreApplication::exec()+0x89)[0x7fd508a4ab79]
> /usr/bin/qgis.bin[0x406fd7]
> /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf5)[0x7fd507358ec5]
> /usr/bin/qgis.bin[0x409d48]
> Aborted
> %%%%%%%%%%%%%%%%%%%
>
>
> I've tested both Shapefiles and SpatiaLite layers, getting the same error.
>
>
> Do you have an idea of what could be happening?
>
> I'm using QGIS v.2.14.2 on a Linux Mint machine.
>
>
> Regards,
>
> Germán
>
> --
> -----------
>    |\__
> (:>__)(
>    |/
> Soluciones Geoinformáticas Libres
> http://geotux.tuxfamily.org/
> http://twitter.com/GeoTux2
> http://about.me/germancarrillo
>
> <http://gis.stackexchange.com/users/4972/germ%c3%a1n-carrillo>
>

-- 
-----------
   |\__
(:>__)(
   |/
Soluciones Geoinformáticas Libres
http://geotux.tuxfamily.org/
http://twitter.com/GeoTux2
http://about.me/germancarrillo

<http://gis.stackexchange.com/users/4972/germ%c3%a1n-carrillo>
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