Samuel Hopkins
Just confirming that the patch from Andreas (attachment 1715 [details]) works for me under SDL 2.0.3 with xmonad.
Stas Sergeev
Confirming that the patch in this ticket fixes the full-screen switching for dosemu2 on ubuntu-16.04. Note that I am not using xmonad, so this bug appears to be generic.
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().