repmgrd: ensure witness node metadata is updated

If the primary changed while the witness repmgrd was not running,
ensure the witness's upstream node ID is updated when the witness
repmgrd is restarted.

HISTORY

@@ -1,5 +1,8 @@
+5.4.1   2023-??-??
+        repmgrd: ensure witness node metadata is updated (Ian)
+
 5.4.0   2023-03-16
-	Support cloning replicas using pg-backup-api
+        Support cloning replicas using pg-backup-api
 
 5.3.3   2022-10-17
         Support for PostgreSQL added

doc/appendix-release-notes.xml

@@ -16,8 +16,29 @@
   </para>
 
   <!-- remember to update the release date in ../repmgr_version.h.in -->
+  <sect1 id="release-5.4.1">
+    <title id="release-current">Release 5.4.1</title>
+    <para><emphasis>??? ?? ??????, 202?</emphasis></para>
+    <para>
+      &repmgr; 5.4.1 is a minor release providing ...
+    </para>
+    <sect2>
+      <title>Bug fixes</title>
+      <para>
+        <itemizedlist>
+          <listitem>
+            <para>
+              &repmgrd;: ensure witness node metadata is updated if the primary
+              node changed while the witness &repmgrd; was not running.
+            </para>
+          </listitem>
+        </itemizedlist>
+      </para>
+    </sect2>
+  </sect1>
+
   <sect1 id="release-5.4.0">
-    <title id="release-current">Release 5.4.0</title>
+    <title>Release 5.4.0</title>
     <para><emphasis>Thu 15 March, 2023</emphasis></para>
     <para>
       &repmgr; 5.4.0 is a major release.
@@ -29,6 +50,7 @@
     <para>
       Minor fixes to the documentation.
     </para>
+  </sect1>
 
   <sect1 id="release-5.3.3">
     <title>Release 5.3.3</title>

repmgrd-physical.c

@@ -2394,6 +2394,17 @@ monitor_streaming_witness(void)
 			terminate(ERR_BAD_CONFIG);
 		}
 
+		/*
+		 * It's possible that the primary changed while the witness repmgrd was not
+		 * running. This does not affect the functionality of the witness repmgrd, but
+		 * does mean outdated node metadata will be displayed, so update that.
+		 */
+		if (local_node_info.upstream_node_id != primary_node_id)
+		{
+			update_node_record_set_upstream(primary_conn, local_node_info.node_id, primary_node_id);
+			local_node_info.upstream_node_id = primary_node_id;
+		}
+
 		initPQExpBuffer(&event_details);
 
 		appendPQExpBuffer(&event_details,