From 4a9ef121231c3e8b5f3cfdec97fcf42946f32688 Mon Sep 17 00:00:00 2001
From: TeoV <teofil.voivozeanu@itsyscom.com>
Date: Sun, 30 Aug 2020 14:54:47 +0300
Subject: [PATCH] Exit automatic debit loops if debitStop channel was nil-led,
 fixes #2354

---
 sessions/sessions.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sessions/sessions.go b/sessions/sessions.go
index eb1c893cd..fff5f8ac3 100644
--- a/sessions/sessions.go
+++ b/sessions/sessions.go
@@ -520,6 +520,11 @@ func (sS *SessionS) debitLoopSession(s *Session, sRunIdx int,
 	}
 	for {
 		s.Lock()
+		if s.debitStop == nil {
+			// session already closed (most probably from sessionEnd), fixes concurrency
+			s.Unlock()
+			return
+		}
 		var maxDebit time.Duration
 		if maxDebit, err = sS.debitSession(s, sRunIdx, dbtIvl, nil); err != nil {
 			utils.Logger.Warning(