Error after adding second map to Fusion

[andrewd]

Create a Fusion application, then go to "Maps" and add a 2nd map under "Currently Available Maps". The map gets added correctly, but you can't select it. As soon as you select it, you get an error - which means that you can't configure it, or even delete it.

Error is: System.NullReferenceException: Object reference not set to an instance of an object.

at Maestro.Editors.Fusion.MapCtrl..ctor(IApplicationDefinition appDef, IMapGroup group, IEditorService edService, IMapWidget widget) in c:\working\JenkinsCI\home\slave_win\jobs\Maestro trunk\workspace\Maestro.Editors\Fusion\MapCtrl.cs:line 105 at Maestro.Editors.Fusion.MapSettingsCtrl.lstMaps_SelectedIndexChanged(Object sender, EventArgs e) in c:\working\JenkinsCI\home\slave_win\jobs\Maestro trunk\workspace\Maestro.Editors\Fusion\MapSettingsCtrl.cs:line 119 at System.Windows.Forms.ListView.OnSelectedIndexChanged(EventArgs e) at System.Windows.Forms.ListView.WmReflectNotify(Message& m) at System.Windows.Forms.ListView.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

[jng]

In 9115:

Fix NRE. We should be setting the id from the MapGroup and not the associated MapWidget that is null if it doesn't point to this MapGroup id

Fixes #2507