[Bugfix]Gui: in draggers, remove/detach all callbacks + add checks an…

…d asserts, hopefully fixes FreeCAD#9465

src/Gui/SoFCCSysDragger.cpp

@@ -130,6 +130,11 @@ TDragger::~TDragger()
 {
  fieldSensor.setData(nullptr);
  fieldSensor.detach();
+
+ this->removeStartCallback(&TDragger::startCB);
+ this->removeMotionCallback(&TDragger::motionCB);
+ this->removeFinishCallback(&TDragger::finishCB);
+ removeValueChangedCallback(&TDragger::valueChangedCB);
 }
 
 void TDragger::buildFirstInstance()
@@ -198,18 +203,21 @@ SoGroup* TDragger::buildGeometry()
 void TDragger::startCB(void *, SoDragger *d)
 {
  auto sudoThis = static_cast<TDragger *>(d);
+ assert(sudoThis);
  sudoThis->dragStart();
 }
 
 void TDragger::motionCB(void *, SoDragger *d)
 {
  auto sudoThis = static_cast<TDragger *>(d);
+ assert(sudoThis);
  sudoThis->drag();
 }
 
 void TDragger::finishCB(void *, SoDragger *d)
 {
  auto sudoThis = static_cast<TDragger *>(d);
+ assert(sudoThis);
  sudoThis->dragFinish();
 }
 
@@ -408,6 +416,11 @@ RDragger::~RDragger()
 {
  fieldSensor.setData(nullptr);
  fieldSensor.detach();
+
+ this->removeStartCallback(&RDragger::startCB);
+ this->removeMotionCallback(&RDragger::motionCB);
+ this->removeFinishCallback(&RDragger::finishCB);
+ removeValueChangedCallback(&RDragger::valueChangedCB);
 }
 
 void RDragger::buildFirstInstance()
@@ -474,18 +487,21 @@ SoGroup* RDragger::buildGeometry()
 void RDragger::startCB(void *, SoDragger *d)
 {
  auto sudoThis = static_cast<RDragger *>(d);
+ assert(sudoThis);
  sudoThis->dragStart();
 }
 
 void RDragger::motionCB(void *, SoDragger *d)
 {
  auto sudoThis = static_cast<RDragger *>(d);
+ assert(sudoThis);
  sudoThis->drag();
 }
 
 void RDragger::finishCB(void *, SoDragger *d)
 {
  auto sudoThis = static_cast<RDragger *>(d);
+ assert(sudoThis);
  sudoThis->dragFinish();
 }
 
@@ -820,6 +836,17 @@ SoFCCSysDragger::SoFCCSysDragger()
 
 SoFCCSysDragger::~SoFCCSysDragger()
 {
+ translationSensor.setData(nullptr);
+ translationSensor.detach();
+ rotationSensor.setData(nullptr);
+ rotationSensor.detach();
+ cameraSensor.setData(nullptr);
+ cameraSensor.detach();
+ idleSensor.setData(nullptr);
+ idleSensor.unschedule();
+
+ removeValueChangedCallback(&SoFCCSysDragger::valueChangedCB);
+ removeFinishCallback(&SoFCCSysDragger::finishDragCB);
 }
 
 
@@ -877,6 +904,8 @@ SbBool SoFCCSysDragger::setUpConnections(SbBool onoff, SbBool doitalways)
 void SoFCCSysDragger::translationSensorCB(void *f, SoSensor *)
 {
  auto sudoThis = static_cast<SoFCCSysDragger *>(f);
+ if(!f)
+ return;
 
  SbMatrix matrix = sudoThis->getMotionMatrix(); // clazy:exclude=rule-of-two-soft
  sudoThis->workFieldsIntoTransform(matrix);
@@ -886,6 +915,8 @@ void SoFCCSysDragger::translationSensorCB(void *f, SoSensor *)
 void SoFCCSysDragger::rotationSensorCB(void *f, SoSensor *)
 {
  auto sudoThis = static_cast<SoFCCSysDragger *>(f);
+ if(!f)
+ return;
 
  SbMatrix matrix = sudoThis->getMotionMatrix(); // clazy:exclude=rule-of-two-soft
  sudoThis->workFieldsIntoTransform(matrix);
@@ -944,6 +975,8 @@ void SoFCCSysDragger::setUpAutoScale(SoCamera *cameraIn)
 void SoFCCSysDragger::cameraCB(void *data, SoSensor *)
 {
  auto sudoThis = static_cast<SoFCCSysDragger *>(data);
+ if (!sudoThis)
+ return;
  if (!sudoThis->idleSensor.isScheduled())
  sudoThis->idleSensor.schedule();
 }
@@ -989,6 +1022,8 @@ void SoFCCSysDragger::handleEvent(SoHandleEventAction * action)
 void SoFCCSysDragger::idleCB(void *data, SoSensor *)
 {
  auto sudoThis = static_cast<SoFCCSysDragger *>(data);
+ if (!data)
+ return;
  SoField* field = sudoThis->cameraSensor.getAttachedField();
  if (field)
  {
@@ -1012,6 +1047,7 @@ void SoFCCSysDragger::idleCB(void *data, SoSensor *)
 void SoFCCSysDragger::finishDragCB(void *data, SoDragger *)
 {
  auto sudoThis = static_cast<SoFCCSysDragger *>(data);
+ assert(sudoThis);
 
  // note: when creating a second view of the document and then closing
  // the first viewer it deletes the camera. However, the attached field