difftool: exit(0) when usage is printed

diff --git a/git-difftool.perl b/git-difftool.perl
index 93e84e8d3da8a88d6517a5174e650cf102343542..4555cd8b1c5b8cda4527b328b858a015ac75d357 100755 (executable)
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -20,6 +20,7 @@
 
 sub usage
 {
+       my $exitcode = shift;
        print << 'USAGE';
 usage: git difftool [-t|--tool=<tool>]
                     [-x|--extcmd=<cmd>]
@@ -27,7 +28,7 @@ sub usage
                     [--prompt] [-y|--no-prompt]
                     ['git diff' options]
 USAGE
-       exit 1;
+       exit($exitcode);
 }
 
 sub setup_environment
@@ -58,14 +59,14 @@ sub exe
        'x|extcmd:s' => \$extcmd);
 
 if (defined($help)) {
-       usage();
+       usage(0);
 }
 if (defined($difftool_cmd)) {
        if (length($difftool_cmd) > 0) {
                $ENV{GIT_DIFF_TOOL} = $difftool_cmd;
        } else {
                print "No <tool> given for --tool=<tool>\n";
-               usage();
+               usage(1);
        }
 }
 if (defined($extcmd)) {
@@ -73,7 +74,7 @@ sub exe
                $ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
        } else {
                print "No <cmd> given for --extcmd=<cmd>\n";
-               usage();
+               usage(1);
        }
 }
 if ($gui) {