Re: :extend t inheritance

[Ergus <spacibba@aol.com>]

Hi:

I just added a branch `fix/inherit_extend_face` that fixes the issue
with inheritance of the extend attribute with filter condition.

There are two commits because I also detected another issue in gui I
didn't see before because I don't use gui normally.

Please give it a look and if everything is fine I'll move it to master
ASAP.

On Thu, Oct 24, 2019 at 04:46:08PM +0300, Eli Zaretskii wrote:
>> From: Ingo Lohmar <ingo.lohmar@posteo.net>
>> Date: Wed, 23 Oct 2019 22:34:05 +0200
>>
>> I am messing around with the face :extend attribute and I am wondering
>> about sth.  The elisp manual says
>>
>>      The value should be ???t??? to display the empty space between end of
>>      line and edge of the window using this face, or ???nil??? to not use
>>      this face for the space between the end of the line and the edge of
>>      the window.  When Emacs merges several faces for displaying the
>>      empty space beyond end of line, only those faces with ???:extend???
>>      non-???nil??? will be merged.
>>
>> I briefly read the original discussion of this feature, but did not find
>> a reason for this peculiar behavior when it comes to inheritance; if
>> there was a reason given, could someone point me to it?
>
>I don't think I understand what you are saying or asking.  The text
>that you cite doesn't mention inheritance at all.  Could you clarify
>the issue?
>
>> Background: I manage all faces without themes on my own, and I rely
>> heavily on inheritance.  As it stands now, IIUC (and according to some
>> tests), I have to specify :extend t on ~30 faces (mostly diff, ediff,
>> smerge, magit-ediff and -blame etc) that all derive from 3 or 4 base
>> faces.  It seems to me that this renders the whole point of inheritance
>> moot.
>>
>> My natural reaction would have been to specify :extend t on some base
>> faces, and for faces that inherit from them, explicitly say :extend nil
>> only for those faces for which I do not want that extension.  Isn't that
>> at least as flexible, and more in the spirit of inheriting attributes?
>
>Are you saying that the :extend attribute isn't inherited via
>:inherit?  Or are you saying something else?  In any case, could you
>please show a recipe or an example of what you tried and how the
>results didn't match your expectations?
>
>Thanks.
>