more verbose error messages when exception occurs during dc update

direct/src/distributed/cConnectionRepository.cxx

@@ -221,7 +221,8 @@ stop_delay() {
 #endif  // SIMULATE_NETWORK_DELAY
 
 ////////////////////////////////////////////////////////////////////
-//     Function: CConnectionRepository::check_datagram//       Access: Published
+//     Function: CConnectionRepository::check_datagram
+//       Access: Published
 //  Description: Returns true if a new datagram is available, false
 //               otherwise.  If the return value is true, the new
 //               datagram may be retrieved via get_datagram(), or
@@ -250,10 +251,9 @@ check_datagram() {
       unsigned char  wc_cnt;
       wc_cnt = _di.get_uint8();
       _msg_channels.clear();
-      for(unsigned char lp1 = 0; lp1 < wc_cnt; lp1++)
-      {
-            CHANNEL_TYPE  schan  = _di.get_uint64();
-            _msg_channels.push_back(schan);
+      for(unsigned char lp1 = 0; lp1 < wc_cnt; lp1++) {
+        CHANNEL_TYPE  schan  = _di.get_uint64();
+        _msg_channels.push_back(schan);
       }
       _msg_sender = _di.get_uint64();
       
@@ -576,6 +576,7 @@ handle_update_field() {
       Py_DECREF(distobj);
       
       if (PyErr_Occurred()) {
+        handle_python_exception();
         return false;
       }
     }
@@ -650,6 +651,7 @@ handle_update_field_owner() {
         Py_DECREF(distobjOV);
       
         if (PyErr_Occurred()) {
+          handle_python_exception();
           return false;
         }
       }
@@ -686,6 +688,7 @@ handle_update_field_owner() {
         Py_DECREF(distobj);
       
         if (PyErr_Occurred()) {
+          handle_python_exception();
           return false;
         }
       }
@@ -697,6 +700,53 @@ handle_update_field_owner() {
   return true;
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: CConnectionRepository::handle_python_exception
+//       Access: Private
+//  Description: Called when a Python exception is raised during
+//               processing of an update or whatever.  Gets the error
+//               string and passes it back to the calling Python
+//               process in a sensible way.
+////////////////////////////////////////////////////////////////////
+void CConnectionRepository::
+handle_python_exception() {
+  PyObject *exc, *val, *tb;
+  PyErr_Fetch(&exc, &val, &tb);
+
+  ostringstream strm;
+  strm << "\n";
+
+  PyObject *exc_name = PyObject_GetAttrString(exc, "__name__");
+  if (exc_name == (PyObject *)NULL) {
+    PyObject *exc_str = PyObject_Str(exc);
+    strm << PyString_AsString(exc_str);
+    Py_DECREF(exc_str);
+  } else {
+    PyObject *exc_str = PyObject_Str(exc_name);
+    strm << PyString_AsString(exc_str);
+    Py_DECREF(exc_str);
+    Py_DECREF(exc_name);
+  }
+  Py_DECREF(exc);
+
+  if (val != (PyObject *)NULL) {
+    PyObject *val_str = PyObject_Str(val);
+    strm << ": " << PyString_AsString(val_str);
+    Py_DECREF(val_str);
+    Py_DECREF(val);
+  }
+  if (tb != (PyObject *)NULL) {
+    Py_DECREF(tb);
+  }
+
+  strm << "\nException occurred while processing ";
+  describe_message(strm, "", _dg);
+  string message = strm.str();
+  nout << message << "\n";
+
+  nassert_raise(message);
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: CConnectionRepository::describe_message
 //       Access: Private
@@ -713,7 +763,10 @@ describe_message(ostream &out, const string &prefix,
   CHANNEL_TYPE do_id;
   int msg_type;
   bool is_update = false;
-  string full_prefix = "CR::" + prefix;
+  string full_prefix;
+  if (!prefix.empty()) {
+    full_prefix = "CR::" + prefix + ":";
+  }
 
   if (!_client_datagram) 
   {
@@ -756,9 +809,8 @@ describe_message(ostream &out, const string &prefix,
     if (msgName.length() == 0) {
       msgName += "unknown message ";
       msgName += msg_type;
-      msgName += "\n";
     }
-    out << full_prefix << ":" << msgName << "\n";
+    out << full_prefix << msgName << "\n";
     dg.dump_hex(out, 2);
 
   } else {
@@ -799,15 +851,14 @@ describe_message(ostream &out, const string &prefix,
     int field_id = packer.raw_unpack_uint16();
 
     if (dclass == (DCClass *)NULL) {
-      out << full_prefix << "update for unknown object " << do_id 
-          << ", field " << field_id << "\n";
+      out << full_prefix << "unknown_object(" << do_id 
+          << ").unknown_field(" << field_id << ")\n";
 
     } else {
-      out << full_prefix <<
-        ":" << dclass->get_name() << "(" << do_id << ").";
+      out << full_prefix << dclass->get_name() << "(" << do_id << ").";
       DCField *field = dclass->get_field_by_index(field_id);
       if (field == (DCField *)NULL) {
-        out << "unknown field " << field_id << "\n";
+        out << "unknown_field(" << field_id << ")\n";
         
       } else {
         out << field->get_name();

direct/src/distributed/cConnectionRepository.h

@@ -128,6 +128,7 @@ private:
   bool do_check_datagram();
   bool handle_update_field();
   bool handle_update_field_owner();
+  void handle_python_exception();
 
   void describe_message(ostream &out, const string &prefix, 
                         const Datagram &dg) const;