Allow body attribute in actuator/plugin.

Author: frankpzh

doc/XMLreference.rst

@@ -5980,10 +5980,12 @@ Associate this actuator with an :ref:`engine plugin<exPlugin>`. Either :at:`plug
 
 .. _actuator-plugin-actearly:
 
+.. _actuator-plugin-body:
+
 .. |actuator/plugin attrib list| replace:: :at:`name`, :at:`class`, :at:`group`, :at:`actlimited`, :at:`ctrllimited`,
    :at:`forcelimited`, :at:`ctrlrange`, :at:`forcerange`, :at:`lengthrange`, :at:`gear`, :at:`cranklength`,
    :at:`joint`, :at:`jointinparent`, :at:`site`, :at:`tendon`, :at:`cranksite`, :at:`slidersite`, :at:`user`,
-   :at:`actdim`, :at:`dynprm`, :at:`actearly`
+   :at:`actdim`, :at:`dynprm`, :at:`actearly`, :at:`body`
 
 |actuator/plugin attrib list|
    Same as in actuator/ :ref:`general <actuator-general>`.

src/xml/xml_native_reader.cc

@@ -428,11 +428,11 @@ const char* MJCF[nMJCF][mjXATTRNUM] = {
             "lmin", "lmax", "vmax", "fpmax", "fvmax"},
         {"adhesion", "*", "9", "name", "class", "group",
             "forcelimited", "ctrlrange", "forcerange", "user", "body", "gain"},
-        {"plugin", "*", "25", "name", "class",  "plugin", "instance", "group",
+        {"plugin", "*", "26", "name", "class",  "plugin", "instance", "group",
             "ctrllimited", "forcelimited", "actlimited", "ctrlrange", "forcerange", "actrange",
             "lengthrange", "gear", "cranklength", "joint", "jointinparent",
             "site", "actdim", "dyntype", "dynprm", "tendon", "cranksite", "slidersite", "user",
-            "actearly"},
+            "actearly", "body"},
         {"<"},
           {"config", "*", "2", "key", "value"},
         {">"},