init: Delay RPC block notif until warmup finished

See added code comment for more details.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 0c5baeee3b..9c8963d10d 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1777,7 +1777,17 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
     // ********************************************************* Step 13: finished
 
+    // At this point, the RPC is "started", but still in warmup, which means it
+    // cannot yet be called. Before we make it callable, we need to make sure
+    // that the RPC's view of the best block is valid and consistent with
+    // ChainstateManager's ActiveTip.
+    //
+    // If we do not do this, RPC's view of the best block will be height=0 and
+    // hash=0x0. This will lead to erroroneous responses for things like
+    // waitforblockheight.
+    RPCNotifyBlockChange(chainman.ActiveTip());
     SetRPCWarmupFinished();
+
     uiInterface.InitMessage(_("Done loading").translated);
 
     for (const auto& client : node.chain_clients) {