From: Uwe Hermann <redacted>
Date: Thu, 12 Apr 2018 07:02:38 +0000 (+0200)
Subject: can: Fix incorrect stuff bit handling.
X-Git-Url: http://sigrok.org/gitweb/?p=libsigrokdecode.git;a=commitdiff_plain;h=cffb6592f4cff804745b8456e2c9f8abc6571603

can: Fix incorrect stuff bit handling.

The decoder assumed a CRC cannot end with a stuffed bit but it actually can,
and the CRC delimiter then comes after the stuffed bit.

Patch by IRC/github user celeron55, wide testing by PeterMortensen, thanks!
---

diff --git a/decoders/can/pd.py b/decoders/can/pd.py
index 056736b..d76d649 100644
--- a/decoders/can/pd.py
+++ b/decoders/can/pd.py
@@ -132,7 +132,7 @@ class Decoder(srd.Decoder):
         # CAN uses NRZ encoding and bit stuffing.
         # After 5 identical bits, a stuff bit of opposite value is added.
         # But not in the CRC delimiter, ACK, and end of frame fields.
-        if len(self.bits) > self.last_databit + 16:
+        if len(self.bits) > self.last_databit + 17:
             return False
         last_6_bits = self.rawbits[-6:]
         if last_6_bits not in ([0, 0, 0, 0, 0, 1], [1, 1, 1, 1, 1, 0]):