From 7b7ff7e8abcd63afd47adbc5d1092717f1bb66c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20G=C3=B6m=C3=B6ri?= <peter@84codes.com>
Date: Sat, 11 Nov 2023 00:36:56 +0100
Subject: [PATCH] Classic queue: discard rejected msg even when
 publisher-confirm disabled

Otherwise the message is never removed from the state of mirrored queue
slaves.

Fixes #9905
---
 deps/rabbit/src/rabbit_amqqueue_process.erl | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/deps/rabbit/src/rabbit_amqqueue_process.erl b/deps/rabbit/src/rabbit_amqqueue_process.erl
index 7f21b9a06399..347bb373e41a 100644
--- a/deps/rabbit/src/rabbit_amqqueue_process.erl
+++ b/deps/rabbit/src/rabbit_amqqueue_process.erl
@@ -816,6 +816,7 @@ send_reject_publish(#delivery{confirm = true,
                                   backing_queue = BQ,
                                   backing_queue_state = BQS,
                                   msg_id_to_channel   = MTC}) ->
+    %% Drop publish and nack to publisher
     MsgId = mc:get_annotation(id, Msg),
     ok = rabbit_classic_queue:send_rejection(SenderPid,
                                              amqqueue:get_name(Q), MsgSeqNo),
@@ -823,9 +824,20 @@ send_reject_publish(#delivery{confirm = true,
     MTC1 = maps:remove(MsgId, MTC),
     BQS1 = BQ:discard(MsgId, SenderPid, Flow, BQS),
     State#q{ backing_queue_state = BQS1, msg_id_to_channel = MTC1 };
-send_reject_publish(#delivery{confirm = false},
-                      _Delivered, State) ->
-    State.
+send_reject_publish(#delivery{confirm = false,
+                              sender = SenderPid,
+                              flow = Flow,
+                              message = Msg},
+                    _Delivered,
+                    State = #q{q = Q,
+                               backing_queue = BQ,
+                               backing_queue_state = BQS,
+                               msg_id_to_channel = MTC}) ->
+    %% Only drop publish
+    MsgId = mc:get_annotation(id, Msg),
+    MTC1 = maps:remove(MsgId, MTC),
+    BQS1 = BQ:discard(MsgId, SenderPid, Flow, BQS),
+    State#q{ backing_queue_state = BQS1, msg_id_to_channel = MTC1 }.
 
 will_overflow(_, #q{max_length = undefined,
                     max_bytes  = undefined}) -> false;