bug#1852: 23.0.60; describe-face: Wrong type argument: symbolp, (:slant oblique)

[Stephen Berman <stephen.berman@gmx.net>]

>> 1. emacs -q
>> 2. Put the cursor on any of the characters in the phrase "ABSOLUTELY NO
>> WARRANTY" in the splash screen.
>> 3. Type C-u C-x =
>> 4. In the resulting *Help* buffer click on the link labelled
>> "(variable-pitch (:slant oblique))"
>> => Emacs beeps and throws the error in the Subject line.
>
> Since anonymous faces can't be usefully customized, I've changed
> describe-face to ignore those.  Thanks for the bug report.

Your fix prevents the error from being raised at step 4 above; however,
the behavior is nevertheless still not what I would naively expect:
namely, now it switches to a *Help* buffer describing variable-pitch
face, containing the line
         Slant: unspecified
i.e., this is not the face that I clicked to get a description of (as
the tooltip also promises).  Wouldn't it be better (if readily
implementable) to exclude `(:slant oblique)' from the the describe-face
link?

Steve Berman