Qt 5.12.6 is a bug-fix release. It maintains both forward and backward compatibility (source and binary) with Qt 5.12.0 through 5.12.5. For more details, refer to the online documentation included in this distribution. The documentation is also available online: https://doc.qt.io/qt-5/index.html The Qt version 5.12 series is binary compatible with the 5.11.x series. Applications compiled for 5.11 will continue to run with 5.12. Some of the changes listed in this file include issue tracking numbers corresponding to tasks in the Qt Bug Tracker: https://bugreports.qt.io/ Each of these identifiers can be entered in the bug tracker to obtain more information about a particular change. **************************************************************************** * Compositor * **************************************************************************** - Fixed various rounding errors related to touch and mouse input. - Fixed a crash when trying to maximize an XdgTopLevel with no output. - Important Behavior Changes: * Fixed potential memory access violation. Between version 5.11 and 5.12 binary compatibility for the wayland compositor module was broken by increasing the size of various classes. This was unfortunately not visible in public headers. As a consequence, application C++ code allocating or subclassing any of the following classes would have potential memory access violations: QWaylandKeymap, QWaylandQuickOutput, QWaylandQuickSurface, QWaylandIviSurface, QWaylandWlShellSurface, QWaylandXdgSurface, QWaylandXdgSurfaceV5, QWaylandXdgPopupV5, QWaylandXdgSurfaceV6. To mitigate this issue, upgrade Qt to 5.12.6 and recompile all compositor code. Do not run a compositor built with 5.11 or earlier against Qt versions 5.12 or later. **************************************************************************** * QPA plugin * **************************************************************************** - Fixed a freeze that happened when starting a drag-and-drop operation without a valid source surface. - Fixed a 100 ms freeze that would occur if applications did not draw after receiving a deliverUpdateRequest(). - Fixed touch point position rounding errors. - Fixed a freeze that could happen when showing a window. - Fixed an issue where touch focus would be set to false before all touch points where released. - Fixed touch event touch points sometimes being reordered, which caused issues with QtQuick's MultiPointTouchArea. - Fixed a crash that happened with very long window titles using UTF-16 characters.