Bugfix: Make sure property time comparison works correctly.
Hsiu-Khuern Tang writes:
I find that doing a tags search for SCHEDULED or DEADLINE turns
up headings that do not have any schedule or deadlines.
Using the example from
http://article.gmane.org/gmane.emacs.orgmode/10274:
#+SEQ_TODO: NEXT WAITING | DONE
#+STARTUP: overview
* DONE Test1
CLOSED: [2009-01-07 Wed 12:26]
* NEXT Test2
DEADLINE: <2009-01-28 Wed>
* Test3
If I type
C-c \ +DEADLINE<="<2009-01-28>" <RET>
all three headlines are selected! I expected to match the second
headline only.
Indeed, this exposes an error in the time comparison functions
which would take a empty time stamp to mean 0. This commit does
fix the bug.