With the code
the window will not become full screen when unminimized on Windows, or rather that will not be the state the QWidget::windowState() returns after being unminimized. If QWindowsWindowFunctions::setHasBorderInFullScreen() is not used, it works as expected.
A more elaborate example that demonstrates the issue is attached as fullscreen.cc.
|For Gerrit Dashboard: QTBUG-61595|
|198382,2||Windows QPA: Take hasBorderInFullScreen into account when checking for fullscreen||5.9||qt/qtbase||Status: MERGED||+2||0|