git-svn: support intermediate paths when matching tags/branches

For repositories laid out like the following:

[svn-remote "svn"]
      url = http://foo.com/svn/repos/bar
      fetch = myproject/trunk:refs/remotes/trunk
      branches = bar/myproject/branches/*:refs/remotes/*
      tags = bar/myproject/tags/*:refs/remotes/tags/*

The "bar" component above is considered the intermediate path
and was not handled correctly.

Signed-off-by: Michael Lai <myllai@gmail.com>
Acked-by: Eric Wong <normalperson@yhbt.net>
diff --git a/git-svn.perl b/git-svn.perl
index 959eb52..8be6be0 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -2351,7 +2351,10 @@
 	if (my $path = $paths->{"/$self->{path}"}) {
 		return ($path->{action} eq 'D') ? 0 : 1;
 	}
-	$self->{path_regex} ||= qr/^\/\Q$self->{path}\E\//;
+	my $repos_root = $self->ra->{repos_root};
+	my $extended_path = $self->{url} . '/' . $self->{path};
+	$extended_path =~ s#^\Q$repos_root\E(/|$)##;
+	$self->{path_regex} ||= qr/^\/\Q$extended_path\E\//;
 	if (grep /$self->{path_regex}/, keys %$paths) {
 		return 1;
 	}