From 75f196c7efd8a2637437b35492e9ee5484ba5cda Mon Sep 17 00:00:00 2001
From: Alessio Quaglino <quaglino@google.com>
Date: Mon, 28 Apr 2025 16:22:55 -0700
Subject: [PATCH] Add missing PointToLocal call in mjCPlugin copy constructor.

PiperOrigin-RevId: 752486555
Change-Id: I08b14476b9098e6473a4c00918ef3f9a287f35f6
---
 python/mujoco/specs_test.py | 11 +++++++++++
 src/user/user_objects.cc    | 11 +++++++++++
 src/user/user_objects.h     |  3 +++
 3 files changed, 25 insertions(+)

diff --git a/python/mujoco/specs_test.py b/python/mujoco/specs_test.py
index 210d833f..e8aafa23 100644
--- a/python/mujoco/specs_test.py
+++ b/python/mujoco/specs_test.py
@@ -861,6 +861,17 @@ class SpecsTest(absltest.TestCase):
     self.assertEqual(model.nplugin, 1)
     self.assertEqual(model.npluginattr, 7)
     self.assertEqual(model.body_plugin[1], 0)
+    attributes = (''.join([chr(i) for i in model.plugin_attr]).split(chr(0)))
+    self.assertEqual(attributes[:2], ['10', '1'])
+
+    copy = spec.copy()  # before assigning the new config
+    wrong_config = {'wrong': '10', 'bend': '1'}
+    for s in [spec, copy]:
+      s.plugins[0].config = wrong_config
+      with self.assertRaisesRegex(
+          ValueError, "Error: unrecognized attribute 'plugin:wrong'"
+      ):
+        s.compile()
 
   def test_recompile_error(self):
     main_xml = """
diff --git a/src/user/user_objects.cc b/src/user/user_objects.cc
index d609621c..cff97b72 100644
--- a/src/user/user_objects.cc
+++ b/src/user/user_objects.cc
@@ -7271,6 +7271,8 @@ mjCPlugin::mjCPlugin(mjCModel* _model) {
   spec.plugin_name = &plugin_name;
   spec.name = &name;
   spec.info = &info;
+
+  PointToLocal();
 }
 
 
@@ -7289,11 +7291,20 @@ mjCPlugin& mjCPlugin::operator=(const mjCPlugin& other) {
     parent = this;
     plugin_slot = other.plugin_slot;
   }
+  PointToLocal();
   return *this;
 }
 
 
 
+void mjCPlugin::PointToLocal() {
+  spec.element = static_cast<mjsElement*>(this);
+  spec.name = &name;
+  spec.info = &info;
+}
+
+
+
 // compiler
 void mjCPlugin::Compile(void) {
   mjCPlugin* plugin_instance = this;
diff --git a/src/user/user_objects.h b/src/user/user_objects.h
index 16aa57af..bfec0797 100644
--- a/src/user/user_objects.h
+++ b/src/user/user_objects.h
@@ -1587,6 +1587,9 @@ class mjCPlugin : public mjCPlugin_ {
   mjCPlugin(mjCModel*);
   mjCPlugin(const mjCPlugin& other);
   mjCPlugin& operator=(const mjCPlugin& other);
+
+  void PointToLocal();
+
   mjsPlugin spec;
   mjCBase* parent;  // parent object (only used when generating error message)
   int plugin_slot;  // global registered slot number of the plugin