difftool: silence warning

Silence a warning given when running git difftool --dir-diff and
there are no changes.

This is because command_oneline returns undef when the command has no
output, not ''.

Signed-off-by: Ross Lagerwall <rosslagerwall@gmail.com>
Acked-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-difftool.perl b/git-difftool.perl
index 17d4de661820e8c7ae24694a21458be825b1ac9a..edd0493a08b501d60c04044e79a9e0b096d77953 100755 (executable)
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -138,7 +138,7 @@ sub setup_dir_diff
 
        my @gitargs = ('diff', '--raw', '--no-abbrev', '-z', @ARGV);
        my $diffrtn = $diffrepo->command_oneline(@gitargs);
-       exit(0) if (length($diffrtn) == 0);
+       exit(0) unless defined($diffrtn);
 
        # Build index info for left and right sides of the diff
        my $submodule_mode = '160000';