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

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

[Stephen Berman]

The bug described below still exists in GNU Emacs 23.0.60.28
(i686-pc-linux-gnu, GTK+ Version 2.14.4) of 2009-01-09 on escher, so I'm
submitting it to the bug tracker.  Note that the cited sexp from
faces.el is now at line 1360, not 1307.


From: Stephen Berman <Stephen.Berman@gmx.net>
Subject: describe-face: Wrong type argument: symbolp, (:slant oblique)
Newsgroups: gmane.emacs.devel
To: emacs-devel@gnu.org
Date: Mon, 26 May 2008 00:59:57 +0200

In GNU Emacs 23.0.60.4 (i686-pc-linux-gnu, GTK+ Version 2.12.0) of
2008-05-25 on escher

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.

This happens at line 1307 in faces.el, which is this sexp:

(insert "Face: " (symbol-name f))

when `f' gets the value `(:slant oblique)', which it does because the
list '(variable-pitch (:slant oblique)) is the value of 'face in the
plist of the character at point (as shown by text-properties-at).  I
don't know what the best fix is.

(In earlier versions of Emacs, including CVS trunk of 2007-08-24, this
value was '(variable-pitch :slant oblique), and doing the above steps
does not raise an error, but the resulting *Help* buffer contains these
dubious lines:

Face: :slant   undefined face.
Face: oblique   undefined face.

But in this version a wrong type argument error is also raised by the
above recipe for plist 'face values such as '(variable-pitch :foreground
"red"), on the string.  I could not determine when the change in the
representation of the plist value of 'face occurred, because I couldn't
figure out which part of the code constructs this plist.)

Steve Berman

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

[Emacs bug Tracking System]

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Your message dated Sun, 11 Jan 2009 12:29:10 -0500
with message-id <87tz8569ax.fsf@cyd.mit.edu>
and subject line Re: 23.0.60;  describe-face: Wrong type argument: symbolp, (:slant oblique)
has caused the Emacs bug report #1852,
regarding 23.0.60;  describe-face: Wrong type argument: symbolp, (:slant oblique)
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
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immediately.)


-- 
1852: http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=1852
Emacs Bug Tracking System
Contact owner@emacsbugs.donarmstrong.com with problems

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From: Stephen Berman <stephen.berman@gmx.net>
To: emacs-pretest-bug@gnu.org
Subject: 23.0.60;  describe-face: Wrong type argument: symbolp, (:slant oblique)
Date: Sat, 10 Jan 2009 22:20:13 +0100
Message-ID: <87y6xieu42.fsf@escher.local.home>

The bug described below still exists in GNU Emacs 23.0.60.28
(i686-pc-linux-gnu, GTK+ Version 2.14.4) of 2009-01-09 on escher, so I'm
submitting it to the bug tracker.  Note that the cited sexp from
faces.el is now at line 1360, not 1307.


From: Stephen Berman <Stephen.Berman@gmx.net>
Subject: describe-face: Wrong type argument: symbolp, (:slant oblique)
Newsgroups: gmane.emacs.devel
To: emacs-devel@gnu.org
Date: Mon, 26 May 2008 00:59:57 +0200

In GNU Emacs 23.0.60.4 (i686-pc-linux-gnu, GTK+ Version 2.12.0) of
2008-05-25 on escher

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.

This happens at line 1307 in faces.el, which is this sexp:

(insert "Face: " (symbol-name f))

when `f' gets the value `(:slant oblique)', which it does because the
list '(variable-pitch (:slant oblique)) is the value of 'face in the
plist of the character at point (as shown by text-properties-at).  I
don't know what the best fix is.

(In earlier versions of Emacs, including CVS trunk of 2007-08-24, this
value was '(variable-pitch :slant oblique), and doing the above steps
does not raise an error, but the resulting *Help* buffer contains these
dubious lines:

Face: :slant   undefined face.
Face: oblique   undefined face.

But in this version a wrong type argument error is also raised by the
above recipe for plist 'face values such as '(variable-pitch :foreground
"red"), on the string.  I could not determine when the change in the
representation of the plist value of 'face occurred, because I couldn't
figure out which part of the code constructs this plist.)

Steve Berman







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From: Chong Yidong <cyd@stupidchicken.com>
To: Stephen Berman <stephen.berman@gmx.net>
Cc: 1852-done@emacsbugs.donarmstrong.com
Subject: Re: 23.0.60;  describe-face: Wrong type argument: symbolp, (:slant oblique)
Date: Sun, 11 Jan 2009 12:29:10 -0500
Message-ID: <87tz8569ax.fsf@cyd.mit.edu>

> 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.