bug#37774: 27.0.50; new :extend attribute broke visuals of all themes and other packages

[Ergus]

Hi:

I just saw this message and I was going to look into it but I see that
there is a today's commit related with the extend feature.

Eli did you already fixed this? Or is it still pending?



On Thu, Dec 05, 2019 at 05:48:22PM +0100, K??vin Le Gouguec wrote:
> martin rudalics <rudalics@gmx.at> writes:
>
> > > Please push it for me.
> >
> > Pushed now.  Please have a look.
>
> (For context: this was commit 8232325337 "Handle case where a face's
> :extend attribute is unspecified (Bug#37774)".)
>
> I think there might have been a regression since this commit: in-between
> 1c29ba0340 (2019-11-17) and 21790e5473 (2019-12-05), something caused
> the backgrounds to no longer extend for faces with unspecified :extend
> inheriting faces with :extend t.
>
> The attached theme sets :extend t for diff-{added,removed}, and sets
> :inherit (diff-???) for ediff-fine-diff-{A,B}.


> From emacs -Q, running the following code:
>
>    (add-to-list 'custom-theme-load-path default-directory)
>    (load-theme 'extend-inherit t)
>    (ediff-files "/usr/share/common-licenses/LGPL-2" 
> "/usr/share/common-licenses/LGPL-2.1")
>
> ??? gives the following results with commit 1c29ba0340:


> ??? and the following results with commit 21790e5473:


> Is this deliberate?  I don't think I read anything in this thread
> suggesting it; apologies if I missed something.
>
> If it's a bug, maybe this is due to recent changes in xfaces.c?
>
>    git log --oneline 1c29ba0340..21790e5473 -- src/xfaces.c
>    d4515f3cab Support ':extend' in faces defined by list of key/value pairs
>    19aecd340b Fix face merging when some have :extend non-nil and some are 
> inherited