Enforce session timeout even if coordinator connection is down

CHANGELOG.md

@@ -76,6 +76,9 @@ librdkafka v1.6.0 is feature release:
    a number of edge cases for the consumer where the behaviour was previously
    undefined.
  * Partition fetch state was not set to STOPPED if OffsetCommit failed.
+ * The session timeout is now enforced locally also when the coordinator
+   connection is down, which was not previously the case.
+
 
 ### Producer fixes
 

src/rdkafka_cgrp.c

@@ -4945,9 +4945,6 @@ static void rd_kafka_cgrp_join_state_serve (rd_kafka_cgrp_t *rkcg) {
 		break;
 
         case RD_KAFKA_CGRP_JOIN_STATE_STEADY:
-                if (rd_kafka_cgrp_session_timeout_check(rkcg, now))
-                        return;
-                /* FALLTHRU */
         case RD_KAFKA_CGRP_JOIN_STATE_WAIT_ASSIGN_CALL:
         case RD_KAFKA_CGRP_JOIN_STATE_WAIT_UNASSIGN_CALL:
                 if (rkcg->rkcg_flags & RD_KAFKA_CGRP_F_SUBSCRIPTION &&
@@ -4993,6 +4990,11 @@ void rd_kafka_cgrp_serve (rd_kafka_cgrp_t *rkcg) {
         if (unlikely(rd_kafka_terminating(rkcg->rkcg_rk)))
                 return;
 
+        /* Check session timeout regardless of current coordinator
+         * connection state (rkcg_state) */
+        if (rkcg->rkcg_join_state == RD_KAFKA_CGRP_JOIN_STATE_STEADY)
+                rd_kafka_cgrp_session_timeout_check(rkcg, now);
+
  retry:
         switch (rkcg->rkcg_state)
         {