Re: [PATCH] gitk: check main window visibility before waiting for it to show

> From: Tobias Pietzsch <pietzsch@mycroft.speedport.ip>
>
> If the main window is already visible when gitk waits for it to
> become visible, gitk hangs forever.
> This commit adds a check whether the window is already visible.
> See https://wiki.tcl-lang.org/page/tkwait+visibility
>
> Signed-off-by: Tobias Pietzsch <pietzsch@mycroft.speedport.ip>
> ---
>     gitk: check main window visibility before waiting for it to show
>
>     If the main window is already visible when gitk waits for it to become
>     visible, gitk hangs forever.
>
>     This commit adds a check whether the window is already visible. See
>     https://wiki.tcl-lang.org/page/tkwait+visibility
>
>     The symptom of the for-ever waiting is that gitk shows just an empty
>     window, like this: https://tinyurl.com/yxr5qlf6 It happens (to me) on
>     macOS 11.1 with git-gui installed via homebrew. It doesn't happen on
>     macOS 10.14.