Regression: "Window framebuffer support not available" error if software renderer is explicitly enforced in the SDL_HINT_RENDER_DRIVER

[olekolek1000]

How to reproduce:

Method 1:
testdrawchessboard.c:

int main() {
   SDL_SetHint(SDL_HINT_RENDER_DRIVER, "software");
   (...)

or just running via

SDL_RENDER_DRIVER=software ./test/testdrawchessboard

(Parameter 'window' is invalid)

[slouken]

What platform are you seeing this on? Are you testing with the latest code?
I tested on Windows both with and without forcing the rendering path, and in each case the software renderer wasn't used and the window surface was successfully created.

[olekolek1000]

It's Linux, tested again with the latest commit (9d47dae):

SDL_RENDER_DRIVER=software ./test/testdrawchessboard
ERROR: Render creation for surface fail : Parameter 'window' is invalid

SDL_RENDER_DRIVER=opengl and others work just fine.

[slouken]

I just tested and that same setup works fine here.

That error message means that SDL_CreateSoftwareRenderer() failed, which doesn't make any sense because the hint shouldn't affect that, and there is never any window in that code path. Can you debug that function to see what's happening?

[olekolek1000]

Differences between the environment flag and without it:
In testdrawchessboard.c:133, SDL_GetWindowSurface(window) returns null instead of SDL_Surface
In SDL_video.c:3371, SDL_CreateWindowFramebuffer returns null instead of SDL_Surface
In SDL_video.c:3311, ShouldAttemptTextureFramebuffer is false, thus created_framebuffer is never set, returning null

Removing this piece of code (which was introduced in 5c8d92e ) mitigates this issue.

[olekolek1000]

SDL_CreateSoftwareRenderer fails here:

SDL_render.c, SDL_CreateRendererWithProperties:

    if ((!window && !surface) || (window && surface)) {
        SDL_InvalidParamError("window");
        goto error;
    }

Parameter window is null here, because SDL_GetProperty(props, SDL_PROP_RENDERER_CREATE_WINDOW_POINTER, NULL) returns a null pointer here.

surface is null here because SDL_GetWindowSurface() returns null before calling this function, and SDL_SetProperty is set with a null surface.

[slouken]

Okay, I'm able to reproduce this on Wayland, thanks!

[slouken]

Fixed, thanks!