contrib/xml.rnc

mergestate: determine if active without looking for state files on disk

I couldn't think of a reason that we need to check state files on disk
to determine if a merge is active. I could imagine them being for
there for detecting broken state files that would then be cleaned up
by some later command, but we always delete the entire `.hg/merge/`
tree, so that doesn't seem to be it.

The checks were added in 4e932dc5c113 (resolve: abort when not
applicable (BC), 2014-04-18). Perhaps there were needed for that and
then made obsolete by 6062593d8b06 (resolve: don't abort resolve -l
even when no merge is in progress, 2014-05-23).

The reason I want to delete the checks is that I think `ms =
mergestate.read(repo); ms.active() and ms.local` should be a valid
pattern, but it crashes when the merge state file is an empty file if
we consider mere presence of the file as "active".

Differential Revision: https://phab.mercurial-scm.org/D8118

# RelaxNG schema for "xml" log style
# Inspired by Subversion's XML log format.

start = log
node.type = xsd:string  {minLength = "40" maxLength = "40"}

log = element log { logentry+ }
logentry = element logentry {
    logentry.attlist,
    branch*, tag*, hgparent*,
    author, date,
    msg, paths?, copies?, extra*
}
logentry.attlist =
    attribute revision {xsd:nonNegativeInteger}
  & attribute node {node.type}
branch = element branch { text }
tag = element tag { text }
hgparent = element parent {hgparent.attlist, text}
hgparent.attlist =
    attribute revision {xsd:integer {minInclusive = "-1"} }
  & attribute node {node.type}
author = element author { author.attlist, text }
author.attlist =
    attribute email {text}
date = element date {xsd:dateTime}
msg = element msg {msg.attlist, text}
msg.attlist =
    attribute xml:space {"preserve"}
paths = element paths { path* }
path = element path { path.attlist, text }
path.attlist =
    # Action: (A)dd, (M)odify, (R)emove
    attribute action {"A"|"M"|"R"}
copies = element copies { copy+ }
copy = element copy { copy.attlist, text }
copy.attlist =
    attribute source {text}
extra = element extra {extra.attlist, text}
extra.attlist =
    attribute key {text}