the move to SDL2 seemingly caused certain button hotkeys (e.g. "pagedown") to be broken

[ipochto]

https://discord.com/channels/780082494447288340/780082494447288344/905536724980072458

Andrettin:

the problem are these lines in video/sdl.cpp:

    for (i = SDLK_F1; i <= SDLK_F15; ++i) {
        snprintf(str, sizeof(str), "f%d", i - SDLK_F1 + 1);
        Key2Str[i] = str;
        snprintf(str, sizeof(str), "F%d", i - SDLK_F1 + 1);
        Str2Key[str] = i;
    }

SDLK_F13 to SDLK_F15 no longer have values adjacent to SDLK_F12
so we need two loops instead:

    for (i = SDLK_F1; i <= SDLK_F12; ++i) {
        snprintf(str.data(), sizeof(str), "f%d", i - SDLK_F1 + 1);
        Key2Str[i] = str.data();
        snprintf(str.data(), sizeof(str), "F%d", i - SDLK_F1 + 1);
        Str2Key[str.data()] = i;
    }

    for (i = SDLK_F13; i <= SDLK_F24; ++i) {
        snprintf(str.data(), sizeof(str), "f%d", i - SDLK_F13 + 13);
        Key2Str[i] = str.data();
        snprintf(str.data(), sizeof(str), "F%d", i - SDLK_F13 + 13);
        Str2Key[str.data()] = i;
    }

relevant wyrmgus commit:
Andrettin/Wyrmgus@de74fe7