From 75d9b72475708ee0da13fb23ef65dcced805b6af Mon Sep 17 00:00:00 2001
From: stickies-v <stickies-v@protonmail.com>
Date: Fri, 5 Sep 2025 15:46:44 +0100
Subject: [PATCH] kernel: make blockTip index const

Notification interface subscribers need to view, but not mutate,
the index.
---
 src/bitcoin-chainstate.cpp           | 2 +-
 src/kernel/notifications_interface.h | 2 +-
 src/node/kernel_notifications.cpp    | 2 +-
 src/node/kernel_notifications.h      | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/bitcoin-chainstate.cpp b/src/bitcoin-chainstate.cpp
index 4ac6a6f41a1..46e6f06e27f 100644
--- a/src/bitcoin-chainstate.cpp
+++ b/src/bitcoin-chainstate.cpp
@@ -74,7 +74,7 @@ int main(int argc, char* argv[])
     class KernelNotifications : public kernel::Notifications
     {
     public:
-        kernel::InterruptResult blockTip(SynchronizationState, CBlockIndex&, double) override
+        kernel::InterruptResult blockTip(SynchronizationState, const CBlockIndex&, double) override
         {
             std::cout << "Block tip changed" << std::endl;
             return {};
diff --git a/src/kernel/notifications_interface.h b/src/kernel/notifications_interface.h
index 3e97e3b45e9..816f06307be 100644
--- a/src/kernel/notifications_interface.h
+++ b/src/kernel/notifications_interface.h
@@ -37,7 +37,7 @@ class Notifications
 public:
     virtual ~Notifications() = default;
 
-    [[nodiscard]] virtual InterruptResult blockTip(SynchronizationState state, CBlockIndex& index, double verification_progress) { return {}; }
+    [[nodiscard]] virtual InterruptResult blockTip(SynchronizationState state, const CBlockIndex& index, double verification_progress) { return {}; }
     virtual void headerTip(SynchronizationState state, int64_t height, int64_t timestamp, bool presync) {}
     virtual void progress(const bilingual_str& title, int progress_percent, bool resume_possible) {}
     virtual void warningSet(Warning id, const bilingual_str& message) {}
diff --git a/src/node/kernel_notifications.cpp b/src/node/kernel_notifications.cpp
index 4a6f8444dac..56c7188ac1a 100644
--- a/src/node/kernel_notifications.cpp
+++ b/src/node/kernel_notifications.cpp
@@ -48,7 +48,7 @@ static void AlertNotify(const std::string& strMessage)
 
 namespace node {
 
-kernel::InterruptResult KernelNotifications::blockTip(SynchronizationState state, CBlockIndex& index, double verification_progress)
+kernel::InterruptResult KernelNotifications::blockTip(SynchronizationState state, const CBlockIndex& index, double verification_progress)
 {
     {
         LOCK(m_tip_block_mutex);
diff --git a/src/node/kernel_notifications.h b/src/node/kernel_notifications.h
index 10ee3e18d74..21d2ea43241 100644
--- a/src/node/kernel_notifications.h
+++ b/src/node/kernel_notifications.h
@@ -35,7 +35,7 @@ public:
     KernelNotifications(const std::function<bool()>& shutdown_request, std::atomic<int>& exit_status, node::Warnings& warnings)
         : m_shutdown_request(shutdown_request), m_exit_status{exit_status}, m_warnings{warnings} {}
 
-    [[nodiscard]] kernel::InterruptResult blockTip(SynchronizationState state, CBlockIndex& index, double verification_progress) override EXCLUSIVE_LOCKS_REQUIRED(!m_tip_block_mutex);
+    [[nodiscard]] kernel::InterruptResult blockTip(SynchronizationState state, const CBlockIndex& index, double verification_progress) override EXCLUSIVE_LOCKS_REQUIRED(!m_tip_block_mutex);
 
     void headerTip(SynchronizationState state, int64_t height, int64_t timestamp, bool presync) override;