3 files changed, 27 insertions, 9 deletions

diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 3826e82c052..32a1575ab07 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -218,7 +218,7 @@ WalReceiverMain(void)
 
 	/* Fetch information required to start streaming */
 	strlcpy(conninfo, (char *) walrcv->conninfo, MAXCONNINFO);
-	startpoint = walrcv->receivedUpto;
+	startpoint = walrcv->receiveStart;
 	SpinLockRelease(&walrcv->mutex);
 
 	/* Arrange to clean up at walreceiver exit */
@@ -558,8 +558,11 @@ XLogWalRcvFlush(bool dying)
 
 		/* Update shared-memory status */
 		SpinLockAcquire(&walrcv->mutex);
-		walrcv->latestChunkStart = walrcv->receivedUpto;
-		walrcv->receivedUpto = LogstreamResult.Flush;
+		if (XLByteLT(walrcv->receivedUpto, LogstreamResult.Flush))
+		{
+			walrcv->latestChunkStart = walrcv->receivedUpto;
+			walrcv->receivedUpto = LogstreamResult.Flush;
+		}
 		SpinLockRelease(&walrcv->mutex);
 
 		/* Signal the startup process that new WAL has arrived */
diff --git a/src/backend/replication/walreceiverfuncs.c b/src/backend/replication/walreceiverfuncs.c
index 04c90049437..48ab503d893 100644
--- a/src/backend/replication/walreceiverfuncs.c
+++ b/src/backend/replication/walreceiverfuncs.c
@@ -199,8 +199,17 @@ RequestXLogStreaming(XLogRecPtr recptr, const char *conninfo)
 	walrcv->walRcvState = WALRCV_STARTING;
 	walrcv->startTime = now;
 
-	walrcv->receivedUpto = recptr;
-	walrcv->latestChunkStart = recptr;
+	/*
+	 * If this is the first startup of walreceiver, we initialize
+	 * receivedUpto and latestChunkStart to receiveStart.
+	 */
+	if (walrcv->receiveStart.xlogid == 0 &&
+		walrcv->receiveStart.xrecoff == 0)
+	{
+		walrcv->receivedUpto = recptr;
+		walrcv->latestChunkStart = recptr;
+	}
+	walrcv->receiveStart = recptr;
 
 	SpinLockRelease(&walrcv->mutex);
 
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 9137b861c7d..775232b6e6f 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -52,11 +52,17 @@ typedef struct
 	pg_time_t	startTime;
 
 	/*
+	 * receiveStart is the first byte position that will be received.
+	 * When startup process starts the walreceiver, it sets receiveStart
+	 * to the point where it wants the streaming to begin.
+	 */
+	XLogRecPtr	receiveStart;
+
+	/*
 	 * receivedUpto-1 is the last byte position that has already been
-	 * received.  When startup process starts the walreceiver, it sets
-	 * receivedUpto to the point where it wants the streaming to begin. After
-	 * that, walreceiver updates this whenever it flushes the received WAL to
-	 * disk.
+	 * received.  At the first startup of walreceiver, receivedUpto is
+	 * set to receiveStart. After that, walreceiver updates this whenever
+	 * it flushes the received WAL to disk.
 	 */
 	XLogRecPtr	receivedUpto;