git-svn: fix log command to avoid infinite loop on long commit messages

This bug has been around since the the conversion to use the
Git.pm library back in October or November.  Eventually I'd like
"git rev-list/log" to have the option to not truncate overly
long messages.
Signed-off-by: NEric Wong <normalperson@yhbt.net>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

git-svn.perl

@@ -3263,12 +3263,19 @@ package Git::SVN::Log;
 sub cmt_showable {
 	my ($c) = @_;
 	return 1 if defined $c->{r};
+
+	# big commit message got truncated by the 16k pretty buffer in rev-list
 	if ($c->{l} && $c->{l}->[-1] eq "...\n" &&
 				$c->{a_raw} =~ /\@([a-f\d\-]+)>$/) {
+		@{$c->{l}} = ();
 		my @log = command(qw/cat-file commit/, $c->{c});
-		shift @log while ($log[0] ne "\n");
+
+		# shift off the headers
+		shift @log while ($log[0] ne '');
 		shift @log;
-		@{$c->{l}} = grep !/^git-svn-id: /, @log;
+
+		# TODO: make $c->{l} not have a trailing newline in the future
+		@{$c->{l}} = map { "$_\n" } grep !/^git-svn-id: /, @log;
 
 		(undef, $c->{r}, undef) = ::extract_metadata(
 				(grep(/^git-svn-id: /, @log))[-1]);