From 6158d91b6f3b2c90960f9eaeec4a956049188ba2 Mon Sep 17 00:00:00 2001
From: Wiebe Cazemier <wiebe@halfgaar.net>
Date: Thu, 14 Apr 2022 21:11:26 +0200
Subject: [PATCH] Allow wills to be retained

---
 publishcopyfactory.cpp | 2 +-
 subscriptionstore.cpp  | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/publishcopyfactory.cpp b/publishcopyfactory.cpp
index df9c00f..d75044f 100644
--- a/publishcopyfactory.cpp
+++ b/publishcopyfactory.cpp
@@ -52,7 +52,7 @@ MqttPacket *PublishCopyFactory::getOptimumPacket(const char max_qos, const Proto
         return cachedPack.get();
     }
 
-    // Getting a packet of a Publish object happens on will messages and SYS topics and maybe some others. It's low traffic, anyway.
+    // Getting an instance of a Publish object happens at least on retained messages, will messages and SYS topics. It's low traffic, anyway.
     assert(publish);
 
     this->oneShotPacket = std::make_unique<MqttPacket>(protocolVersion, *publish);
diff --git a/subscriptionstore.cpp b/subscriptionstore.cpp
index 90d6466..9e99af9 100644
--- a/subscriptionstore.cpp
+++ b/subscriptionstore.cpp
@@ -312,6 +312,9 @@ void SubscriptionStore::sendQueuedWillMessages()
             PublishCopyFactory factory(p.get());
             queuePacketAtSubscribers(factory);
 
+            if (p->retain)
+                setRetainedMessage(*p.get(), (*p.get()).subtopics);
+
             s->clearWill();
         }
         it = pendingWillMessages.erase(it);
@@ -336,6 +339,9 @@ void SubscriptionStore::queueWillMessage(const std::shared_ptr<Publish> &willMes
         PublishCopyFactory factory(willMessage.get());
         queuePacketAtSubscribers(factory);
 
+        if (willMessage->retain)
+            setRetainedMessage(*willMessage.get(), (*willMessage.get()).subtopics);
+
         // Avoid sending two immediate wills when a session is destroyed with the client disconnect.
         if (session) // session is null when you're destroying a client before a session is assigned.
             session->clearWill();
@@ -518,6 +524,8 @@ uint64_t SubscriptionStore::giveClientRetainedMessages(const std::shared_ptr<Cli
 
 void SubscriptionStore::setRetainedMessage(const Publish &publish, const std::vector<std::string> &subtopics)
 {
+    assert(!subtopics.empty());
+
     RetainedMessageNode *deepestNode = &retainedMessagesRoot;
     if (!subtopics.empty() && !subtopics[0].empty() > 0 && subtopics[0][0] == '$')
         deepestNode = &retainedMessagesRootDollar;
--
libgit2 0.21.4