This reverts commit 99c8ffb9f2. It fixed
QTBUG-104201, which in essence pointed out a state mismatch between
widgets and platform windows on Linux (X11 and wayland). Mismatches
occurred in the margins between calls to QWidget and async screen
rendering: While the widget layer reported the expected size, the
platform layer did so only after the rendering thread had finished.
As mentioned in the comments of QTBUG-104201, the state mismatch is
predictable, temporary and consistent.
By bridging the time gab, an async operation was made to look
synchronous. That gave more comfort to application developers. By
oversight, it broke code that relied on the platform window state
reflecting physical rendering. This has caused QTBUG-126479 as a
regression.
Both purposes can't be served at the same time: The platform window
state either reflects rendering, or the expected state. It's therefore
justified to revert.
Reason for revert: <Causes QTBUG-126479>
Pick-to: 6.7 6.5
Fixes: QTBUG-126479
Task-number: QTBUG-104201
Change-Id: I22380a6a463822a1cb4be90a44d2775954c7ca82
Reviewed-by: Liang Qi <liang.qi@qt.io>
(cherry picked from commit 7d7be38d95eb82ef3e0be5250440072d8b5bc4b2)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
678dccb7ac