QGCCorePlugin is currently constructed with a QGCToolbox* toolbx parameter of null. This is because at the time QGCCorePlugin (or an actual custom plugin) is constructed app->toolbox() is null.
_scanAndLoadPlugins() is called as part of the QGCToolbox constructor where all toolbox classes use the same format:
_class = new Class(app, this);

The creation of QGCCorePlugin should follow the same pattern.

The practical issue I had with this is that because the parent is not set correctly, QGCCorePlugin is not destructed when the app is closed. This means any code in the destructor is not run. (QGCCorePlugin itself has as a destructor which is currently not being called).

Plan: New wizard done model

New wizard done model

Plan FW Landing: Drag of land/loiter maintains land distance/heading as appropriate

Drag of land/loiter maintains land distance/heading as appropriate

WP index to the values widget

Plan: Output Survey polygons with KML save

Fix return value

Out Survey polygons with KML save

Remove deprecated QTime::start function and use QELapsedTimer

Add support for chunked STATUSTEXT

Remove unused HIL code

Stable update

Stable update

Plan: Fix hamburger positioning

Removed unnecessary memory allocation

Update mavlink submodule

Add support for chunked STATUSTEXT

Removed unused variable

Removed compile warnings on Linux

Remove unused HIL code

Fix hamburger positioning

remove trailing whitespaces in JoystickManager.cc

Add UVify Core in the firmware downloader.

Update GPS struct name to match PX4

Removed unreachable code

Emit sensorHilChanged signal only if it was really changed

Removed checking pointer after 'new' operator

Much better conversion of Mission to KML for use as 3d validation

Much better mission->kml conversion support

Use global palette

Add support for isTakeoffCommand MissionCommandUIInfo