bug#51577: [External] : Re: bug#51577: 27.2; Regression: reproducible hang with face functions

[Eli Zaretskii]

> From: Drew Adams <drew.adams@oracle.com>
> CC: "51577@debbugs.gnu.org" <51577@debbugs.gnu.org>
> Date: Fri, 5 Nov 2021 02:41:09 +0000
> Accept-Language: en-US
> 
> > evalling a circular face definition should signal an error.
> 
> No.  The inheritance that causes the infloop
> should just not be done (ignored.)

I disagree.  Inheritance loop is an error in defining a face, and
should be flagged as such when detected.

> That sane behavior is exactly what was broken, in the case cited.

That "sane" behavior was actually a subtle bug.  I invite you to file
a bug against Emacs 26 that it didn't detect that.

> Inheritance of a face by itself should be
> ignored, silently.

DISAGREE!!