[Bug]: error 500 when activating the table attribute feature for a layer that comes from another QGIS project (embed layers)

[arno974]

What is the bug?

Activating the table attribute feature for a layer that comes from another QGIS project (embed layers) generates an error 500 with the error :
[0] count(): Argument #1 ($value) must be of type Countable|array, null given /media/arnaud/perso/www/lizmap/lizmap/modules/lizmap/lib/Project/QgisProject.php 1033

If I remove this layer from the attribute table list feature the error 500 disappear.

Steps to reproduce the issue

1- In QGIS Lizmap Plugin activate attribute table for an embed layer
2- In QGIS Web reload the project -> error 500

Versions

• Lizmap Web Client : 3.5.7
• Lizmap plugin : 3.9.2
• QGIS Desktop : 3.16.16
• QGIS Server and plugins unknown status because no admin login provided

Check Lizmap plugin

• I have done the step just before in the Lizmap QGIS desktop plugin before opening this ticket. Otherwise, my ticket is not considered valid and might get closed.

QGIS server version, only if the section above doesn't mention the QGIS Server version

3.16.6

Operating system

Ubuntu 22.04

Browsers

Firefox

Browsers version

106.0.2

Relevant log output

[0]	count(): Argument #1 ($value) must be of type Countable|array, null given	/media/arnaud/perso/www/lizmap/lizmap/modules/lizmap/lib/Project/QgisProject.php	1033

[nworr]

is the php version > 8 and in this case can you test with lower version php (7.4) ?

[arno974]

PHP Version PHP 8.1.2-1ubuntu2.8 (cli)
Unfortunately I can't test with a 7.4 php version as it is not available in my packages.

[nworr]

can reproduce with #3334
end2end provided test fail (page in error while loading a project with embed layer)