When using S-<up> to modify a date with an our range in Org 7.5, I get
"symbol function's definition is null : signum".
E.g. <2011-03-10 jeu. 10:30-11:30>
It appears that (org-modify-ts-extra) is using this function, but
unlike in CL isn't not an elisp built-in :)
As a work-around I added an internal defun:
(defun org-modify-ts-extra (s pos n dm)
"Change the different parts of the lead-time and repeat fields in timestamp."
(defun signum (x)
(cond
((> x 0) 1)
((< x 0) -1)
((= x 0) 0)))
[...]
--
Sylvain
