From: Leo Liu <sdl.web@gmail.com>
Cc: 31772@debbugs.gnu.org, tino.calancha@gmail.com
Date: Tue, 11 Sep 2018 18:26:36 +0800
The difference is on what to return when (up-list -1) fails. They both
try to return the sexp at point but the patched behaviour try returning
the whole sexp while the one in <= 25.1 cut off the sexp from point.
Looking at the code in 25.1 it looks to me the original author had a
thinko i.e. he/she meant to write:
(if (>= opoint (point))
(cons (point) end))
but instead write
(if (>= opoint (point))
(cons opoint end))
which resulted in some weird cases that you mentioned in previous email.
Right.
Would it be possible to modify list-at-point so that it keeps the
current behavior, perhaps as an option? I'd like to find a solution
that doesn't just revert to the old behavior, but allows those who
need the new behavior to have it in some reasonable way.
Yes, this can be done. For example:
optional ignore-comment-or-string)
"Return the Lisp list at
(defun list-at-point (& point, or nil if none is found.
If IGNORE-COMMENT-OR-STRING is non-nil comments and strings are
treated as white space."
(let ((ppss (and ignore-comment-or-string (syntax-ppss))))
(save-excursion
(goto-char (or (nth 8 ppss) (point)))
(form-at-point 'list 'listp))))
Would you mind submitting a patch that includes the above, and also
fixes/augments the tests accordingly? I think these changes then
could go into the emacs-26 branch, unless someone raises objections.
Thanks.