Delete plugins when their corresponding objects are deleted, if their instance belonged the object.

Fixes #2061.

PiperOrigin-RevId: 676402701
Change-Id: Ia4807d57a3763e2100702b7e7ec96c300d0a9cfb

src/user/user_mesh.cc

@@ -269,6 +269,9 @@ void mjCMesh::CopyFromSpec() {
 mjCMesh::~mjCMesh() {
   if (center_) mju_free(center_);
   if (graph_) mju_free(graph_);
+  if (spec.plugin.active && spec.plugin.instance_name->empty()) {
+    model->DeleteElement(spec.plugin.instance);
+  }
 }
 
 

src/user/user_model.cc

@@ -516,6 +516,7 @@ void mjCModel::DeleteElement(mjsElement* el) {
   }
 
   if (compiled) {
+    ResetTreeLists();  // in case of a nested delete
     MakeLists(world);
     ProcessLists(/*checkrepeat=*/false);
   }
@@ -586,6 +587,9 @@ void mjCModel::CopyFromSpec() {
 
 // destructor
 mjCModel::~mjCModel() {
+  // do not rebuild lists if we are in the process of deleting the model
+  compiled = false;
+
   // delete kinematic tree and all objects allocated in it
   delete bodies_[0];
 

src/user/user_objects.cc

@@ -984,6 +984,10 @@ mjCBody::~mjCBody() {
   sites.clear();
   cameras.clear();
   lights.clear();
+
+  if (spec.plugin.active && spec.plugin.instance_name->empty()) {
+    model->DeleteElement(spec.plugin.instance);
+  }
 }
 
 
@@ -2107,6 +2111,14 @@ mjCGeom::mjCGeom(const mjCGeom& other) {
 
 
 
+mjCGeom::~mjCGeom() {
+  if (spec.plugin.active && spec.plugin.instance_name->empty()) {
+    model->DeleteElement(spec.plugin.instance);
+  }
+}
+
+
+
 mjCGeom& mjCGeom::operator=(const mjCGeom& other) {
   if (this != &other) {
     this->spec = other.spec;
@@ -5521,6 +5533,14 @@ mjCActuator::mjCActuator(const mjCActuator& other) {
 
 
 
+mjCActuator::~mjCActuator() {
+  if (spec.plugin.active && spec.plugin.instance_name->empty()) {
+    model->DeleteElement(spec.plugin.instance);
+  }
+}
+
+
+
 mjCActuator& mjCActuator::operator=(const mjCActuator& other) {
   if (this != &other) {
     this->spec = other.spec;
@@ -5875,6 +5895,14 @@ mjCSensor::mjCSensor(const mjCSensor& other) {
 
 
 
+mjCSensor::~mjCSensor() {
+  if (spec.plugin.active && spec.plugin.instance_name->empty()) {
+    model->DeleteElement(spec.plugin.instance);
+  }
+}
+
+
+
 mjCSensor& mjCSensor::operator=(const mjCSensor& other) {
   if (this != &other) {
     this->spec = other.spec;

src/user/user_objects.h

@@ -511,6 +511,7 @@ class mjCGeom : public mjCGeom_, private mjsGeom {
   mjCGeom(mjCModel* = nullptr, mjCDef* = nullptr);
   mjCGeom(const mjCGeom& other);
   mjCGeom& operator=(const mjCGeom& other);
+  ~mjCGeom();
 
   using mjCBase::name;
   mjsGeom spec;                       // variables set by user
@@ -1456,6 +1457,7 @@ class mjCActuator : public mjCActuator_, private mjsActuator {
   mjCActuator(mjCModel* = nullptr, mjCDef* = nullptr);
   mjCActuator(const mjCActuator& other);
   mjCActuator& operator=(const mjCActuator& other);
+  ~mjCActuator();
 
   mjsActuator spec;
   using mjCBase::name;
@@ -1516,6 +1518,7 @@ class mjCSensor : public mjCSensor_, private mjsSensor {
   mjCSensor(mjCModel*);
   mjCSensor(const mjCSensor& other);
   mjCSensor& operator=(const mjCSensor& other);
+  ~mjCSensor();
 
   mjsSensor spec;
   using mjCBase::name;