bug#11732: 24.1; Microsoft IME Japanese input problem

[Eli Zaretskii]

> Date: Tue, 17 Feb 2015 19:26:41 +0900
> From: Fujii Hironori <fujii.hironori@gmail.com>
> 
> WM_IME_STARTCOMPOSITION should be passed to DefWindowProc.

Thanks, but can you explain the details?

I can understand why we should defer to DefWindowProc if we refrain
from processing this message, for some reason.  But this last part of
your patch:

> @@ -3318,17 +3318,17 @@ w32_wnd_proc (HWND hwnd, UINT msg, WPARAM wParam, 
> LPARAM lParam)
>  
>         /* Punt if the window was deleted behind our back.  */
>         if (!BUFFERP (w->contents))
> -         break;
> +         goto dflt;
>  
>         context = get_ime_context_fn (hwnd);
>  
>         if (!context)
> -         break;
> +         goto dflt;
>  
>         set_ime_composition_window_fn (context, &form);
>         release_ime_context_fn (hwnd, context);
>       }
> -      break;
> +      goto dflt;
>  
>      case WM_IME_ENDCOMPOSITION:
>        ignore_ime_char = 0;

Passes the message to DefWindowProc even if we succeeded to handle
WM_IME_STARTCOMPOSITION by calling ImmSetCompositionWindow.  Why is
that needed?