From 1811223a253dbcfc0cd3c18097d2a573be21c73e Mon Sep 17 00:00:00 2001
From: Jing Ma <mjing@google.com>
Date: Sun, 20 Dec 2020 00:22:20 +0800
Subject: [PATCH] [thread-cert] fix case 7.1.6 intermittent failure (#5974)

An issue is caused by tiny time difference as well between step 5 and
step 6, step 6 occasionally is sent out ahead of step5.
---
 .../Cert_7_1_06_BorderRouterAsLeader.py       | 55 ++++++++++---------
 1 file changed, 28 insertions(+), 27 deletions(-)

diff --git a/tests/scripts/thread-cert/Cert_7_1_06_BorderRouterAsLeader.py b/tests/scripts/thread-cert/Cert_7_1_06_BorderRouterAsLeader.py
index 249398299..089864663 100755
--- a/tests/scripts/thread-cert/Cert_7_1_06_BorderRouterAsLeader.py
+++ b/tests/scripts/thread-cert/Cert_7_1_06_BorderRouterAsLeader.py
@@ -245,33 +245,34 @@ class Cert_7_1_6_BorderRouterAsLeader(thread_cert.TestCase):
                    p.thread_nwd.tlv.prefix
                    ).\
             must_next()
-        _dr_pkt1 = pkts.filter_wpan_src64(LEADER).\
-            filter_LLANMA().\
-            filter_mle_cmd(MLE_DATA_RESPONSE).\
-            filter(lambda p: {
-                              NETWORK_DATA_TLV,
-                              SOURCE_ADDRESS_TLV,
-                              LEADER_DATA_TLV
-                             } <= set(p.mle.tlv.type) and\
-                             {
-                              NWD_BORDER_ROUTER_TLV,
-                              NWD_BORDER_ROUTER_TLV,
-                              NWD_6LOWPAN_ID_TLV
-                             } <= set(p.thread_nwd.tlv.type) and\
-                   p.thread_nwd.tlv.border_router.flag.p == [1, 1] and\
-                   p.thread_nwd.tlv.border_router.flag.s == [1, 1] and\
-                   p.thread_nwd.tlv.border_router.flag.r == [1, 1] and\
-                   p.thread_nwd.tlv.border_router.flag.o == [1, 1] and\
-                   p.mle.tlv.leader_data.data_version ==
-                   (_dr_pkt.mle.tlv.leader_data.data_version + 1) % 256 and\
-                   (p.mle.tlv.leader_data.stable_data_version ==
-                    (_dr_pkt.mle.tlv.leader_data.stable_data_version + 1) % 256 or\
-                   p.mle.tlv.leader_data.stable_data_version ==
-                    (_pkt.mle.tlv.leader_data.stable_data_version + 1) % 256) and\
-                   [Ipv6Addr(PREFIX_2001[:-3])] ==
-                   p.thread_nwd.tlv.prefix
-                   ).\
-            must_next()
+        with pkts.save_index():
+            _dr_pkt1 = pkts.filter_wpan_src64(LEADER).\
+                filter_LLANMA().\
+                filter_mle_cmd(MLE_DATA_RESPONSE).\
+                filter(lambda p: {
+                                  NETWORK_DATA_TLV,
+                                  SOURCE_ADDRESS_TLV,
+                                  LEADER_DATA_TLV
+                                 } <= set(p.mle.tlv.type) and\
+                                 {
+                                  NWD_BORDER_ROUTER_TLV,
+                                  NWD_BORDER_ROUTER_TLV,
+                                  NWD_6LOWPAN_ID_TLV
+                                 } <= set(p.thread_nwd.tlv.type) and\
+                       p.thread_nwd.tlv.border_router.flag.p == [1, 1] and\
+                       p.thread_nwd.tlv.border_router.flag.s == [1, 1] and\
+                       p.thread_nwd.tlv.border_router.flag.r == [1, 1] and\
+                       p.thread_nwd.tlv.border_router.flag.o == [1, 1] and\
+                       p.mle.tlv.leader_data.data_version ==
+                       (_dr_pkt.mle.tlv.leader_data.data_version + 1) % 256 and\
+                       (p.mle.tlv.leader_data.stable_data_version ==
+                        (_dr_pkt.mle.tlv.leader_data.stable_data_version + 1) % 256 or\
+                       p.mle.tlv.leader_data.stable_data_version ==
+                        (_pkt.mle.tlv.leader_data.stable_data_version + 1) % 256) and\
+                       [Ipv6Addr(PREFIX_2001[:-3])] ==
+                       p.thread_nwd.tlv.prefix
+                       ).\
+                must_next()
 
         # Step 6: Leader MUST send a MLE Child Update Request or MLE Data
         #         Response to SED, including the following TLVs: