QGIS crashes while calling readLayerXml() on a WMS layer on Windows

[cxcandid]

What is the bug or the crash?

QGIS crashes while calling readLayerXml() on Windows.

Steps to reproduce the issue

Try the following code, which is part of the changeDataSource plugin, to reproduce the bug:

rasterLayer ... active WMS raster layer

from PyQt5.QtXml import *

rasterLayer = iface.activeLayer()

XMLDocument = QDomDocument("style")
XMLMapLayers = XMLDocument.createElement("maplayers")
XMLMapLayer = XMLDocument.createElement("maplayer")
context = QgsReadWriteContext()
rasterLayer.writeLayerXml(XMLMapLayer,XMLDocument, context)

#   XMLMapLayer.firstChildElement("datasource").firstChild().setNodeValue(newDatasource)
#   XMLMapLayer.firstChildElement("provider").firstChild().setNodeValue(newProvider)

XMLMapLayers.appendChild(XMLMapLayer)
XMLDocument.appendChild(XMLMapLayers)
rasterLayer.readLayerXml(XMLMapLayer, context) # <== QGIS crashes here

Versions

QGIS version
3.22.2-Białowieża
QGIS code revision
1601ec4
Qt version
5.15.2
Python version
3.9.5
GDAL/OGR version
3.4.0
PROJ version
8.2.0
EPSG Registry database version
v10.038 (2021-10-21)
GEOS version
3.10.0-CAPI-1.16.0
SQLite version
3.35.2
PDAL version
2.3.0
PostgreSQL client version
13.0
SpatiaLite version
5.0.1
QWT version
6.1.3
QScintilla2 version
2.11.5
OS version
Windows 10 Version 2009

Active Python plugins
db_manager
0.1.20
grassprovider
2.12.99
MetaSearch
0.3.5
processing
2.12.99
sagaprovider
2.12.99

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

Crash ID: cabb170ce9b4cbfc835aad0515873f11dc7a8376

Stack Trace

QgsDefaultRasterLayerLegend::createLayerTreeModelLegendNodes :
QgsLayerTreeModel::addLegendToLayer :
QgsLayerTreeModel::refreshLayerLegend :
QgsLayerTreeModel::layerLegendChanged :
QObject::qt_static_metacall :
QObject::qt_static_metacall :
QObject::qt_static_metacall :
QgsRasterLayer::setRendererForDrawingStyle :
QgsRasterLayer::setDataProvider :
QgsRasterLayer::readXml :
QgsMapLayer::readLayerXml :
PyInit__core :
PyArg_ParseTuple_SizeT :
PyEval_EvalFrameDefault :
PyObject_GC_Del :
PyEval_EvalCodeWithName :
PyEval_EvalCodeEx :
PyEval_EvalCode :
PyEval_GetBuiltins :
PyEval_GetBuiltins :
PyEval_EvalFrameDefault :
PyFloat_FromDouble :
PyEval_EvalFrameDefault :
PyObject_GC_Del :
PyFloat_FromDouble :
PyEval_EvalFrameDefault :
PyObject_GC_Del :
PyFloat_FromDouble :
PyEval_EvalFrameDefault :
PyFloat_FromDouble :
PyEval_EvalFrameDefault :
PyFloat_FromDouble :
PyEval_EvalFrameDefault :
PyFunction_Vectorcall :
PyFloat_FromDouble :
PyVectorcall_Call :
PyObject_Call :
PyInit__gui :
QWidget::event :
QFrame::event :
QAbstractScrollArea::event :
PyInit__gui :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QSizePolicy::QSizePolicy :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QGuiApplicationPrivate::processKeyEvent :
QWindowSystemInterface::sendWindowSystemEvents :
QEventDispatcherWin32::processEvents :
qt_plugin_query_metadata :
QEventLoop::exec :
QCoreApplication::exec :
main :
BaseThreadInitThunk :
RtlUserThreadStart :

QGIS Info
QGIS Version: 3.22.2-Bia?owie?a
QGIS code revision: 1601ec4
Compiled against Qt: 5.15.2
Running against Qt: 5.15.2
Compiled against GDAL: 3.4.0
Running against GDAL: 3.4.0

System Info
CPU Type: x86_64
Kernel Type: winnt
Kernel Version: 10.0.19043

[roya0045]

The title and descriptions mentions the crash on write but the code snippets mentions a crash on read. Also is there a stacktrace or anything more?

[cxcandid]

@roya0045 this was a mistake, should be readLayerXml() of course.
BTW: the code is taken from changeDataSource plugin, which fails in QGIS 3.22.2 as well.
In QGIS 3.20.3 everything is fine. I can add a stack trace, but I guess it won't be of much help.

[cxcandid]

@roya0045 in case it might be helpful after all, I added the stack trace to the original report.

[cxcandid]

QGIS still crashes in 3.22.3 while trying to change a raster datasource with changeDataSource plugin.

[elpaso]

Cannot reproduce on linux/master.

[cxcandid]

I installed QGIS 3.22.3 on a brand new Lenovo Notebook with Windows 10 Home (20H2) and received the same crash.
Can someone please confirm this QGIS 3.22.x bug on Windows?

BTW: I'm using OSGeo4W installer

[github-actions]

The QGIS project highly values your report and would love to see it addressed. However, this issue has been left in feedback mode for the last 14 days and is being automatically marked as "stale".
If you would like to continue with this issue, please provide any missing information or answer any open questions. If you could resolve the issue yourself meanwhile, please leave a note for future readers with the same problem and close the issue.
In case you should have any uncertainty, please leave a comment and we will be happy to help you proceed with this issue.
If there is no further activity on this issue, it will be closed in a week.

[cxcandid]

This issue still exists in QGIS 3.24.0 (Windows 10).
QGIS throws "Windows fatal exception: access violation".

[gioman]

This issue still exists in QGIS 3.24.0 (Windows 10).

@cxcandid no crash here (master, Win10) with the code you provided.

[cxcandid]

QGIS crashes if raster layer source is WMS or XYZ. With file based images it's ok.

[gioman]

QGIS crashes if raster layer source is WMS or XYZ

Confirmed.

[cxcandid]

Issue is solved in QGIS 3.24.1 Rev. 5709b82.

Thanks a lot!