convert: correctly convert paths to UTF-8 for Subversion
The previous code using encoding.tolocal() only worked by chance in these
situations:
* The string is ASCII: The fast path was triggered and the string was returned
unmodified.
* The local encoding is UTF-8: The source and target encoding is the same.
* The string is not valid UTF-8 and the native encoding is ISO-8859-1: If the
string doesn’t decode using UTF-8, ISO-8859-1 is tried as a fallback. During
`hg convert`, the local encoding is always UTF-8. The irony is that in this
case, encoding.tolocal() behaves like what someone would expect the reverse
function, encoding.fromlocal(), to do.
When the locale encoding is ISO-8859-15, trying to convert a SVN repo `/tmp/a€`
failed before like this:
file:///tmp/a%C2%A4 does not look like a Subversion repository to libsvn version 1.14.0
The correct URL is `file:///tmp/a%E2%82%AC`.
Unlike previously (with the ISO-8859-1 fallback), decoding the path using the
locale encoding can fail. In this case, we have to bail out, as Subversion
won’t be able to do anything useful with the path.
# Dummy extension to define a namespace containing revision names
from __future__ import absolute_import
from mercurial import namespaces
def reposetup(ui, repo):
names = {b'r%d' % rev: repo[rev].node() for rev in repo}
namemap = lambda r, name: names.get(name)
nodemap = lambda r, node: [b'r%d' % repo[node].rev()]
ns = namespaces.namespace(
b'revnames',
templatename=b'revname',
logname=b'revname',
listnames=lambda r: names.keys(),
namemap=namemap,
nodemap=nodemap,
)
repo.names.addnamespace(ns)