From b0570ad6e50ab4c1daa7d3e735e82251816379dc Mon Sep 17 00:00:00 2001
From: "Masih H. Derkani" <m@derkani.org>
Date: Mon, 18 Dec 2023 21:10:58 +0000
Subject: [PATCH] Check for zero valued progress

---
 exchange/fx_exchange.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/exchange/fx_exchange.go b/exchange/fx_exchange.go
index fd076dde..e2a1a79b 100644
--- a/exchange/fx_exchange.go
+++ b/exchange/fx_exchange.go
@@ -318,7 +318,10 @@ func (e *FxExchange) Push(ctx context.Context, to peer.ID, l ipld.Link) error {
 	}
 	// Recursively traverse the node and push all its leaves.
 	err = traversal.WalkAdv(node, exploreAllRecursivelySelector, func(progress traversal.Progress, node datamodel.Node, _ traversal.VisitReason) error {
-		log := log.With("t-cid", progress.LastBlock.Link.(cidlink.Link).Cid)
+		log := log
+		if progress.LastBlock.Link != nil {
+			log = log.With("t-cid", progress.LastBlock.Link.(cidlink.Link).Cid)
+		}
 		var buf bytes.Buffer
 		err := dagcbor.Encode(node, &buf)
 		if err != nil {