Fixed bug 3950 - Don't always call dbus_shutdown in SDL_DBus

Alexander Larsson

dbus_shutdown() is a debug feature which closes all global resources in the dbus library. Calling this should be done by the app, not a library, because if there are multiple users of dbus in the process then SDL could shut it down even though another part is using it.

For example, i had an issue with this in mGBA, which uses both Qt and SDL, both using libdbus. I had a session bus, but no system bus (this was in a flatpak sandbox), and when SDL_DBus_Init() failed to init the system bus it called dbus_shudown() and continued on. This caused issues for Qt when running due to its session bus connections having disappeared beneath it.

src/core/linux/SDL_dbus.c

@@ -139,9 +139,14 @@ SDL_DBus_Quit(void)
         dbus.connection_close(dbus.session_conn);
         dbus.connection_unref(dbus.session_conn);
     }
+/* Don't do this - bug 3950
+   dbus_shutdown() is a debug feature which closes all global resources in the dbus library. Calling this should be done by the app, not a library, because if there are multiple users of dbus in the process then SDL could shut it down even though another part is using it.
+*/
+#if 0
     if (dbus.shutdown) {
         dbus.shutdown();
     }
+#endif
     SDL_zero(dbus);
     UnloadDBUSLibrary();
 }