t9801: check git-p4's branch detection with client spec enabled

diff --git a/git-difftool.perl b/git-difftool.perl
index 18ca61e8d0493bde9c21ed337043bc72fa5c73a7..7df7c8a9a7c889fbf5f0b2d6e67be66bf6fea6b1 100755 (executable)
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -47,13 +47,9 @@ sub find_worktree
 
 sub print_tool_help
 {
-       my $cmd = 'TOOL_MODE=diff';
-       $cmd .= ' && . "$(git --exec-path)/git-mergetool--lib"';
-       $cmd .= ' && show_tool_help';
-
        # See the comment at the bottom of file_diff() for the reason behind
        # using system() followed by exit() instead of exec().
-       my $rc = system('sh', '-c', $cmd);
+       my $rc = system(qw(git mergetool --tool-help=diff));
        exit($rc | ($rc >> 8));
 }
 
@@ -346,6 +342,7 @@ sub main
                symlinks => $^O ne 'cygwin' &&
                                $^O ne 'MSWin32' && $^O ne 'msys',
                tool_help => undef,
+               trust_exit_code => undef,
        );
        GetOptions('g|gui!' => \$opts{gui},
                'd|dir-diff' => \$opts{dirdiff},
@@ -356,6 +353,8 @@ sub main
                'no-symlinks' => sub { $opts{symlinks} = 0; },
                't|tool:s' => \$opts{difftool_cmd},
                'tool-help' => \$opts{tool_help},
+               'trust-exit-code' => \$opts{trust_exit_code},
+               'no-trust-exit-code' => sub { $opts{trust_exit_code} = 0; },
                'x|extcmd:s' => \$opts{extcmd});
 
        if (defined($opts{help})) {
@@ -387,6 +386,15 @@ sub main
                }
        }
 
+       if (!defined $opts{trust_exit_code}) {
+               $opts{trust_exit_code} = Git::config_bool('difftool.trustExitCode');
+       }
+       if ($opts{trust_exit_code}) {
+               $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'true';
+       } else {
+               $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'false';
+       }
+
        # In directory diff mode, 'git-difftool--helper' is called once
        # to compare the a/b directories.  In file diff mode, 'git diff'
        # will invoke a separate instance of 'git-difftool--helper' for