fix: commands on SSH hosts run under sh -c, so hosts whose login shell is csh or tcsh list, zip and send files too

internal/agent/ship.go

@@ -562,6 +562,14 @@ func (u *unpacker) own(p string) {
 // shq quotes s for a POSIX shell.
 func shq(s string) string { return "'" + strings.ReplaceAll(s, "'", `'\''`) + "'" }
 
+// posix wraps a command for the host's sh: the user's login shell gets one
+// word to hand on, so fish or csh there does not matter.
+func posix(cmd string) string {
+	// csh reads "!" as history even inside single quotes; '\!' is a plain
+	// "!" for it and for sh alike.
+	return "sh -c " + strings.ReplaceAll(shq(cmd), "!", `'\!'`)
+}
+
 // shipSSH writes the tar stream into tar on the SSH host, in Dir.
 func (a *Agent) shipSSH(ctx context.Context, args proto.FSShipArgs, src string, m *shipMeter) error {
 	client, _, err := a.sshConnect(ctx, *args.SSH, func(_, note string) { m.note.Store(note) })
@@ -615,7 +623,7 @@ func (a *Agent) shipSSH(ctx context.Context, args proto.FSShipArgs, src string,
 		return err
 	}
 	cmd := "mkdir -p -- " + shq(dir) + " && cd -- " + shq(dir) + " && tar -xf -" + flags
-	if err := sess.Start(cmd); err != nil {
+	if err := sess.Start(posix(cmd)); err != nil {
 		return err
 	}
 	m.note.Store("")
@@ -646,7 +654,7 @@ func sshRun(c *ssh.Client, cmd string) (string, error) {
 		return "", err
 	}
 	defer s.Close()
-	out, err := s.Output(cmd)
+	out, err := s.Output(posix(cmd))
 	var ee *ssh.ExitError
 	if errors.As(err, &ee) {
 		err = nil // the checks may exit non-zero; what they print is the answer