Bug#49025: mysqld-debug: missing DBUG_RETURN or DBUG_VOID_RETURN macro in function "?func"

The problem was that the dbug facility was being used after the
per-thread dbug state had already been finalized. The was present
in a few functions which invoked decrement_handler_count, which
in turn invokes my_thread_end on Windows. In my_thread_end, the
per-thread dbug state is finalized. Any use after the state is
finalized ends up creating a new state.

The solution is to process the exit of a function before the
decrement_handler_count function is called.

sql/mysqld.cc

@@ -5213,9 +5213,9 @@ pthread_handler_t handle_connections_sockets(void *arg __attribute__((unused)))
 
     create_new_thread(thd);
   }
-
+  DBUG_LEAVE;
   decrement_handler_count();
-  DBUG_RETURN(0);
+  return 0;
 }
 
 
@@ -5311,8 +5311,9 @@ pthread_handler_t handle_connections_namedpipes(void *arg)
     create_new_thread(thd);
   }
   CloseHandle(connectOverlapped.hEvent);
+  DBUG_LEAVE;
   decrement_handler_count();
-  DBUG_RETURN(0);
+  return 0;
 }
 #endif /* __NT__ */
 
@@ -5548,9 +5549,9 @@ pthread_handler_t handle_connections_shared_memory(void *arg)
   if (handle_connect_file_map)	CloseHandle(handle_connect_file_map);
   if (event_connect_answer)	CloseHandle(event_connect_answer);
   if (smem_event_connect_request) CloseHandle(smem_event_connect_request);
-
+  DBUG_LEAVE;
   decrement_handler_count();
-  DBUG_RETURN(0);
+  return 0;
 }
 #endif /* HAVE_SMEM */
 #endif /* EMBEDDED_LIBRARY */