git-svn: Warn about changing default for --prefix in Git v2.0

In Git v2.0, we will change the default --prefix for init/clone from
none/empty to "origin/" (which causes SVN-tracking branches to be
placed at refs/remotes/origin/* instead of refs/remotes/*).

This patch warns users about the upcoming change, both in the git-svn
manual page, and on stderr when running init/clone in the "multi-mode"
without providing a --prefix.

Cc: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Eric Wong <normalperson@yhbt.net>

1 files changed, 11 insertions, 1 deletions

diff --git a/git-svn.perl b/git-svn.perl
index 1823db1..7349ffe 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -1389,7 +1389,17 @@ sub cmd_multi_init {
 		usage(1);
 	}
 
-	$_prefix = '' unless defined $_prefix;
+	unless (defined $_prefix) {
+		$_prefix = '';
+		warn <<EOF
+WARNING: --prefix is not given, defaulting to empty prefix.
+         This is probably not what you want! In order to stay compatible
+         with regular remote-tracking refs, provide a prefix like
+         --prefix=origin/ (remember the trailing slash), which will cause
+         the SVN-tracking refs to be placed at refs/remotes/origin/*.
+NOTE: In Git v2.0, the default prefix will change from empty to 'origin/'.
+EOF
+	}
 	if (defined $url) {
 		$url = canonicalize_url($url);
 		init_subdir(@_);