Improve box-stream passthrough goodbye

sbotc.c

@@ -553,6 +553,8 @@ static void bs_write_packet(struct boxs *bs, const unsigned char *buf, uint16_t
 }
 
 static void bs_end(struct boxs *bs) {
+	if (bs->wrote_goodbye) return;
+	bs->wrote_goodbye = true;
 	if (!bs->noauth) {
 		bs_write_end_box(bs);
 	}
@@ -615,7 +617,10 @@ static enum stream_state bs_read_out_1(struct boxs *bs, int fd) {
 	size_t len = sizeof(buf);
 	int rc;
 	rc = bs_read_packet(bs, buf, &len);
-	if (rc < 0 && errno == EPIPE) return stream_state_ended_ok;
+	if (rc < 0 && errno == EPIPE) {
+		bs_end(bs);
+		return stream_state_ended_ok;
+	}
 	if (rc < 0) return stream_state_ended_error;
 	rc = write_all(fd, buf, len);
 	if (rc < 0) return stream_state_ended_error;
@@ -746,7 +751,7 @@ static int bs_passthrough(struct boxs *bs, int infd, int outfd) {
 		if (FD_ISSET(sfd, &rd)) out = bs_read_out_1(bs, outfd);
 	}
 
-	return in == stream_state_ended_ok && out == stream_state_ended_ok ? 0 :
+	return in != stream_state_ended_error && out == stream_state_ended_ok ? 0 :
 	  in == stream_state_ended_error || out == stream_state_ended_error ? 2 : 1;
 }