git-svn: give show-ignore HEAD smarts, like dcommit and log

This allows the user to run git-svn show-ignore on there
current HEAD without needing to remember which branch/ref they
branched from with -i.  Also, find_by_url should correctly
handle cases where the URL passed to it is not valid.

Signed-off-by: Eric Wong <normalperson@yhbt.net>

diff --git a/git-svn.perl b/git-svn.perl
index dc78dcf8cf801f01b2cc191e3fb8053d148c9561..b4e8966919e67bc8aff3235aa2cd3da706dc928a 100755 (executable)
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -425,7 +425,8 @@ sub cmd_rebase {
 }
 
 sub cmd_show_ignore {
-       my $gs = Git::SVN->new;
+       my $url = (::working_head_info('HEAD'))[0];
+       my $gs = Git::SVN->find_by_url($url) || Git::SVN->new;
        my $r = (defined $_revision ? $_revision : $gs->ra->get_latest_revnum);
        $gs->traverse_ignore(\*STDOUT, '', $r);
 }
@@ -1034,6 +1035,7 @@ sub init_remote_config {
 
 sub find_by_url { # repos_root and, path are optional
        my ($class, $full_url, $repos_root, $path) = @_;
+       return undef unless defined $full_url;
        my $remotes = read_all_remotes();
        if (defined $full_url && defined $repos_root && !defined $path) {
                $path = $full_url;