Run the catch-up at the controller's start and after each merge it hears (ADR 0457, issue 1336)

cmd/mesh-controller/push.go

@@ -208,6 +208,8 @@ func serve(ctx context.Context) (err error) {
 	if err := server.Follows(following{open: open}); err != nil {
 		return err
 	}
+	// And the merges it did not hear while it was away, caught up once it serves (novox/hq ADR 0457, issue 1336).
+	go catchUpAtStart(ctx, open)
 	// And the merges mesh-delivery made, kept a week with the ask each was made on: what registers a module that
 	// moved between repositories on the operator's Approve (novox/hq ADR 0420 §7, issue 1025).
 	if err := server.KeepsDeliveryMerges(keepingDeliveryMerges{js: server.JetStream, catalog: open.inventory.Catalogued,

cmd/mesh-controller/upgrades.go

@@ -316,7 +316,16 @@ func unsaved(err error) error {
 // SourceMoved is the forge announcing a merge. It is put into the open batch (novox/hq ADR 0276), which
 // becomes one walk when its merge window closes: hearMerge, and cutBatchesHeld in batches.go.
 func (f following) SourceMoved(ctx context.Context, m link.SourceMoved) error {
-	return f.hearMerge(ctx, m, time.Now().UTC())
+	if err := f.hearMerge(ctx, m, time.Now().UTC()); err != nil {
+		return err
+	}
+	// And the merges of that trunk it did not hear, in the trunk's order (novox/hq ADR 0457): a catch-up that leaves
+	// something for later is no failure of this merge's hearing, and is never a reason to hear it again.
+	if !f.oneShot {
+		trunk := &caughtTrunk{Owner: m.Owner, Repo: m.Repo, Branch: m.Base}
+		catchUpBeside(func() { f.catchUp(context.WithoutCancel(ctx), trunk) })
+	}
+	return nil
 }
 
 // movesOfMerge is what one merge moves, acted on: every module recorded as built from that repository and