Subject: Re: bug#39265: 26.3; format-mode-line with FACE argument

From: Eli Zaretskii <[email-masked]>
Date: Fri, 24 Jan 2020 17:36:15 +0200

tags 39265 notabug
thanks

> From: [email-masked]
> Date: Sat, 25 Jan 2020 00:05:25 +0900
> 
> 
> #'format-mode-line assumes all characters of a string have a same 'face
> property value and checks only the first character.

Yes.  The reason is performance: the mode line is redrawn very
frequently, basically, after every command.

This is not a bug, this is the intended behavior.