On Wayland -- or at least on some Wayland implementations -- windows
aren't shown until something has been rendered into them. For the
'checkkeys' test program, this means that keyboard input isn't
registered, making the program rather useless.
By creating a renderer and presenting once, the window is properly
displayed, and the test behaves as it does under X11 (including
XWayland).
The exact same thing was done with testmessge in 1cd97e2695 (PR #4252)
Eric Wasylishen
Small change to checkkeys so you can toggle text input mode with a mouse click.
This is needed for testing how dead keys react to toggling mouse input, i.e. these bugs:
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().
