PR: Qt 6: QApplication: Make exec_() a simple alias for exec()

[rear1019]

See commit message for details. The change is required for Spyder to start with PyQt6/PySide6. Instead of changing qtpy, we also could opt for removing the monkey patch of QApplication in Spyder: Spyder seems to work without it (However, mind that I haven’t checked beyond “Spyder starts”).

[1] See https://github.com/spyder-ide/spyder/blob/e624b704959c965ce5a83991f9e374a7759dc6cc/spyder/app/utils.py#L302-L314

[coveralls]

coverage: 96.739% (-0.04%) from 96.781%
when pulling de78b84 on procitec:qt6_simplify_qapp_exec_
into 3238de7 on spyder-ide:master.

[dalthviz]

Hi @rear1019 sorry for such a late response and thank you for your help here! I think the exec_ handling via the helper was added at #422 but if I understand correctly then seems like its use is not needed at least for QApplication and it can cause issues for subclasses, right?

Could it be possible to add a test to check for the QApplication subclassing and exec/exec_ calling case please?

Also, just in case what do you think @ccordoba12 @StSav012 ?

Thanks again for your work here!

[ccordoba12]

This looks good to me, although it's no longer necessary for Spyder.

[StSav012]

@rear1019, thank you for bringing the issue up. I haven't dag deeper than the following paragraph.

Well, the exec method is actually static [QCoreApplication.exec, QGuiApplication.exec, QApplication.exec]. I'm genuinely surprised that no one calls it this way. I don't.

However, in PySide6, QCoreApplication.exec_ (with the underscore) is not static. Report it if you wish to. That's yet another incompatibility between the flavors. I don't have time to add the fix to QtPy until May, probably.

Therefore, I thought that as QCoreApplication.exec are static, the possibly_static_exec is semantically appropriate there.

You're totally right that as the calls are always to the static method there, the possibly_static_exec is excessive there. The PR looks good, although I'd add comments into the code to describe the inconsistency between the exec_ implementations for QApplication, QDialog, and QMenu.

Finally, please, change QGuiApplication.exec and QCoreApplication.exec similarly.

[ccordoba12]

@dalthviz, do you want to address this one for 2.4.2 (according to @rear1019's comments) or leave it for later?

[dalthviz]

Leaving it for 2.4.3 should be fine