ae7a0ddea4
Qt Quick requires third-party rendering codes to follow its standards with regards to viewport transform. Qt 5.6 adds a 'mirrorVertically' property but that only solves the solution for that version of Qt onwards. Telling Mapbox GL core to flip the Y axis makes QQuickMapboxGL item available for Qt 5.2 onwards. Qt 'mirrorVertically' property documentation: http://doc.qt.io/qt-5/qquickframebufferobject.html#mirrorVertically-prop Fixes #4866.