Fix pg_receivexlog --synchronous

Make pg_receivexlog work correctly with --synchronous without slots

Backpatch to 9.5

Gabriele Bartolini, reviewed by Michael Paquier and Simon Riggs

diff --git a/src/bin/pg_basebackup/receivelog.c b/src/bin/pg_basebackup/receivelog.c
index 595213f0420f524d8600b376b53faa8a085246c5..062730b6b43b5a85580a5087d36fb4966e66fa19 100644 (file)
--- a/src/bin/pg_basebackup/receivelog.c
+++ b/src/bin/pg_basebackup/receivelog.c
@@ -503,26 +503,28 @@ ReceiveXlogStream(PGconn *conn, StreamCtl *stream)
    if (!CheckServerVersionForStreaming(conn))
        return false;
 
+   /*
+    * Decide whether we want to report the flush position. If we report
+    * the flush position, the primary will know what WAL we'll
+    * possibly re-request, and it can then remove older WAL safely.
+    * We must always do that when we are using slots.
+    *
+    * Reporting the flush position makes one eligible as a synchronous
+    * replica. People shouldn't include generic names in
+    * synchronous_standby_names, but we've protected them against it so
+    * far, so let's continue to do so unless specifically requested.
+    */
    if (replication_slot != NULL)
    {
-       /*
-        * Report the flush position, so the primary can know what WAL we'll
-        * possibly re-request, and remove older WAL safely.
-        *
-        * We only report it when a slot has explicitly been used, because
-        * reporting the flush position makes one eligible as a synchronous
-        * replica. People shouldn't include generic names in
-        * synchronous_standby_names, but we've protected them against it so
-        * far, so let's continue to do so in the situations when possible. If
-        * they've got a slot, though, we need to report the flush position,
-        * so that the master can remove WAL.
-        */
        reportFlushPosition = true;
        sprintf(slotcmd, "SLOT \"%s\" ", replication_slot);
    }
    else
    {
-       reportFlushPosition = false;
+       if (stream->synchronous)
+           reportFlushPosition = true;
+       else
+           reportFlushPosition = false;
        slotcmd[0] = 0;
    }