From 3289a59a41c367755359feb7d39632eb8283ce0f Mon Sep 17 00:00:00 2001
From: TeoV <teofil.voivozeanu@itsyscom.com>
Date: Mon, 31 Aug 2020 09:31:59 +0300
Subject: [PATCH] Exit automatic debit loops if debitStop channel was nil-led

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

diff --git a/sessions/sessions.go b/sessions/sessions.go
index ccf9cc490..54d001be7 100644
--- a/sessions/sessions.go
+++ b/sessions/sessions.go
@@ -472,6 +472,11 @@ 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(