[Development] Reverting some patches in qtquickcontrols2 for the 5.12.0 release

[Mitch Curtis]

Hi.

My fixes for https://bugreports.qt.io/browse/QTBUG-67559 have recently introduced a crash in KDE:

https://bugreports.qt.io/browse/QTBUG-71770

Quoting the commit message from my patch that reverts  https://codereview.qt-project.org/#/c/245480/:

"Revert all Menu delegate patches

This reverts the following commits:
d5cb26bc56a3b6f6e99c88654d4f7a65f43551ac - Menu: ensure the correct delegates are used when created via Component
d923dd467c1aeb3e195a09949b04862084002f88 - MenuBar: ensure the correct delegates are used when created via Component
d56c193eb4ceb640611d66f22e1f26aae91cd7d1 - QQuickPopupPositioner: avoid adding duplicate item change listeners
567a2de8cd493aabe0055d6dbc367b39447e70dd - Stabilize tst_qquickmenubar
953fbac6131823e4fce0eb4707a854469c4c04ff - Fix Instantiator-created MenuItems disappearing
936d31179d44220571ded15840bedeccb581c83b - tst_qquickmenu: add a test for MenuItems before and after a Repeater
fc1832810f6c09505d9413685ed0b2d6295bea4a - QQuickMenuBar: fix menu not opening

The fix for QTBUG-67559 has caused lots of issues, with the latest being a
crash right before the 5.12 release. The bug that they fix is a P2,
so it's not worth the hassle. The patches might be able to be resubmitted
to dev after the crash is fixed.

Change-Id: Ic192c7a302176bcdb2503b636b3462b10898a2ba
Fixes: QTBUG-71770"

I believe that the patches are correct in principle, and the crash is probably just an oversight and not a fundamental problem, but I don't want to hold up the release for a P2 that has already required lots of follow-up fixes.

Jani said:

"Ok, but then we should agree if QTBUG-71770 is a blocker or can we release Qt 5.12.0 with it as known issue. It is a crash but if you can't reproduce the issue it sounds like a corner case for me and so on we should be able to keep it as known issue to minimize new risks."

So I thought I'd check here since I haven't gotten any response elsewhere when asking about what to do.

Cheers.