"log -rdate:" and "log -cdate:"

[Eli Zaretskii]

The "date:" revisionspec seem not to be entirely user-friendly in
conjunction with "bzr log".  Or maybe I'm missing something.

The use-case is this: I know that a certain file (src/xterm.c in
Emacs) was modified on a certain date (Oct 8, 2010), and I want to see
the diffs for the corresponding revisions.  Easy enough, says I:

 bzr log -rdate:2010-10-08 src/xterm.c

To my surprise, this shows nothing.  Hmm...  Reading the docs more
carefully, I see that it says "-rdate:yesterday..", note the dots.
Aha!

 bzr log -rdate:2010-10-08.. src/xterm.c
 102487: Dan Nicolaescu 2010-11-23 Include <sys/ioctl.h> unconditionally.
 ...
 101865: Chong Yidong 2010-10-08 * xterm.c (x_draw_relief_rect): Clear corner...
 101845: Chong Yidong 2010-10-08 * xterm.c (x_draw_relief_rect): If box width...

Note that there are 2 revisions from 2010-10-08.  These are the ones I
want.  But I want only them.  So:

 bzr log -rdate:2010-10-07..date:2010-10-08 src/xterm.c

But this again comes up empty.  Hmm...  How about this then?

 bzr log -rdate:2010-10-07..date:2010-10-09 src/xterm.c
 101845: Chong Yidong 2010-10-08 * xterm.c (x_draw_relief_rect): If box width...

Only one of the two I wanted...  Okay, let's try this:

 bzr log -rdate:2010-10-07..date:2010-10-10 src/xterm.c
 101865: Chong Yidong 2010-10-08 * xterm.c (x_draw_relief_rect): Clear corner...
 101845: Chong Yidong 2010-10-08 * xterm.c (x_draw_relief_rect): If box width...

At last!  But why did I need to extend the date range by one more day,
when both changes show 2010-10-08 in the log results?

"bzr log -cdate:", which I thought would be The Right Thing, is even
worse.  Observe:

 bzr log -cdate:2010-10-07 src/xterm.c
 (Nothing)
 bzr log -cdate:2010-10-08 src/xterm.c
 (Nothing)
 bzr log -cdate:2010-10-09 src/xterm.c
 (Nothing)

Now, I realize that the docs (under revisionspec) says: "Matches the
first entry after a given date", "after" being the key word here.  So
"-cdate:" found a first revision _after_ the specified date, saw that
it didn't change src/xterm.c, and showed an empty list.  But can you
see how this is unhelpful, in the use-case I presented?  (Yes, I could
use "date:YYYY-MM-DD,HH:MM" to get what I want, but I only knew the
date, not the hour.)

To summarize:

  . there doesn't seem to be a good way of finding revisions of a
    single file when only a date is known; -rdate: seems to be useful
    mainly for showing revisions without selecting a file

  . there appears to be some issue with the date, in that dates shown
    in "bzr log"s output are somewhat inconsistent with -rdate:,
    perhaps due to time-zone issues

Did I miss something?  If not, can we have a more user-friendly way
for this use-case, please?