SDL_GetError() returns "Parameter 'src' is invalid" after call to initscr() for sdl2

[bjadamson]

In this code path, SDL_GetError returns "Parameter 'src' is invalid" after the call to initscr.

The error comes from this code:

PDCurses/sdl2/pdcscrn.c

Lines 233 to 237 in f2d31a2

	if (!SP->mono && !pdc_back)
	{
	const char *bname = getenv("PDC_BACKGROUND");
	pdc_back = SDL_LoadBMP(bname ? bname : "pdcback.bmp");
	}

I guess it's not valid to call SDL_LoadBMP with NULL. Obviously I can work-around this by calling SDL_ClearError immediately after the call to initscr() but I think it would be cleaner long-term if this call causing an invalid error could be avoided in the first place.

I found this out because I started annotating all of my calls to SDL with checks using SDL_GetError(), and this came up.

[wmcbrine]

Eh, the point of bname ? bname : "pdcback.bmp" is precisely to avoid passing a NULL to SDL_LoadBMP.

[bjadamson]

Your right, I misunderstood what was happening yesterday. It's falling back to "pdcback.bmp" but that file doesn't exist, so SDL calls SDL_SetError which lead to the issue.