Make constraint island discovery on by default.

Also fix latent bug in mjData serialization.

PiperOrigin-RevId: 799505349
Change-Id: I299e7cc8133fa2ec0b339a7ff3d02543e06778b1

python/mujoco/bindings_test.py

@@ -946,7 +946,7 @@ Euler integrator, semi-implicit in velocity.
     self.assertEqual(mujoco.mjtEnableBit.mjENBL_OVERRIDE, 1 << 0)
     self.assertEqual(mujoco.mjtEnableBit.mjENBL_ENERGY, 1 << 1)
     self.assertEqual(mujoco.mjtEnableBit.mjENBL_FWDINV, 1 << 2)
-    self.assertEqual(mujoco.mjtEnableBit.mjNENABLE, 6)
+    self.assertEqual(mujoco.mjtEnableBit.mjNENABLE, 5)
     self.assertEqual(mujoco.mjtGeom.mjGEOM_PLANE, 0)
     self.assertEqual(mujoco.mjtGeom.mjGEOM_HFIELD, 1)
     self.assertEqual(mujoco.mjtGeom.mjGEOM_SPHERE, 2)

python/mujoco/introspect/enums.py

@@ -44,7 +44,8 @@ ENUMS: Mapping[str, EnumDecl] = dict([
              ('mjDSBL_EULERDAMP', 16384),
              ('mjDSBL_AUTORESET', 32768),
              ('mjDSBL_NATIVECCD', 65536),
-             ('mjNDISABLE', 17),
+             ('mjDSBL_ISLAND', 131072),
+             ('mjNDISABLE', 18),
          ]),
      )),
     ('mjtEnableBit',
@@ -57,8 +58,7 @@ ENUMS: Mapping[str, EnumDecl] = dict([
              ('mjENBL_FWDINV', 4),
              ('mjENBL_INVDISCRETE', 8),
              ('mjENBL_MULTICCD', 16),
-             ('mjENBL_ISLAND', 32),
-             ('mjNENABLE', 6),
+             ('mjNENABLE', 5),
          ]),
      )),
     ('mjtJoint',

python/mujoco/introspect/enums_test.py

@@ -43,8 +43,7 @@ class EnumsTest(absltest.TestCase):
                                           ('mjENBL_FWDINV', 1<<2),
                                           ('mjENBL_INVDISCRETE', 1<<3),
                                           ('mjENBL_MULTICCD', 1<<4),
-                                          ('mjENBL_ISLAND', 1<<5),
-                                          ('mjNENABLE', 6)))
+                                          ('mjNENABLE', 5)))
 
   # values mostly increment by one with occasional overrides
   def test_mjtGeom(self):  # pylint: disable=invalid-name

python/mujoco/structs_wrappers.cc

@@ -736,6 +736,7 @@ void MjDataWrapper::Serialize(std::ostream& output) const {
   X(nA);
   X(nefc);
   X(nisland);
+  X(nidof);
   X(time);
   X(energy);
 #undef X
@@ -815,6 +816,7 @@ MjDataWrapper MjDataWrapper::Deserialize(std::istream& input) {
   X(nA);
   X(nefc);
   X(nisland);
+  X(nidof);
   X(time);
   X(energy);
 #undef X