help: reuse print_columns() for help -a

diff --git a/builtin/merge.c b/builtin/merge.c
index ed0f959ac49c02aaffa77bc748a9efc69f1fd339..d3e1e8dc9e478aaea7ef4da855fb7c2e10397644 100644 (file)
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1129,7 +1129,7 @@ static int default_edit_option(void)
        /* Use editor if stdin and stdout are the same and is a tty */
        return (!fstat(0, &st_stdin) &&
                !fstat(1, &st_stdout) &&
-               isatty(0) &&
+               isatty(0) && isatty(1) &&
                st_stdin.st_dev == st_stdout.st_dev &&
                st_stdin.st_ino == st_stdout.st_ino &&
                st_stdin.st_mode == st_stdout.st_mode);