bug#8454: deftheme, :inherit & overriding existing values

[Christoph Scholtes <cschol2112@googlemail.com>]

On 5/8/2011 2:14 PM, Chong Yidong wrote:

> OK, I found a bug in the case where defface is called after loading a
> theme with settings for that face.  The defface settings were not being
> applied; I've checked a fix into the trunk.  However, I'm not sure this
> is the issue you are talking about, since this bug was not specific to
> the :inherit property.  Could you check if your problem is fixed?
>
> One possible source of confusion, which may apply to Dirk-Jan's report,
> is that :inherit only tells Emacs to consult the parent face if a face
> attribute is unspecified.  If the attribute is specified, it overrides
> the inheritance.  So if your Custom theme want to "cancel out", say, any
> existing foreground attribute setting, you need something like
>
>   '(froob ((t (:foreground unspecified :inherit parent-face))))

This did not fix it for me.

I think Dirk-Jan and I have the same issue, though, which is the 
behavior of :inherit.

One example from my custom theme:

  '(erc-default-face ((t (:inherit default))))

This is supposed to inherit from

  '(default ((t (:background "#3f3f3f" :foreground "#dcdccc"))))

but it does not work.

This is probably related to what you describe above, but I don't really 
understand it. foregound in erc-default-face is unspecified, right? 
Should the inherit get the attributes from default or not?

I figured out a way to make my custom theme work, though. Loading it 
through customize does not work, but if I open the theme file and eval 
the buffer, it works and erc shows the my custom faces. Maybe this helps 
to troubleshoot the problem?

Christoph