Do not create new timeline for replica promotion (#746)

Co-authored-by: Konstantin Knizhnik <konstantin.knizhnik@databricks.com>

Author: 2 people

src/backend/access/transam/xlog.c

@@ -6128,7 +6128,7 @@ StartupXLOG(void)
 	 * In a normal crash recovery, we can just extend the timeline we were in.
 	 */
 	newTLI = endOfRecoveryInfo->lastRecTLI;
-	if (ArchiveRecoveryRequested)
+	if (ArchiveRecoveryRequested && !NeonRecoveryRequested)
 	{
 		newTLI = findNewestTimeLine(recoveryTargetTLI) + 1;
 		ereport(LOG,

src/backend/access/transam/xlogrecovery.c

@@ -1707,29 +1707,33 @@ FinishWalRecovery(void)
 
 			XLogPageHeader xlogPageHdr = (XLogPageHeader) (page);
 
-			xlogPageHdr->xlp_pageaddr = pageBeginPtr;
-			xlogPageHdr->xlp_magic = XLOG_PAGE_MAGIC;
-			xlogPageHdr->xlp_tli = recoveryTargetTLI;
-			/*
-			 * If we start writing with offset from page beginning, pretend in
-			 * page header there is a record ending where actual data will
-			 * start.
-			 */
-			xlogPageHdr->xlp_rem_len = offs - lastPageSize;
-			xlogPageHdr->xlp_info = (xlogPageHdr->xlp_rem_len > 0) ? XLP_FIRST_IS_CONTRECORD : 0;
-
-			/* Populate the long header correctly, if  */
-			if ((pageBeginPtr & (wal_segment_size - 1)) == 0)
+			memcpy(page, xlogreader->readBuf, offs);
+			/* if the buffer was zeroed, manually construct the page header */
+			if (xlogPageHdr->xlp_magic != XLOG_PAGE_MAGIC)
 			{
-				XLogLongPageHeader longHdr = (XLogLongPageHeader) xlogPageHdr;
-				xlogPageHdr->xlp_info |= XLP_LONG_HEADER;
-				longHdr->xlp_seg_size = wal_segment_size;
-				longHdr->xlp_sysid = GetSystemIdentifier();
-				longHdr->xlp_xlog_blcksz = XLOG_BLCKSZ;
-			}
+				xlogPageHdr->xlp_pageaddr = pageBeginPtr;
+				xlogPageHdr->xlp_magic = XLOG_PAGE_MAGIC;
+				xlogPageHdr->xlp_tli = recoveryTargetTLI;
+				/*
+				 * If we start writing with offset from page beginning, pretend in
+				 * page header there is a record ending where actual data will
+				 * start.
+				 */
+				xlogPageHdr->xlp_rem_len = offs - lastPageSize;
+				xlogPageHdr->xlp_info = (xlogPageHdr->xlp_rem_len > 0) ? XLP_FIRST_IS_CONTRECORD : 0;
 
-			readOff = XLogSegmentOffset(pageBeginPtr, wal_segment_size);
+				/* Populate the long header, if needed */
+				if ((pageBeginPtr & (wal_segment_size - 1)) == 0)
+				{
+					XLogLongPageHeader longHdr = (XLogLongPageHeader) xlogPageHdr;
+					xlogPageHdr->xlp_info |= XLP_LONG_HEADER;
+					longHdr->xlp_seg_size = wal_segment_size;
+					longHdr->xlp_sysid = GetSystemIdentifier();
+					longHdr->xlp_xlog_blcksz = XLOG_BLCKSZ;
+				}
 
+				readOff = XLogSegmentOffset(pageBeginPtr, wal_segment_size);
+			}
 			result->lastPageBeginPtr = pageBeginPtr;
 			result->lastPage = page;
 			elog(LOG, "Continue writing WAL at %X/%X", LSN_FORMAT_ARGS(xlogreader->EndRecPtr));