From f6c1bba3b6c4ddce1670d81aa47fbf715d819a4a Mon Sep 17 00:00:00 2001
From: James Shubin <james@shubin.ca>
Date: Tue, 26 Jul 2016 01:58:13 -0400
Subject: [PATCH] Avoid a rare panic if DestroyServer is called early

I never actually hit this bug, but I noticed it was possible when
examining the WaitGroup code that gets .Done() by DestroyServer().
---
 etcd.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/etcd.go b/etcd.go
index 94d94306..1a763869 100644
--- a/etcd.go
+++ b/etcd.go
@@ -1589,6 +1589,9 @@ func (obj *EmbdEtcd) DestroyServer() error {
 	log.Printf("Etcd: DestroyServer: Done removing data...")
 
 	obj.memberId = 0
+	if obj.server == nil { // skip the .Done() below because we didn't .Add(1) it.
+		return err
+	}
 	obj.server = nil // important because this is used as an isRunning flag
 	log.Printf("Etcd: DestroyServer: Unlocking server...")
 	obj.serverwg.Done() // -1