The 'isReady' boolean flag is now set to 'true' only
once the Component.onCompleted slot is reached.
The flag is then used as a safe-guard in the
onZoomLevelChanged slot. Calculate the small circle radius
(mapHelper.calculateSmallCircleRadius()) only if 'isReady'
is set to true.
Prevents a crash if the Map widget is not ready, yet a zoom
level is set via the 'zoomLevel' property. The crash happens
because mapHelper.calculateSmallCircleRadius() has a callback
to the Map component to estimate some points and distances of the
small circle.
Reported-by: Stefan Fuchs <sfuchs@gmx.de>
Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>