Prevent uninitialized memory during a copy of joints and actuators.

PiperOrigin-RevId: 653340718
Change-Id: Icc5ada05abd590504c157311a309f9b8493feac9

src/user/user_objects.h

@@ -385,6 +385,12 @@ class mjCJoint_ : public mjCBase {
  protected:
   mjCBody* body;                   // joint's body
 
+  // variable used for temporarily storing the state of the joint
+  int qposadr_;                    // address of dof in data->qpos
+  int dofadr_;                     // address of dof in data->qvel
+  mjtNum qpos[7];                  // qpos at the previous step
+  mjtNum qvel[6];                  // qvel at the previous step
+
   // variable-size data
   std::vector<double> userdata_;
   std::vector<double> spec_userdata_;
@@ -420,11 +426,6 @@ class mjCJoint : public mjCJoint_, private mjsJoint {
  private:
   int Compile(void);               // compiler; return dofnum
   void PointToLocal(void);
-
-  int qposadr_;                    // address of dof in data->qpos
-  int dofadr_;                     // address of dof in data->qvel
-  mjtNum qpos[7];                  // qpos at the previous step
-  mjtNum qvel[6];                  // qvel at the previous step
 };
 
 
@@ -1362,6 +1363,11 @@ class mjCActuator_ : public mjCBase {
  protected:
   int trnid[2];                   // id of transmission target
 
+  // variable used for temporarily storing the state of the actuator
+  int actadr_;              // address of dof in data->act
+  int actnum_;              // number of dofs in data->act
+  std::vector<mjtNum> act;  // act at the previous step
+
   // variable-size data
   std::string plugin_name;
   std::string plugin_instance_name;
@@ -1407,10 +1413,6 @@ class mjCActuator : public mjCActuator_, private mjsActuator {
   void NameSpace(const mjCModel* m);
 
   mjCBase* ptarget;  // transmission target
-
-  int actadr_;              // address of dof in data->act
-  int actnum_;              // number of dofs in data->act
-  std::vector<mjtNum> act;  // act at the previous step
 };