difftool: silence warning

rosslagerwall · gitster · commit ed36e5bd41f7 · 2012-08-21T15:27:15.000-07:00
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 &lt;rosslagerwall@gmail.com&gt;
Acked-by: David Aguilar &lt;davvid@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git 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';
