Fix a bug in MuJoCo's user_mesh.cc that caused meshdir_ to be overwritten when a model was loaded with a nested model.

PiperOrigin-RevId: 675092713
Change-Id: Iad6336141749510bf5544cab9c06533ee1589c08

src/user/user_mesh.cc

@@ -222,8 +222,12 @@ void mjCMesh::PointToLocal() {
 
 void mjCMesh::NameSpace(const mjCModel* m) {
   mjCBase::NameSpace(m);
-  modelfiledir_ = FilePath(m->spec_modelfiledir_);
-  meshdir_ = FilePath(m->spec_meshdir_);
+  if (modelfiledir_.empty()) {
+    modelfiledir_ = FilePath(m->spec_modelfiledir_);
+  }
+  if (meshdir_.empty()) {
+    meshdir_ = FilePath(m->spec_meshdir_);
+  }
 }
 
 
@@ -2034,8 +2038,12 @@ void mjCSkin::NameSpace(const mjCModel* m) {
   for (auto& name : spec_bodyname_) {
     name = m->prefix + name + m->suffix;
   }
-  modelfiledir_ = FilePath(m->spec_modelfiledir_);
-  meshdir_ = FilePath(m->spec_meshdir_);
+  if (modelfiledir_.empty()) {
+    modelfiledir_ = FilePath(m->spec_modelfiledir_);
+  }
+  if (meshdir_.empty()) {
+    meshdir_ = FilePath(m->spec_meshdir_);
+  }
 }
 
 

src/user/user_model.cc

@@ -607,6 +607,7 @@ mjCModel::~mjCModel() {
   for (int i=0; i<tuples_.size(); i++) delete tuples_[i];
   for (int i=0; i<keys_.size(); i++) delete keys_[i];
   for (int i=0; i<defaults_.size(); i++) delete defaults_[i];
+  for (int i=0; i<specs_.size(); i++) mj_deleteSpec(specs_[i]);
 
   if (plugin_owner) {
     for (int i=0; i<plugins_.size(); i++) delete plugins_[i];

src/user/user_objects.cc

@@ -3405,8 +3405,12 @@ void mjCHField::CopyFromSpec() {
 
 void mjCHField::NameSpace(const mjCModel* m) {
   mjCBase::NameSpace(m);
-  modelfiledir_ = FilePath(m->spec_modelfiledir_);
-  meshdir_ = FilePath(m->spec_meshdir_);
+  if (modelfiledir_.empty()) {
+    modelfiledir_ = FilePath(m->spec_modelfiledir_);
+  }
+  if (meshdir_.empty()) {
+    meshdir_ = FilePath(m->spec_meshdir_);
+  }
 }
 
 
@@ -3650,8 +3654,12 @@ void mjCTexture::CopyFromSpec() {
 
 void mjCTexture::NameSpace(const mjCModel* m) {
   mjCBase::NameSpace(m);
-  modelfiledir_ = FilePath(m->spec_modelfiledir_);
-  texturedir_ = FilePath(m->spec_texturedir_);
+  if (modelfiledir_.empty()) {
+    modelfiledir_ = FilePath(m->spec_modelfiledir_);
+  }
+  if (texturedir_.empty()) {
+    texturedir_ = FilePath(m->spec_texturedir_);
+  }
 }
 
 

src/xml/xml_native_reader.cc

@@ -3645,7 +3645,6 @@ void mjXReader::Body(XMLElement* section, mjsBody* body, mjsFrame* frame,
           throw mjXError(0, "could not find body '%s''%s'", body_name.c_str());
         }
         if (mjs_attachBody(pframe, child, prefix.c_str(), "") != 0) {
-          mj_deleteSpec(asset);
           throw mjXError(elem, mjs_getError(spec));
         }
       } else {