[PATCH/rfc] git-svn.perl: workaround assertions in svn library 1.5.0

With subversion 1.5.0 (C and perl libraries) the git-svn selftest
t9101-git-svn-props.sh fails at test 25 and 26.  The following commands
cause assertions in the svn library

 $ cd deeply
 $ git-svn propget svn:ignore .
 perl: /build/buildd/subversion-1.5.0dfsg1/subversion/libsvn_ra/ra_loader.c:674: svn_ra_get_dir: Assertion `*path != '/'' failed.
 Aborted

 $ git-svn propget svn:ignore ..
 perl: /build/buildd/subversion-1.5.0dfsg1/subversion/libsvn_subr/path.c:120: svn_path_join: Assertion `is_canonical(component, clen)' failed.

With this commit, git-svn makes sure the path doesn't start with a
slash, and is not a dot, working around these assertions.

The breakage was reported by Lucas Nussbaum through
 http://bugs.debian.org/489108

Signed-off-by: Gerrit Pape <redacted>
---
 git-svn.perl |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

I ran into this on Debian/unstable.  With svn 1.5.0 the selftest fails
without the patch, with svn 1.4.6 it succeeds with and without the
patch.  I'm not familar with the svn interfaces, not sure whether this
is a regression in subversion, or a bug in git-svn.

diff --git a/git-svn.perl b/git-svn.perl
index f789a6e..a366c89 100755
--- a/git-svn.perl
+++ b/git-svn.perl

@@ -643,6 +643,8 @@ sub canonicalize_path {
 	$path =~ s#/[^/]+/\.\.##g;
 	$path =~ s#/$##g;
 	$path =~ s#^\./## if $dot_slash_added;
+	$path =~ s#^/##;
+	$path =~ s#^\.$##;
 	return $path;
 }
 

-- 
1.5.6