Limit disconnection scope when switching active vehicle - don't disconnect PlanMapItems (#9757)

* limit disconnection scope

* add test

* review comment

* review comments

src/FlightDisplay/FlyViewMap.qml

@@ -286,7 +286,7 @@ FlightMap {
         PlanMapItems {
             map:                    _root
             largeMapView:           !pipMode
-            planMasterController:   _planMasterController
+            planMasterController:   masterController
             vehicle:                _vehicle
 
             property var _vehicle: object

src/MissionManager/PlanMasterController.cc

@@ -127,9 +127,9 @@ void PlanMasterController::_activeVehicleChanged(Vehicle* activeVehicle)
 
     if (_managerVehicle) {
         // Disconnect old vehicle. Be careful of wildcarding disconnect too much since _managerVehicle may equal _controllerVehicle
-        disconnect(_managerVehicle->missionManager(),       nullptr, nullptr, nullptr);
-        disconnect(_managerVehicle->geoFenceManager(),      nullptr, nullptr, nullptr);
-        disconnect(_managerVehicle->rallyPointManager(),    nullptr, nullptr, nullptr);
+        disconnect(_managerVehicle->missionManager(),       nullptr, this, nullptr);
+        disconnect(_managerVehicle->geoFenceManager(),      nullptr, this, nullptr);
+        disconnect(_managerVehicle->rallyPointManager(),    nullptr, this, nullptr);
     }
 
     bool newOffline = false;

src/MissionManager/PlanMasterControllerTest.cc

@@ -15,11 +15,12 @@
 #include "QGCApplication.h"
 #include "SettingsManager.h"
 #include "AppSettings.h"
+#include "MultiSignalSpyV2.h"
 
 PlanMasterControllerTest::PlanMasterControllerTest(void)
     : _masterController(nullptr)
 {
-    
+
 }
 
 void PlanMasterControllerTest::init(void)
@@ -50,3 +51,33 @@ void PlanMasterControllerTest::_testMissionPlannerFileLoad(void)
     _masterController->loadFromFile(":/unittest/MissionPlanner.waypoints");
     QCOMPARE(_masterController->missionController()->visualItems()->count(), 6);
 }
+
+void PlanMasterControllerTest::_testActiveVehicleChanged(void) {
+    // There was a defect where the PlanMasterController would, upon a new active vehicle,
+    // overzelously disconnect all subscribers interested in the outgoing active vechicle.
+    Vehicle* outgoingManagerVehicle = _masterController->managerVehicle();
+
+    // spyMissionManager emulates a subscriber that should not be disconnected when
+    // the active vehicle changes
+    MultiSignalSpyV2 spyMissionManager;
+    spyMissionManager.init(outgoingManagerVehicle->missionManager());
+    MultiSignalSpyV2 spyMasterController;
+    spyMasterController.init(_masterController);
+
+    // Since MissionManager works with actual vehicles (which we don't have in the test cycle)
+    // we have to be a bit creative emulating a signal emitted by a MissionManager.
+    emit outgoingManagerVehicle->missionManager()->error(0,"");
+    auto missionManagerErrorSignalMask = spyMissionManager.signalNameToMask("error");
+    QVERIFY(spyMissionManager.checkOnlySignalByMask(missionManagerErrorSignalMask));
+    spyMissionManager.clearSignal("error");
+    QVERIFY(spyMissionManager.checkNoSignals());
+
+    _connectMockLink(MAV_AUTOPILOT_PX4);
+    auto masterControllerMgrVehicleChanged = spyMasterController.signalNameToMask("managerVehicleChanged");
+    QVERIFY(spyMasterController.checkSignalByMask(masterControllerMgrVehicleChanged));
+
+    emit outgoingManagerVehicle->missionManager()->error(0,"");
+    // This signal was affected by the defect - it wouldn't reach the subscriber. Here
+    // we make sure it does.
+    QVERIFY(spyMissionManager.checkOnlySignalByMask(missionManagerErrorSignalMask));
+}

src/MissionManager/PlanMasterControllerTest.h

@@ -23,7 +23,7 @@
 class PlanMasterControllerTest : public UnitTest
 {
     Q_OBJECT
-    
+
 public:
     PlanMasterControllerTest(void);
 
@@ -33,6 +33,7 @@ private slots:
 
     void _testMissionFileLoad(void);
     void _testMissionPlannerFileLoad(void);
+    void _testActiveVehicleChanged(void);
 
 private:
     PlanMasterController*   _masterController;