revset: added min and max methods to baseset and lazyset
This classes have no particular order so they rely on python min() and max()
implementation. This methods will be implemented in every smartset class in
future patches. For other classes there are lazy implementations that can be
made for this methods.
$ hg init a
$ cd a
$ echo 123 > a
$ hg add a
$ hg commit -m "a" -u a
$ cd ..
$ hg init b
$ cd b
$ echo 321 > b
$ hg add b
$ hg commit -m "b" -u b
$ hg pull ../a
pulling from ../a
searching for changes
abort: repository is unrelated
[255]
$ hg pull -f ../a
pulling from ../a
searching for changes
warning: repository is unrelated
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg heads
changeset: 1:9a79c33a9db3
tag: tip
parent: -1:000000000000
user: a
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
changeset: 0:01f8062b2de5
user: b
date: Thu Jan 01 00:00:00 1970 +0000
summary: b
$ cd ..