No keydown/keyup events for one key on swiss german layout

I built b75e82af5ef1 (current head of default) on Windows and used the checkkeys
test to see how all the keys get reported. The key with $/?/} doesn’t produce
SDL keydown and keyup events. It’s the key right beside the return key.

http://www.forlanglab.lsu.edu/exams/KeyboardLayout/images/Keyboards/Swiss.png

WIN_WindowProc receives WM_KEYDOWN with the Windows virtual code 223 (0xdf)
and the Windows scan code 43 (0x2b). The virtual code then gets mapped to
SDL_SCANCODE_UNKNOWN through windows_scancode_table. SDL_SendKeyboardKey
discards SDL_SCANCODE_UNKNOWN immediately and doesn’t add any events.

I guess this may be also the case with other layouts.
Is this expected behaviour?

I’m new to mailing lists. Please correct me if I did something wrong.
Thanks.