From ae8cb8ab462de3ce7952b8b688c7a3b4e654a11f Mon Sep 17 00:00:00 2001
From: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Date: Tue, 4 Aug 2020 17:24:06 +0200
Subject: [PATCH] ftdi_bmp: Reject writes with no data.

Pending transfers made the MPSSE behaviour strange and unpredictable.
---
 src/platforms/hosted/ftdi_bmp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/platforms/hosted/ftdi_bmp.c b/src/platforms/hosted/ftdi_bmp.c
index f78ab4ce..7ff6485e 100644
--- a/src/platforms/hosted/ftdi_bmp.c
+++ b/src/platforms/hosted/ftdi_bmp.c
@@ -455,6 +455,8 @@ bool libftdi_srst_get_val(void)
 
 void libftdi_buffer_flush(void)
 {
+	if (!bufptr)
+		return;
 	DEBUG_WIRE("Flush\n");
 #if defined(USE_USB_VERSION_BIT)
 static struct ftdi_transfer_control *tc_write = NULL;