git-svn: avoid crashing svnserve when creating new directories

When sorting directory names by depth (slash ("/") count) and
closing the deepest directories first (as the protocol
requires), we failed to put the root baton (with an empty string
as its key "") after top-level directories (which did not have
any slashes).

This resulted in svnserve being in a situation it couldn't
handle and caused a segmentation fault on the remote server.

This bug did not affect users of DAV and filesystem repositories.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Confirmed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <junkio@cox.net>

git-svn.perl

@@ -2841,8 +2841,10 @@ sub close_edit {
 	my ($self) = @_;
 	my ($p,$bat) = ($self->{pool}, $self->{bat});
 	foreach (sort { $b =~ tr#/#/# <=> $a =~ tr#/#/# } keys %$bat) {
+		next if $_ eq '';
 		$self->close_directory($bat->{$_}, $p);
 	}
+	$self->close_directory($bat->{''}, $p);
 	$self->SUPER::close_edit($p);
 	$p->clear;
 }