From 8bd5e391020cb9d5992d3d30cb5f85ead6b15c95 Mon Sep 17 00:00:00 2001
From: yvette903 <49490087+yvette903@users.noreply.github.com>
Date: Tue, 15 Jun 2021 14:21:52 +0800
Subject: [PATCH] Fix coredump after Client Unpause command when threaded I/O
 is enabled (#9041)

Fix crash when using io-threads-do-reads and issuing CLIENT PAUSE and
CLIENT UNPAUSE.
This issue was introduced in redis 6.2 together with the FAILOVER command.

(cherry picked from commit 096c5fd5d22caa2c21a4863cbaaf64fd8e7107d2)
---
 src/networking.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/networking.c b/src/networking.c
index 9de105982..d59e49592 100644
--- a/src/networking.c
+++ b/src/networking.c
@@ -3654,7 +3654,7 @@ int postponeClientRead(client *c) {
     if (server.io_threads_active &&
         server.io_threads_do_reads &&
         !ProcessingEventsWhileBlocked &&
-        !(c->flags & (CLIENT_MASTER|CLIENT_SLAVE|CLIENT_PENDING_READ)))
+        !(c->flags & (CLIENT_MASTER|CLIENT_SLAVE|CLIENT_PENDING_READ|CLIENT_BLOCKED))) 
     {
         c->flags |= CLIENT_PENDING_READ;
         listAddNodeHead(server.clients_pending_read,c);
@@ -3718,6 +3718,7 @@ int handleClientsWithPendingReadsUsingThreads(void) {
         c->flags &= ~CLIENT_PENDING_READ;
         listDelNode(server.clients_pending_read,ln);
 
+        serverAssert(!(c->flags & CLIENT_BLOCKED));
         if (processPendingCommandsAndResetClient(c) == C_ERR) {
             /* If the client is no longer valid, we avoid
              * processing the client later. So we just go