From 8f7a32a9a2cf5595a2b2a8968b5809ad9532afb3 Mon Sep 17 00:00:00 2001
From: Ian Barwick <ian@2ndquadrant.com>
Date: Tue, 17 Nov 2020 16:32:33 +0900
Subject: [PATCH] repmgr: prevent termination in corner-case situation

If neither the local node nor the upstream are available, and
"standby_disconnect_on_failover" is set, attempting to fetch
the walreceiver PID will result in repmgrd terminating.

Add a check that the connection is valid before attempting to
fetch the walreceiver PID.

Addresses GitHub #675.
---
 doc/appendix-release-notes.xml | 24 +++++++++++++++++++++++-
 sysutils.c                     |  6 ++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/doc/appendix-release-notes.xml b/doc/appendix-release-notes.xml
index 3eaabf5e..6dd4ee7f 100644
--- a/doc/appendix-release-notes.xml
+++ b/doc/appendix-release-notes.xml
@@ -15,10 +15,32 @@
     See also: <xref linkend="upgrading-repmgr"/>
   </para>
 
+  <sect1 id="release-5.2.1">
+    <title id="release-current">Release 5.2.1</title>
+    <para><emphasis>??? ?? ???, 2020</emphasis></para>
+
+    <para>
+      &repmgr; 5.2.1 is a minor release.
+    </para>
+    <sect2>
+      <title>Bug fixes</title>
+      <para>
+       <itemizedlist>
+          <listitem>
+            <para>
+              &repmgrd;: prevent termination when local node not available and
+              <option>standby_disconnect_on_failover</option> is set.  GitHub #675.
+            </para>
+          </listitem>
+       </itemizedlist>
+      </para>
+    </sect2>
+  </sect1>
+
 <!-- remember to update the release date in ../repmgr_version.h.in -->
 
   <sect1 id="release-5.2.0">
-    <title id="release-current">Release 5.2.0</title>
+    <title>Release 5.2.0</title>
     <para><emphasis>Thu 22 October, 2020</emphasis></para>
 
     <para>
diff --git a/sysutils.c b/sysutils.c
index 9ba78ebc..86051517 100644
--- a/sysutils.c
+++ b/sysutils.c
@@ -363,6 +363,12 @@ enable_wal_receiver(PGconn *conn, bool wait_startup)
 	/* make timeout configurable */
 	int i, timeout = 30;
 
+	if (PQstatus(conn) != CONNECTION_OK)
+	{
+		log_error(_("database connection not available"));
+		return UNKNOWN_PID;
+	}
+
 	if (is_superuser_connection(conn, NULL) == false)
 	{
 		log_error(_("superuser connection required"));