message when starting standby without setting restore_command

Hello.

When I tried to start server just putting recovery.signal, I got
the following message.

> FATAL:  must specify restore_command when standby mode is not enabled

I got a bit confused to see the message. Formerly this message
was shown when recovery.conf that is setting standby_mode to yes
doesn't have restore_command setting. But now we can put
recovery.signal separately from standby.signal. I think this
message ought not to mention standby mode.

FATAL:  must specify restore_command to start in targeted recovery mode

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center
From 6bd8e6fd75e1adc2007b90d787145184845692d7 Mon Sep 17 00:00:00 2001
From: Kyotaro Horiguchi <horiguchi.kyotaro@lab.ntt.co.jp>
Date: Thu, 4 Apr 2019 12:51:54 +0900
Subject: [PATCH] Rewrite an error message for targeted recovery mode

Formerly the message was shown when recovery.conf that is setting
standby_mode to yes doesn't have restore_command setting. Now standby
mode is not a part of recovery setting so the message ought to be
written not mentioning "standby mode".
---
 src/backend/access/transam/xlog.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index a181e33dd4..6e9901bd5e 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -5367,7 +5367,7 @@ validateRecoveryParameters(void)
             strcmp(recoveryRestoreCommand, "") == 0)
             ereport(FATAL,
                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-                     errmsg("must specify restore_command when standby mode is not enabled")));
+                     errmsg("must specify restore_command to start in targeted recovery mode")));
     }
 
     /*
-- 
2.16.3