From 7162c656ccf246be20ded423cd0b889dafbd24be Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Tue, 25 Apr 2023 11:56:26 -0700
Subject: [PATCH] fix: chain: record heaviest tipset before notifying (#10694)

Clearly this hasn't caused any issues, but I'm pretty sure we should be
updating the current head _before_ notifying about it.
---
 chain/store/store.go | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/chain/store/store.go b/chain/store/store.go
index b34ddb266..dc9dc6484 100644
--- a/chain/store/store.go
+++ b/chain/store/store.go
@@ -639,22 +639,10 @@ func (cs *ChainStore) reorgWorker(ctx context.Context, initialNotifees []ReorgNo
 func (cs *ChainStore) takeHeaviestTipSet(ctx context.Context, ts *types.TipSet) error {
 	_, span := trace.StartSpan(ctx, "takeHeaviestTipSet")
 	defer span.End()
-
-	if cs.heaviest != nil { // buf
-		if len(cs.reorgCh) > 0 {
-			log.Warnf("Reorg channel running behind, %d reorgs buffered", len(cs.reorgCh))
-		}
-		cs.reorgCh <- reorg{
-			old: cs.heaviest,
-			new: ts,
-		}
-	} else {
-		log.Warnf("no heaviest tipset found, using %s", ts.Cids())
-	}
-
 	span.AddAttributes(trace.BoolAttribute("newHead", true))
 
 	log.Infof("New heaviest tipset! %s (height=%d)", ts.Cids(), ts.Height())
+	prevHeaviest := cs.heaviest
 	cs.heaviest = ts
 
 	if err := cs.writeHead(ctx, ts); err != nil {
@@ -662,6 +650,18 @@ func (cs *ChainStore) takeHeaviestTipSet(ctx context.Context, ts *types.TipSet)
 		return err
 	}
 
+	if prevHeaviest != nil { // buf
+		if len(cs.reorgCh) > 0 {
+			log.Warnf("Reorg channel running behind, %d reorgs buffered", len(cs.reorgCh))
+		}
+		cs.reorgCh <- reorg{
+			old: prevHeaviest,
+			new: ts,
+		}
+	} else {
+		log.Warnf("no previous heaviest tipset found, using %s", ts.Cids())
+	}
+
 	return nil
 }