ssh kitten: Fix a regression in 0.28.0 that caused interrupt during setup to not be handled gracefully

Fixes #6254

kittens/ssh/main.go

@@ -16,6 +16,7 @@ import (
 	"net/url"
 	"os"
 	"os/exec"
+	"os/signal"
 	"os/user"
 	"path"
 	"path/filepath"
@@ -669,6 +670,9 @@ func run_ssh(ssh_args, server_args, found_extra_args []string) (rc int, err erro
 	if err != nil {
 		return 1, err
 	}
+	sigs := make(chan os.Signal, 8)
+	signal.Notify(sigs, unix.SIGINT, unix.SIGTERM)
+
 	if !cd.request_data {
 		rq := fmt.Sprintf("id=%s:pwfile=%s:pw=%s", cd.replacements["REQUEST_ID"], cd.replacements["PASSWORD_FILENAME"], cd.replacements["DATA_PASSWORD"])
 		err := term.ApplyOperations(tty.TCSANOW, tty.SetNoEcho)
@@ -685,6 +689,11 @@ func run_ssh(ssh_args, server_args, found_extra_args []string) (rc int, err erro
 			return 1, err
 		}
 	}
+	go func() {
+		_ = <-sigs
+		// ignore any interrupt and terminate signals as they will usually be sent to the ssh child process as well
+		// and we are waiting on that.
+	}()
 	err = c.Wait()
 	drain_potential_tty_garbage(term)
 	if err != nil {