git-svn: fix "Malformed network data" with svn:// servers

We have a workaround for the reparent function not working
correctly on the SVN native protocol servers.  This workaround
opens a new connection (SVN::Ra object) to the new
URL/directory.

Since libsvn appears limited to only supporting one connection
at a time, this workaround invalidates the Git::SVN::Ra object
that is $self inside gs_fetch_loop_common().  So we need to
restart that connection once all the fetching is done for each
loop iteration to be able to run get_log() successfully.
Signed-off-by: NEric Wong <normalperson@yhbt.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

git-svn.perl

@@ -3013,7 +3013,7 @@ package Git::SVN::Ra;
 use vars qw/@ISA $config_dir $_log_window_size/;
 use strict;
 use warnings;
-my ($can_do_switch, %ignored_err, $RA);
+my ($ra_invalid, $can_do_switch, %ignored_err, $RA);
 
 BEGIN {
 	# enforce temporary pool usage for some simple functions
@@ -3174,7 +3174,11 @@ sub gs_do_switch {
 			$self->{url} = $full_url;
 			$reparented = 1;
 		} else {
+			$_[0] = undef;
+			$self = undef;
+			$RA = undef;
 			$ra = Git::SVN::Ra->new($full_url);
+			$ra_invalid = 1;
 		}
 	}
 	$ra ||= $self;
@@ -3234,6 +3238,7 @@ sub gs_fetch_loop_common {
 	my $inc = $_log_window_size;
 	my ($min, $max) = ($base, $head < $base + $inc ? $head : $base + $inc);
 	my $longest_path = longest_common_path($gsv, $globs);
+	my $ra_url = $self->{url};
 	while (1) {
 		my %revs;
 		my $err;
@@ -3295,6 +3300,13 @@ sub gs_fetch_loop_common {
 				        "$g->{t}-maxRev";
 				Git::SVN::tmp_config($k, $r);
 			}
+			if ($ra_invalid) {
+				$_[0] = undef;
+				$self = undef;
+				$RA = undef;
+				$self = Git::SVN::Ra->new($ra_url);
+				$ra_invalid = undef;
+			}
 		}
 		# pre-fill the .rev_db since it'll eventually get filled in
 		# with '0' x40 if something new gets committed