From: robertl <robertl@f51c46e8-681c-474f-0cfe-069cfd0219fb>
Date: Tue, 16 Nov 2004 03:50:19 +0000 (+0000)
Subject: Suppress zero byte writes for benefit of Bob Anderson's Keyspan USB/Serial adapter.
X-Git-Tag: archive/raspbian/1.10.0+ds-2+rpi1~1^2~12^2~11^2~3862
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=18ac70847a792de2cffe4f7077fd669fa5af3aa8;p=gpsbabel.git

Suppress zero byte writes for benefit of Bob Anderson's Keyspan USB/Serial adapter.
---

diff --git a/gpsbabel/jeeps/gpsserial.c b/gpsbabel/jeeps/gpsserial.c
index b2a51bb22..f7d5d631a 100644
--- a/gpsbabel/jeeps/gpsserial.c
+++ b/gpsbabel/jeeps/gpsserial.c
@@ -180,6 +180,17 @@ int32 GPS_Serial_Flush(int32 fd)
 int32 GPS_Serial_Write(int32 ignored, const void *obuf, int size)
 {
 	DWORD len;
+
+	/* 
+	 * Unbelievably, the Keyspan PDA serial driver 3.2, a "Windows 
+	 * Certified driver", will crash the OS on a write of zero bytes.
+	 * We get such writes from upstream when there are zero payload
+	 * bytes.  SO we trap those here to stop Keyspan & Windows from
+	 * nuking the system.
+	 */
+	if (size == 0) {
+		return 0;
+	}
 	WriteFile (comport, obuf, size, &len, NULL);
 	if (len != size) {
 		fatal ("Write error.   Wrote %d of %d bytes.", len, size);