Don't set a new pgrp if the terminal already controls the tty

src/main.rs

@@ -132,6 +132,9 @@ fn parse_args() -> CommandLineArgs {
 
 fn set_unique_pid() -> nix::Result<()> {
     let pgid = unistd::getpid();
+    if pgid == unistd::tcgetpgrp(nix::libc::STDIN_FILENO)? {
+        return Ok(());
+    }
     unistd::setpgid(pgid, pgid)?;
     unsafe { signal::signal(Signal::SIGTTOU, SigHandler::SigIgn) }?;
     unistd::tcsetpgrp(nix::libc::STDIN_FILENO, pgid)