fix panic (#769)

* fix panic
drand · Nov 11, 2020 · ddce47d · ddce47d
1 parent 32b601e
commit ddce47d
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/core/drand_control.go b/core/drand_control.go
@@ -798,7 +798,11 @@ func (d *Drand) StartFollowChain(req *drand.StartFollowRequest, stream drand.Con
 	d.state.Unlock()
 	defer func() {
 		d.state.Lock()
-		d.syncerCancel()
+		if d.syncerCancel != nil {
+			// it can be nil when we recreate a new beacon we cancel it
+			// see drand.go:newBeacon()
+			d.syncerCancel()
+		}
 		d.syncerCancel = nil
 		d.state.Unlock()
 	}()