Improve comment
diff --git a/Source/Modules/php.cxx b/Source/Modules/php.cxx
index e85dd69..d5f7a5b 100644
--- a/Source/Modules/php.cxx
+++ b/Source/Modules/php.cxx
@@ -1671,7 +1671,9 @@
Printf(s_oinit, " SWIGTYPE_%s_ce->create_object = %s_object_new;\n", class_name, class_name);
Printf(s_oinit, " memcpy(&%s_object_handlers,zend_get_std_object_handlers(), sizeof(zend_object_handlers));\n", class_name);
Printf(s_oinit, " %s_object_handlers.clone_obj = NULL;\n", class_name);
- // If not defined we aren't wrapping this type being passed or returned.
+ // If not defined we aren't wrapping any functions which use this type as a
+ // parameter or return value, in which case we don't need the clientdata
+ // set.
Printf(s_oinit, "#ifdef SWIGTYPE_p%s\n", SwigType_manglestr(Getattr(n, "classtypeobj")));
Printf(s_oinit, " SWIG_TypeClientData(SWIGTYPE_p%s,SWIGTYPE_%s_ce);\n", SwigType_manglestr(Getattr(n, "classtypeobj")), class_name);
Printf(s_oinit, "#endif\n");
