SDL_TEXTINPUT when holding Control, only on Firefox

[TrevorSundberg]

I made a simple SDL application to test this behavior. This is basically first hitting LCtrl, then V (hence two keydowns) and then letting go of V and then LCtrl (two keyups), effectively pressing Ctrl+V:

Chrome 67.0.3396.99 (64-bit):

SDL_KEYDOWN state: 1, scan: 224, sym: 1073742048
Ctrl 1
SDL_KEYDOWN state: 1, scan: 25, sym: 118
Ctrl 1
SDL_KEYUP   state: 0, scan: 25, sym: 118
Ctrl 1
SDL_KEYUP   state: 0, scan: 224, sym: 1073742048
Ctrl 0

Edge 42.17134.1.0 (64-bit):

SDL_KEYDOWN state: 1, scan: 224, sym: 1073742048
Ctrl 1
SDL_KEYDOWN state: 1, scan: 25, sym: 118
Ctrl 1
SDL_KEYUP   state: 0, scan: 25, sym: 118
Ctrl 1
SDL_KEYUP   state: 0, scan: 224, sym: 1073742048
Ctrl 0

Opera 54.0.2952.60 (64-bit):

SDL_KEYDOWN state: 1, scan: 224, sym: 1073742048
Ctrl 1
SDL_KEYDOWN state: 1, scan: 25, sym: 118
Ctrl 1
SDL_KEYUP   state: 0, scan: 25, sym: 118
Ctrl 1
SDL_KEYUP   state: 0, scan: 224, sym: 1073742048
Ctrl 0

Firefox 61.0.1 (64-bit):

SDL_KEYDOWN state: 1, scan: 224, sym: 1073742048
Ctrl 1
SDL_KEYDOWN state: 1, scan: 25, sym: 118
Ctrl 1
SDL_TEXTINPUT v
Ctrl 1
SDL_KEYUP   state: 0, scan: 25, sym: 118
Ctrl 1
SDL_KEYUP   state: 0, scan: 224, sym: 1073742048
Ctrl 0

There is basically a SDL_TEXTINPUT in the middle only on Firefox. Obviously in our own code we can just ignore it when Ctrl is pressed, however I thought you might like to know the difference exists.

Just for testing... really rough program, don't judge me :P

  SDL_Event event;
  while (SDL_PollEvent(&event))
  {
    if (event.type == SDL_KEYDOWN)
      printf("SDL_KEYDOWN state: %d, scan: %d, sym: %d\n", event.key.state, event.key.keysym.scancode, event.key.keysym.sym);
    if (event.type == SDL_KEYUP)
      printf("SDL_KEYUP   state: %d, scan: %d, sym: %d\n", event.key.state, event.key.keysym.scancode, event.key.keysym.sym);
    if (event.type == SDL_TEXTINPUT)
      printf("SDL_TEXTINPUT %s\n", event.text.text);
    
    if (event.type == SDL_KEYDOWN || event.type == SDL_KEYUP || event.type == SDL_TEXTINPUT)
      printf("Ctrl %d\n", (int)(SDL_GetKeyboardState(NULL)[SDL_SCANCODE_LCTRL] || SDL_GetKeyboardState(NULL)[SDL_SCANCODE_RCTRL]));
    
    fflush(stdout);
  }

[TrevorSundberg]

Also I just tested that other browsers do not give SDL_TEXTINPUT when Alt is held, but Firefox does.