Midway through function `org-agenda-align-tags', there's a call to
`add-text-properties' that attempts to take an existing text property
and add symbols `org-tag' and `face' to it. Since around org-mode
version 5.17 or so, I've noticed problems with the lists formed there --
particularly on XEmacs 21.4.21 (Cygwin build).

Sometimes the existing text property already contains the symbol
`org-tag'. Sometimes the existing text property is already a list;
sometimes it's just an atom. I'm guessing the intent of the forms in
`org-agenda-align-tags' is ensure that `org-tag' is part of the text
properties; if it's already there, we should leave it there.

Toward that end, I've found the following change makes things work as
expected.

>From 80515d825ed6b619008df9afaffc4cc0f925f754 Mon Sep 17 00:00:00 2001
From: Steven E. Harris <[EMAIL PROTECTED]>
Date: Fri, 25 Jul 2008 20:24:08 -0400
Subject: [PATCH] Conditionally add symbol `org-tag' only when it's not already part of
 the text properties.

---
 lisp/org-agenda.el |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/lisp/org-agenda.el b/lisp/org-agenda.el
index 9a7ed8b..33c2a39 100644
--- a/lisp/org-agenda.el
+++ b/lisp/org-agenda.el
@@ -4768,8 +4768,12 @@ the new TODO state."
 				(if line (point-at-eol) nil) t)
 	(add-text-properties
 	 (match-beginning 2) (match-end 2)
-	 (list 'face (delq nil (list 'org-tag (get-text-property
-					       (match-beginning 2) 'face)))))
+	 (list 'face (delq nil (adjoin 'org-tag
+                                       (let ((prop (get-text-property
+                                                    (match-beginning 2) 'face)))
+                                         (if (listp prop)
+                                             prop
+                                           (list prop)))))))
 	(setq l (- (match-end 2) (match-beginning 2))
 	      c (if (< org-agenda-tags-column 0)
 		    (- (abs org-agenda-tags-column) l)
-- 
1.5.6

Rather than unconditionally prepending `org-tag' to the existing text
property, I used `adjoin' here. Also, since the text property is
sometimes a list and sometimes just an atom, I make sure that we make an
atom into a list before feeding it to `adjoin'.

I've been applying this same change to the source every time I upgrade
org-mode. Since the last time, I can see that there was a change here to
strip nil property elements, but I'm guessing not too many others have
seen the same problem with malformed text property lists.

Please let me know if anyone would like more detail on the malformed
text property lists I've seen arise without this patch in place.

-- 
Steven E. Harris
_______________________________________________
Emacs-orgmode mailing list
Remember: use `Reply All' to send replies to the list.
Emacs-orgmode@gnu.org
http://lists.gnu.org/mailman/listinfo/emacs-orgmode

Reply via email to