Fixed USART reception overrun corrupting the internal buffers in the USBtoSerial project.

LUFA/DoxygenPages/ChangeLog.txt

@@ -24,6 +24,7 @@
   *  - Library Applications:
   *   - Fixed spurious 0xFE USART byte sent in the USBtoSerial project when the baud rate is changed (thanks to Carl Kjeldsen)
   *   - Fixed blocking USART reads causing low throughput on slow baud rates in the USBtoSerial project (thanks to Nevada Smith)
+  *   - Fixed USART reception overrun corrupting the internal buffers in the USBtoSerial project (thanks to Nevada Smith)
   *
   *  \section Sec_ChangeLog140302 Version 140302
   *  <b>New:</b>

Projects/USBtoSerial/USBtoSerial.c

@@ -194,7 +194,7 @@ ISR(USART1_RX_vect, ISR_BLOCK)
 {
 	uint8_t ReceivedByte = UDR1;
 
-	if (USB_DeviceState == DEVICE_STATE_Configured)
+	if ((USB_DeviceState == DEVICE_STATE_Configured) && !(RingBuffer_IsFull(&USARTtoUSB_Buffer)))
 	  RingBuffer_Insert(&USARTtoUSB_Buffer, ReceivedByte);
 }