Handle array response in parallell with pubsub using RESP3 (#1014)

RESP3 allows sending commands in parallell with pubsub handling
and these commands might get responded with a REDIS_REPLY_ARRAY.
This conflicts with the pubsub response handling for RESP2 and
results in a faulty state when using RESP3.

Add functionality to keep track of PUSH/RESP3 support on the connection
and only expect the message type REDIS_REPLY_PUSH as subscribe messages
when once seen.

1 files changed, 4 insertions, 1 deletions

diff --git a/async.c b/async.c
index 389ba2b..e855bf7 100644
--- a/async.c
+++ b/async.c
@@ -420,7 +420,7 @@ static int __redisGetSubscribeCallback(redisAsyncContext *ac, redisReply *reply,
     /* Match reply with the expected format of a pushed message.
      * The type and number of elements (3 to 4) are specified at:
      * https://redis.io/topics/pubsub#format-of-pushed-messages */
-    if ((reply->type == REDIS_REPLY_ARRAY && reply->elements >= 3) ||
+    if ((reply->type == REDIS_REPLY_ARRAY && !(c->flags & REDIS_SUPPORTS_PUSH) && reply->elements >= 3) ||
         reply->type == REDIS_REPLY_PUSH) {
         assert(reply->element[0]->type == REDIS_REPLY_STRING);
         stype = reply->element[0]->str;
@@ -525,6 +525,9 @@ void redisProcessCallbacks(redisAsyncContext *ac) {
             break;
         }
 
+        /* Keep track of push message support for subscribe handling */
+        if (redisIsPushReply(reply)) c->flags |= REDIS_SUPPORTS_PUSH;
+
         /* Send any non-subscribe related PUSH messages to our PUSH handler
          * while allowing subscribe related PUSH messages to pass through.
          * This allows existing code to be backward compatible and work in