Simon Hug
There are currently three entry points in the SDL2_main code for windows: main, wmain and WinMain. Only the latter two properly convert the arguments to UTF-8.
Console applications linked with MSVC will always link with the main entry point (wmain has to be selected by manually setting the entry point). This makes it likely that such programs will not have proper unicode arguments.
Simon Hug
The SDLmain file src/main/windows/SDL_windows_main.c defines both entry points for console applications, main and wmain. This seems to confuse MSVC. It outputs a LNK4067 warning and then chooses main, which is a shame because only wmain has the unicode handling. Using SDLmain.lib provided on libsdl.org, the linker also goes for main.
I'm proposing to not define the main entry point at all. wmain should be supported well enough with MSVC.
Simon Hug
The function console_wmain in src/main/windows/SDL_windows_main.c does not null terminate the argument list it is creating. As specified by the C standard, "argv[argc] shall be a null pointer."
The SDLTest framework makes use of that null pointer and some test programs can cause an access violation because it's missing.
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().