view contrib/xml.rnc @ 13206:650314ed845d stable

windows.rename: eliminate temp name race (issue2571)

On Windows, os.rename reliably raises OSError with errno.EEXIST if the
destination already exists (even on shares served by Samba).

Windows does *not* silently overwrite the destination of a rename.

So there is no need to first call os.path.exists on the chosen temp path.

Trusting os.path.exists is actually harmful, since using it enables the
following racy sequence of actions:

 1) os.path.exists(temp) returns False
 2) some evil other process creates a file with name temp
 3) os.rename(dst, temp) now fails because temp has been taken

Not using os.path.exists and directly trying os.rename(dst, temp)
eliminates this race.

# 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}