From 73b53024cbf83e3393f848185eb9bc429b0699b8 Mon Sep 17 00:00:00 2001
From: vyzo <vyzo@hackzen.org>
Date: Fri, 21 Jan 2022 09:48:46 +0200
Subject: [PATCH] move semaphore before opening stream in sendDelta

---
 p2p/protocol/identify/peer_loop.go | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/p2p/protocol/identify/peer_loop.go b/p2p/protocol/identify/peer_loop.go
index c2dc4581fb..828f106473 100644
--- a/p2p/protocol/identify/peer_loop.go
+++ b/p2p/protocol/identify/peer_loop.go
@@ -115,17 +115,17 @@ func (ph *peerHandler) sendDelta(ctx context.Context) error {
 		return nil
 	}
 
-	ph.ids.pushSemaphore <- struct{}{}
-	defer func() {
-		<-ph.ids.pushSemaphore
-	}()
-
 	// extract a delta message, updating the last state.
 	mes := ph.nextDelta()
 	if mes == nil || (len(mes.AddedProtocols) == 0 && len(mes.RmProtocols) == 0) {
 		return nil
 	}
 
+	ph.ids.pushSemaphore <- struct{}{}
+	defer func() {
+		<-ph.ids.pushSemaphore
+	}()
+
 	ds, err := ph.openStream(ctx, []string{IDDelta})
 	if err != nil {
 		return fmt.Errorf("failed to open delta stream: %w", err)