From 51a7f4bb7c9dd81a1f9bc54792aa212837fb267a Mon Sep 17 00:00:00 2001
From: Kegan Dougal <kegan@matrix.org>
Date: Tue, 7 Jul 2020 14:27:45 +0100
Subject: [PATCH] bugfix: continue sending PDUs if ones are added whilst
 sending another PDU

Without this, the queue goes back to sleep on `<-oq.notifyPDUs` which won't
fire because `pendingPDUs` is already > 0. This should fix a flakey sytest.
---
 federationsender/queue/destinationqueue.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/federationsender/queue/destinationqueue.go b/federationsender/queue/destinationqueue.go
index 1ad45254c..ab779a5d3 100644
--- a/federationsender/queue/destinationqueue.go
+++ b/federationsender/queue/destinationqueue.go
@@ -225,7 +225,7 @@ func (oq *destinationQueue) backgroundSend() {
 		}
 
 		// If we have pending PDUs or EDUs then construct a transaction.
-		if oq.pendingPDUs.Load() > 0 || len(oq.pendingEDUs) > 0 {
+		for oq.pendingPDUs.Load() > 0 || len(oq.pendingEDUs) > 0 {
 			// Try sending the next transaction and see what happens.
 			transaction, terr := oq.nextTransaction(oq.pendingEDUs)
 			if terr != nil {