Guard QTabBar against nested event processing during moving tabs
requested to merge asturmlechner/qtbase:asturmlechner/QTBUG-74478-mouse-flicking-on-qtabwidget-segfault into kde/5.15
If moving tabs results in nested event processing by the user's code in response to the tab index changing, the mouse release event might have been processed already, and the pressed index is reset back to -1.
Pick-to: 6.5 6.2 5.15 Fixes: QTBUG-74478 Change-Id: I9696b10a6218456ab381ffe3a65ea471cfa42413 Reviewed-by: Richard Moe Gustavsen richard.gustavsen@qt.io (cherry picked from commit 6736118b)