rust-dagops: roots
Unsuprisingly, the algorithm is much easier than for heads, provided
we work on a set in the first place.
To improve the signature, a trait for set-likes object would be useful,
but that's not an immediate concern.
Differential Revision: https://phab.mercurial-scm.org/D6230
[templates]
ldate = '{label("log.date",
"{date|isodate}")}'
ldesc = '{label('ui.note log.description',
'{desc|strip}')}'
ldescfirst = '{label('ui.note log.description',
'{desc|firstline|strip}')}'
changeset = '{lrev}{tags}{bookmarks}{parents} {lnode} {ldate} {luser}\n {ldescfirst}\n\n'
changeset_quiet = '{lrev}:{lnode}\n'
changeset_verbose = '{lrev}{tags}{parents} {lnode} {ldate} {lauthor}\n {ldesc}\n\n'
lrev = '{label("log.changeset changeset.{phase}",
"{rev}")}'
lnode = '{label("log.node",
"{node|short}")}'
lauthor = '{label("log.user",
"{author}")}'
luser = '{label("log.user",
"{author|user}")}'
start_tags = '['
tag = '{label("log.tag",
"{tag},")}'
last_tag = '{tag}]'
start_parents = ':'
parent = '{lrev},'
last_parent = '{lrev}'
start_bookmarks = '['
bookmark = '{label("log.bookmark",
"{bookmark},")}'
last_bookmark = '{bookmark}]'