As part of df359bcb70 the semantics and
interaction between QEventLoopLocker and QGuiApplication was changed,
based on the assumption that these two mechanisms were independent
and should not affect each other.
This had a surprising regression where the use of QEventLoopLocker in
combination with the QCoreApplication::isQuitLockEnabled() automatic
quit would end up quitting the app, even if it had open windows, for
example when the last job of some internal job queue finished.
It could be argued that if the app has open windows that should not
be closed, they should ignore the Close event, and that an application
with running QEventLoopLocker jobs should maintain an active window
showing the progress of those jobs, but still, this is regression
that we want to fix.
We now bail out if !lastWindowClosed() in QGuiApplication's
canQuitAutomatically, which is triggered from QEventLoopLocker's
isQuitLockEnabled() behavior. And we do so regardless of whether
quitOnLastWindowClosed is set or not, as the latter property
determines the behavior when closing a window, not the behavior
when a QEventLoopLocker goes out of scope.
Similarly, we now block quitting of the application when triggered
by quitOnLastWindowClosed() if a QEventLoop is active, regardless of
the isQuitLockEnabled(), as the latter property is determining
whether we should trigger a quit, not whether we should block them.
[ChangeLog][Important behavior changes] Fixed a regression where
the last QEventLoopLocker going out of scope would quit the app,
even if there were open windows, if quitOnLastWindowClosed was
false.
[ChangeLog][Important behavior changes] Fixed a regression where
closing the last window would quit the app, even if there were
active QEventLoopLockers, if isQuitLockEnabled was false.
Fixes: QTBUG-124386
Pick-to: 6.7 6.5
Change-Id: I84fd0ddea78a2f417f3a17b326113c880079cf85
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
0b494c47d3