With your patch, it is smoother now. I don’t known if there is a better way to do this(skipping redisplay for this event when there is an immediate following event).
在 2019年12月4日 +0800 PM11:37，tsuucat via Bug reports for GNU Emacs, the Swiss army knife of text editors <bug-gnu-emacs@gnu.org>，写道：
> Hello.
>
>
> As far as I tried, Emacs with macOS native input method still flicker.
> I use default Japanese input method of macOS. Flicker happens when I
> press RET to input selected candidates.
>
> This is because insertText: in nsterm.m is called and emits a special
> event '(ns-unput-working-text) and then normal input events.
> read_char() function which processes these events always call redisplay()
> just after processing '(ns-unput-working-text) event.
>
> We have to prevent redisplay after '(ns-unput-working-text) event
> emited by insertText:. To do it, I made a patch. I don’t know this
> is corrent way to prevent redisplaying.
>
> --
> tsuucat