SDL Bug wrt. mouse focus?

We have basically finished the GUI subsystem of the game. However, when writing the Code to handle the mouse pointer leaving the application window (for example, to remove the hovering state of a widget near the window border) I investigated a problem which I think is a bug in SDL.

When clicking into a different window, holding the mouse button pressed, moving the cursor into our SDL window and release the mouse button there, then we don't get an SDL_ACTIVEEVENT which reports gained mouse focus for the window. This is OK as long as the mouse button is pressed, since all mouse events are still delivered to the originating window then.

The problem with this is that when querying the application state via SDL_GetAppState, SDL still reports the window not having mouse focus until the mouse leaves and enters the window again. This confuses our code since there are some checks for the application having mouse focus before e.g. setting a button's state to be hovered by the mouse.

There is a quite easy workaround for the problem:

SDL_WM_GrabInput(SDL_GRAB_ON);
SDL_WM_GrabInput(SDL_GRAB_OFF);

This is executed whenever the mouse moves over our window or it is clicked and SDL reports that we don't have mouse focus. In this case we can be quite sure that the mouse actually is over our window, so the mouse grab does not warp the mouse cursor. However, this causes SDL to update the application's mouse focus state.

There is still a little issue with this: When the mouse button is released over a button, the the button is not shown hovered until the next mouse click or movement, since the application state is only rechecked on these two events. However, that's not a major problem, and we can live with it.

I am not yet sure whether there is the same problem on Windows, but I have tested it using GNOME with the Metacity window manager. Anyway, as a good net citizen I filed a proper bug report.