From 68bd52920ce6043678f6d19d1f221930e7a214d5 Mon Sep 17 00:00:00 2001
From: Pete Batard <pete@akeo.ie>
Date: Wed, 27 Nov 2013 22:02:55 +0000
Subject: [PATCH] Windows: Fix a crash when HID transfers return no data

* Issue reported by Surmakyynis
* Closes #160
---
 libusb/os/windows_usb.c | 26 ++++++++++++++------------
 libusb/version_nano.h   |  2 +-
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/libusb/os/windows_usb.c b/libusb/os/windows_usb.c
index b11cb93..aa4c0f4 100644
--- a/libusb/os/windows_usb.c
+++ b/libusb/os/windows_usb.c
@@ -4161,19 +4161,21 @@ static int hid_copy_transfer_data(int sub_api, struct usbi_transfer *itransfer,
 	if (transfer_priv->hid_buffer != NULL) {
 		// If we have a valid hid_buffer, it means the transfer was async
 		if (transfer_priv->hid_dest != NULL) {	// Data readout
-			// First, check for overflow
-			if (corrected_size > transfer_priv->hid_expected_size) {
-				usbi_err(ctx, "OVERFLOW!");
-				corrected_size = (uint32_t)transfer_priv->hid_expected_size;
-				r = LIBUSB_TRANSFER_OVERFLOW;
-			}
+			if (corrected_size > 0) {
+				// First, check for overflow
+				if (corrected_size > transfer_priv->hid_expected_size) {
+					usbi_err(ctx, "OVERFLOW!");
+					corrected_size = (uint32_t)transfer_priv->hid_expected_size;
+					r = LIBUSB_TRANSFER_OVERFLOW;
+				}
 
-			if (transfer_priv->hid_buffer[0] == 0) {
-				// Discard the 1 byte report ID prefix
-				corrected_size--;
-				memcpy(transfer_priv->hid_dest, transfer_priv->hid_buffer+1, corrected_size);
-			} else {
-				memcpy(transfer_priv->hid_dest, transfer_priv->hid_buffer, corrected_size);
+				if (transfer_priv->hid_buffer[0] == 0) {
+					// Discard the 1 byte report ID prefix
+					corrected_size--;
+					memcpy(transfer_priv->hid_dest, transfer_priv->hid_buffer+1, corrected_size);
+				} else {
+					memcpy(transfer_priv->hid_dest, transfer_priv->hid_buffer, corrected_size);
+				}
 			}
 			transfer_priv->hid_dest = NULL;
 		}
diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index e9bdb4e..d88c0cc 100644
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 10850
+#define LIBUSB_NANO 10851
-- 
2.7.4