3 files changed, 24 insertions, 10 deletions
diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index b3e37003ac5..cf5db23cb86 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -37,6 +37,8 @@
 #include "miscadmin.h"
 #include "pgstat.h"
 #include "utils/memutils.h"
+#else
+#include "common/logging.h"
 #endif
 
 static void report_invalid_record(XLogReaderState *state, const char *fmt,...)
@@ -1918,14 +1920,25 @@ err:
 
 /*
  * Returns information about the block that a block reference refers to.
- * See XLogRecGetBlockTagExtended().
+ *
+ * This is like XLogRecGetBlockTagExtended, except that the block reference
+ * must exist and there's no access to prefetch_buffer.
  */
-bool
+void
 XLogRecGetBlockTag(XLogReaderState *record, uint8 block_id,
 				   RelFileNode *rnode, ForkNumber *forknum, BlockNumber *blknum)
 {
-	return XLogRecGetBlockTagExtended(record, block_id, rnode, forknum, blknum,
-									  NULL);
+	if (!XLogRecGetBlockTagExtended(record, block_id, rnode, forknum, blknum,
+									NULL))
+	{
+#ifndef FRONTEND
+		elog(ERROR, "failed to locate backup block with ID %d in WAL record",
+			 block_id);
+#else
+		pg_fatal("failed to locate backup block with ID %d in WAL record",
+				 block_id);
+#endif
+	}
 }
 
 /*
@@ -1944,8 +1957,7 @@ XLogRecGetBlockTagExtended(XLogReaderState *record, uint8 block_id,
 {
 	DecodedBkpBlock *bkpb;
 
-	if (block_id > record->record->max_block_id ||
-		!record->record->blocks[block_id].in_use)
+	if (!XLogRecHasBlockRef(record, block_id))
 		return false;
 
 	bkpb = &record->record->blocks[block_id];
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index 4ee29182ac8..26be94b3f19 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -2172,10 +2172,10 @@ xlog_block_info(StringInfo buf, XLogReaderState *record)
 		ForkNumber	forknum;
 		BlockNumber blk;
 
-		if (!XLogRecHasBlockRef(record, block_id))
+		if (!XLogRecGetBlockTagExtended(record, block_id,
+										&rnode, &forknum, &blk, NULL))
 			continue;
 
-		XLogRecGetBlockTag(record, block_id, &rnode, &forknum, &blk);
 		if (forknum != MAIN_FORKNUM)
 			appendStringInfo(buf, "; blkref #%d: rel %u/%u/%u, fork %u, blk %u",
 							 block_id,
@@ -2303,7 +2303,8 @@ verifyBackupPageConsistency(XLogReaderState *record)
 		Buffer		buf;
 		Page		page;
 
-		if (!XLogRecGetBlockTag(record, block_id, &rnode, &forknum, &blkno))
+		if (!XLogRecGetBlockTagExtended(record, block_id,
+										&rnode, &forknum, &blkno, NULL))
 		{
 			/*
 			 * WAL record doesn't contain a block reference with the given id.
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index b5d34c61e66..425702641a6 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -369,7 +369,8 @@ XLogReadBufferForRedoExtended(XLogReaderState *record,
 									&prefetch_buffer))
 	{
 		/* Caller specified a bogus block_id */
-		elog(PANIC, "failed to locate backup block with ID %d", block_id);
+		elog(PANIC, "failed to locate backup block with ID %d in WAL record",
+			 block_id);
 	}
 
 	/*