Crash on project open when mapcanvas extents = nan

[signature-story]

If somehow a project's mapcanvas extents are all erroneously set to nan, then when that project is opened QGIS 3.10.2 will crash. Opening the qgs file in a text editor and changing the extents to realistic numbers will allow the project to be opened and subsequently saved and reopened without issue. But without the user savvy to edit the qgs file, there is no way to recover the project.

Reproduce by creating a new project and then saving as a qgs file. Open that qgs file in a text editor and change all mapcanvas extents to nan like this:
<mapcanvas name="theMapCanvas" annotationsVisible="1"> <units>feet</units> <extent> <xmin>nan</xmin> <ymin>nan</ymin> <xmax>nan</xmax> <ymax>nan</ymax> </extent>

Save the file and then try to open it in QGIS. It will crash.

Then open in a text editor and correct the mapcanvas extents to anything realistic. For example:
<mapcanvas name="theMapCanvas" annotationsVisible="1"> <units>feet</units> <extent> <xmin>0</xmin> <ymin>0</ymin> <xmax>1</xmax> <ymax>1</ymax> </extent>

Save the changes, and you should now be able to open the project in QGIS.

A separate issue is how the extents were erroneously set to nan in the first place. That's more difficult for me to verify and report, but basically it occurred when I tried to zoom to view a feature. That feature may have had bad geometries. Not sure. But it locked the viewing area and would not let me pan or zoom. I was able to exit the project, but when re-opening it would crash. Eventually discovered in the extents set to nan in the project file. If I figure out how to reproduce consistently I'll post a separate report with shapefiles.

QGIS version
3.10.2-A Coruña
QGIS code revision
d4cd3cf
Compiled against Qt
5.11.2
Running against Qt
5.11.2
Compiled against GDAL/OGR
3.0.3
Running against GDAL/OGR
3.0.3
Compiled against GEOS
3.8.0-CAPI-1.13.1
Running against GEOS
3.8.0-CAPI-1.13.1
Compiled against SQLite
3.29.0
Running against SQLite
3.29.0
PostgreSQL Client Version
11.5
SpatiaLite Version
4.3.0
QWT Version
6.1.3
QScintilla2 Version
2.10.8
Compiled against PROJ
6.3.0
Running against PROJ
Rel. 6.3.0, January 1st, 2020
OS Version
Windows 7 SP 1 (6.1)
Active python plugins
LAStools;
profiletool;
shapetools;
db_manager;
MetaSearch;
processing

[elpaso]

@signature-story can you attach a crashing project? I tried to replace extent with nan on one o my test projects but it didn't crash.

[signature-story]

Zipped qgs file attached. Crashes for me every time. I created it using the steps outlined in the original post: editing new qgs file in text editor to replace extents with nan.

iCrash.zip

[roya0045]

@signature-story if you update your qgis is the crash still occuring?

[signature-story]

yes after updating to 3.10.5 the crashes continue to occur.

[pblottiere]

I succeeded in opening the iCrash.qgs project with QGIS master. No crash here on Archlinux.

[Pedro-Murteira]

@signature-story I'm not being able to reproduce this issue on QGIS 3.22.5 and 3.24.1. Can you still reproduce the issue in more recent releases?

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[github-actions]

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