contrib/xml.rnc

filemerge: make `_maketempfiles()` more reusable

`_maketempfiles()` is very specialized for its current use. I hope to
use it also when creating temporary files for input for tools that do
partial conflict resolution. That'll be possible if the function is
more generic. Instead of passing in two contexts (for "other" and
"base") and an optional path (for "local"), let's pass a single list
of files to make backups for. Even if we don't end up using for
partial conflict resolution, this is still a simplification (but I do
have a WIP patch for partial conflict resolution and it is able to
benefit from this).

Differential Revision: https://phab.mercurial-scm.org/D12193

# 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}