rfc: log -r-5..-1 output when branch contains less than 5 revisions

[Alexander Belchenko]

It's somewhat rare question. But I'd like to hear some comments.

In the time when some branch initialized from ground and have few
commits behaviour of log when requested revisions with -N form is
somewhat discouraging. Bzr says that branch has no revision 0 (-1, -2,
-3, etc). Yes, it is not. But when user request revision in negative
form user specify not absolute but relative revisions numbers. Why not
trunkate this request to first existent revision? When log printed revno
information is printed too. So when user request 5 last revisions but
output contain less revisions (e.g. only 3 revisions) it could figure
out that branch contain too few revisions. I guess so.

This question is grows based on John Meinel's shortlog plugin and work
of Aaron Bentley for make defaults options for commands.

--
Alexander