Hello all,

I am currently trying to setup clamping windows to the edges of the screen when they're being created. This is mostly used for popups/context-menus.

My calculations are all fine, however when I pass the variables to `SDL_CreateWindow` the created window sticks out to the right by 2 * the border of the window.
So I tried polling `SDL_GetWindowBordersSize`. This however always sets all variables to 0 (and returns 0 as well so it's successful) if polled immediately after the window creation. 
After some digging I figured out that this has to do with the fact that SDL doesn't post a `_NET_REQUEST_FRAME_EXTENTS` to the window manager during window creation.

I believe this to be a bug since it appears that SDL internally also takes this into account. If I just call `SDL_CreateWindow(args)` the window sticks out to the right. If I add a `std::this_thread::sleep_for(50ms)` after the window creation it is properly aligned at the right screen edge without any overhang. This seemingly indicates that SDL wants to take the border-size into account but can't because the values aren't there yet since they haven't been requested from the WM.

sincerely,
Folling