git svn: always reuse existing remotes on fetch

The internal no_reuse_existing flag is set to allow initializing
multiple remotes with the same URL, common with SVM users.

Unfortunately, this flag caused misbehavior when used
with the -R command-line flag for fetching.

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

git-svn.perl

@@ -428,6 +428,7 @@ sub cmd_fetch {
 	if (@_ > 1) {
 		die "Usage: $0 fetch [--all] [--parent] [svn-remote]\n";
 	}
+	$Git::SVN::no_reuse_existing = undef;
 	if ($_fetch_parent) {
 		my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
 		unless ($gs) {
@@ -956,6 +957,7 @@ sub cmd_multi_init {
 }
 
 sub cmd_multi_fetch {
+	$Git::SVN::no_reuse_existing = undef;
 	my $remotes = Git::SVN::read_all_remotes();
 	foreach my $repo_id (sort keys %$remotes) {
 		if ($remotes->{$repo_id}->{url}) {