Re: Question about display engine

[martin rudalics]

> Any way my question comes from 2 frequent use cases I don't know what's
> the expected behavior:
>
> 1) Base face sets background and extend; and face sets only background.
>
> 2) Base face sets extend but not background; and face sets both.
>
> in what condition the :extend attribute goes to the merged face? Always?
> when in base_face? When in face?

Assuming that "base face" is merged in before "face", both should
conceptually expand face.  The problematic case is

Base face sets background and extend to t; and face sets background to
t and extend to nil.

In this case merge should provide to show normal text with face but
extend the background of the basic face.

martin