Created attachment 376 [details]
Support for disabling stdio redirect with environment variables.

Many a programmer finds it annoying that the standard streams stdout and stderr
are by default redirected to the corresponding files, as printf is an important
means of debugging. Altering this behaviour requires basically recompiling the
SDLmain part of the library modifying the build environment to skip WinMain.
Both of these options are difficult for newbies to understand, and while the
second one can probably be done, it would cause the terminal window to become
always visible, which usually is not what the programmer wishes. The
documentation provides some more hacks, namely reopening the files again with
the file name "CON", but this is not a portable solution, as other systems will
take this as a literal file name and produce a file named CON instead of
printing to the console.

I see two possible resolutions.

The redirection could be set explicitly in one of these ways:
SDL_Init(SDL_INIT_STDIO_REDIRECT);
SDL_Init(SDL_INIT_NO_STDIO_REDIRECT);
SDL_EnableRedirect(SDL_REDIRECT_STDOUT | SDL_REDIRECT_STDERR);
SDL_DisableRedirect(SDL_REDIRECT_ALL);

The other option is to use an environment variable:
SDL_NO_STDIO_REDIRECT=1 program.exe
SDL_STDIO_REDIRECT=0 program.exe

I have implemented the latter ones in the attached patch.