From 45f7640d2aec2a4da13134f6716e07426cdc75be Mon Sep 17 00:00:00 2001
From: Sadie Powell
Date: Mon, 9 Sep 2024 12:11:05 +0100
Subject: Send an ISupport diff when a user moves to a new connect class.

---
 src/coremods/core_info/core_info.cpp | 11 +++++++++++
 src/coremods/core_info/core_info.h   |  7 +++++++
 src/coremods/core_info/isupport.cpp  | 17 +++++++++++++++++
 src/coremods/core_user/core_user.cpp |  5 +++++
 4 files changed, 40 insertions(+)

(limited to 'src')

diff --git a/src/coremods/core_info/core_info.cpp b/src/coremods/core_info/core_info.cpp
index 347850b0d..c6baa71aa 100644
--- a/src/coremods/core_info/core_info.cpp
+++ b/src/coremods/core_info/core_info.cpp
@@ -169,6 +169,17 @@ public:
 		ServerInstance->AtomicActions.AddAction(new ISupportAction(isupport));
 	}
 
+	void OnChangeConnectClass(LocalUser* user, const std::shared_ptr<ConnectClass>& klass, bool force) override
+	{
+		// TODO: this should be OnPostChangeConnectClass but we need the old
+		// connect class which isn't exposed to the module interface and we
+		// can't break the API in a stable release. For now we use this and
+		// prioritise it to be after core_user checks whether the user needs
+		// to die.
+		if (user->IsFullyConnected() && !user->quitting)
+			isupport.ChangeClass(user, user->GetClass(), klass);
+	}
+
 	void OnUserConnect(LocalUser* user) override
 	{
 		user->WriteNumeric(RPL_WELCOME, INSP_FORMAT("Welcome to the {} IRC Network {}", ServerInstance->Config->Network, user->GetRealMask()));
diff --git a/src/coremods/core_info/core_info.h b/src/coremods/core_info/core_info.h
index ca5ba8590..9baad8fb0 100644
--- a/src/coremods/core_info/core_info.h
+++ b/src/coremods/core_info/core_info.h
@@ -59,6 +59,13 @@ public:
 	 */
 	void Build();
 
+	/** Sends an 005 (ISUPPORT) diff from the old class to the new one.
+	 * @param user The user to send the diff to.
+	 * @param oldclass The connect class the user is moving from.
+	 * @param newclass The conenct class the user is moving to.
+	 */
+	void ChangeClass(LocalUser* user, const std::shared_ptr<ConnectClass>& oldclass, const std::shared_ptr<ConnectClass>& newclass);
+
 	/** Send the 005 numerics (ISUPPORT) to a user.
 	 * @param user The user to send the ISUPPORT numerics to
 	 */
diff --git a/src/coremods/core_info/isupport.cpp b/src/coremods/core_info/isupport.cpp
index be9f645af..b9f275ec3 100644
--- a/src/coremods/core_info/isupport.cpp
+++ b/src/coremods/core_info/isupport.cpp
@@ -160,6 +160,23 @@ void ISupportManager::BuildNumerics(ISupport::TokenMap& tokens, std::vector<Nume
 	}
 }
 
+void ISupportManager::ChangeClass(LocalUser* user, const std::shared_ptr<ConnectClass>& oldclass, const std::shared_ptr<ConnectClass>& newclass)
+{
+	auto oldtokens = cachedtokens.find(oldclass);
+	auto newtokens = cachedtokens.find(newclass);
+	if (oldtokens == cachedtokens.end() || newtokens == cachedtokens.end())
+		return; // Should never happen.
+
+	ISupport::TokenMap difftokens;
+	TokenDifference(difftokens, oldtokens->second, newtokens->second);
+
+	std::vector<Numeric::Numeric> diffnumerics;
+	BuildNumerics(difftokens, diffnumerics);
+
+	for (const auto& numeric : diffnumerics)
+		user->WriteNumeric(numeric);
+}
+
 void ISupportManager::SendTo(LocalUser* user)
 {
 	auto numerics = cachednumerics.find(user->GetClass());
diff --git a/src/coremods/core_user/core_user.cpp b/src/coremods/core_user/core_user.cpp
index 20f679862..273c982cb 100644
--- a/src/coremods/core_user/core_user.cpp
+++ b/src/coremods/core_user/core_user.cpp
@@ -280,6 +280,11 @@ public:
 		const auto& performance = ServerInstance->Config->ConfValue("performance");
 		clonesonconnect = performance->getBool("clonesonconnect", true);
 	}
+
+	void Prioritize() override
+	{
+		ServerInstance->Modules.SetPriority(this, I_OnChangeConnectClass, PRIORITY_FIRST);
+	}
 };
 
 MODULE_INIT(CoreModUser)
-- 
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