Fixed bug when using DRCP with a 23c Oracle Database.

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -25,6 +25,7 @@ Thin Mode Changes
 #)  Fixed bug which could cause a redirect loop with improperly configured
     listener redirects.
 #)  Fixed bug when executing PL/SQL with a large number of binds.
+#)  Fixed bug when using DRCP with a 23c Oracle Database.
 
 Thick Mode Changes
 ++++++++++++++++++

src/oracledb/impl/thin/messages.pyx

@@ -2238,3 +2238,26 @@ cdef class RollbackMessage(Message):
         Perform initialization.
         """
         self.function_code = TNS_FUNC_ROLLBACK
+
+
+@cython.final
+cdef class SessionReleaseMessage(Message):
+
+    cdef:
+        uint32_t release_mode
+
+    cdef int _initialize_hook(self) except -1:
+        """
+        Perform initialization.
+        """
+        self.message_type = TNS_MSG_TYPE_ONEWAY_FN
+        self.function_code = TNS_FUNC_SESSION_RELEASE
+
+    cdef int _write_message(self, WriteBuffer buf) except -1:
+        """
+        Write the message for a DRCP session release.
+        """
+        self._write_function_code(buf)
+        buf.write_uint8(0)                  # pointer (tag name)
+        buf.write_uint8(0)                  # tag name length
+        buf.write_ub4(self.release_mode)    # mode

src/oracledb/impl/thin/protocol.pyx

@@ -102,7 +102,7 @@ cdef class Protocol:
                     message = conn_impl._create_message(RollbackMessage)
                     self._process_message(message)
                 if conn_impl._drcp_enabled:
-                    self._release_drcp_session(self._write_buf, release_mode)
+                    self._release_drcp_session(conn_impl, release_mode)
                     conn_impl._drcp_establish_session = True
 
             # if the connection is part of a pool, return it to the pool
@@ -397,20 +397,16 @@ cdef class Protocol:
             buf.skip_raw_bytes(3)
             message.error_info.message = buf.read_str(TNS_CS_IMPLICIT)
 
-    cdef int _release_drcp_session(self, WriteBuffer buf,
+    cdef int _release_drcp_session(self, ThinConnImpl conn_impl,
                                    uint32_t release_mode) except -1:
         """
         Release the session back to DRCP. Standalone sessions are marked for
         deauthentication.
         """
-        buf.start_request(TNS_PACKET_TYPE_DATA)
-        buf.write_uint8(TNS_MSG_TYPE_ONEWAY_FN)
-        buf.write_uint8(TNS_FUNC_SESSION_RELEASE)
-        buf.write_uint8(0)                  # seq number
-        buf.write_uint8(0)                  # pointer (tag name)
-        buf.write_uint8(0)                  # tag name length
-        buf.write_ub4(release_mode)         # mode
-        buf.end_request()
+        cdef SessionReleaseMessage message
+        message = conn_impl._create_message(SessionReleaseMessage)
+        message.release_mode = release_mode
+        message.send(self._write_buf)
 
     cdef int _reset(self, Message message) except -1:
         cdef uint8_t marker_type