rhg: add RootCommand using hg-core FindRoot operation to prepare `hg root`
The println macro is not used to avoid string usage.
Dealing only with bytes allows us to be compatible with any encoding
and not just UTF8.
Later on, format macro will be made to have more readable code.
Differential Revision: https://phab.mercurial-scm.org/D8612
Issue1678: IndexError when pushing
setting up base repo
$ hg init a
$ cd a
$ touch a
$ hg ci -Am a
adding a
$ cd ..
cloning base repo
$ hg clone a b
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd b
setting up cset to push
$ hg up null
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ touch a
different msg so we get a clog new entry
$ hg ci -Am b
adding a
created new head
pushing
$ hg push -f ../a
pushing to ../a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files (+1 heads)
$ cd ..