diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
new file mode 100644
index 3a86f34..764a579
*** a/src/backend/access/transam/xlogreader.c
--- b/src/backend/access/transam/xlogreader.c
*************** XLogReadRecord(XLogReaderState *state, X
*** 345,351 ****
  		goto err;
  	}
  
! 	len = XLOG_BLCKSZ - RecPtr % XLOG_BLCKSZ;
  	if (total_len > len)
  	{
  		/* Need to reassemble record */
--- 345,365 ----
  		goto err;
  	}
  
! 	/* Bytes of the current record residing on the current page. */
! 	len = Min(XLOG_BLCKSZ - targetRecOff, total_len);
! 
! 	/*
! 	 * Nothing beyond the record header is guaranteed to be in state->readBuf
! 	 * so far.
! 	 */
! 	if (readOff < targetRecOff + len)
! 	{
! 		readOff = ReadPageInternal(state, targetPagePtr, targetRecOff + len);
! 
! 		if (readOff < 0)
! 			goto err;
! 	}
! 
  	if (total_len > len)
  	{
  		/* Need to reassemble record */
*************** XLogReadRecord(XLogReaderState *state, X
*** 354,362 ****
  		char	   *buffer;
  		uint32		gotlen;
  
  		/* Copy the first fragment of the record from the first page. */
! 		memcpy(state->readRecordBuf,
! 			   state->readBuf + RecPtr % XLOG_BLCKSZ, len);
  		buffer = state->readRecordBuf + len;
  		gotlen = len;
  
--- 368,378 ----
  		char	   *buffer;
  		uint32		gotlen;
  
+ 		Assert(readOff == targetRecOff + len);
+ 		Assert(readOff == XLOG_BLCKSZ);
+ 
  		/* Copy the first fragment of the record from the first page. */
! 		memcpy(state->readRecordBuf, state->readBuf + targetRecOff, len);
  		buffer = state->readRecordBuf + len;
  		gotlen = len;
  
*************** XLogReadRecord(XLogReaderState *state, X
*** 445,464 ****
  	}
  	else
  	{
! 		/* Wait for the record data to become available */
! 		readOff = ReadPageInternal(state, targetPagePtr,
! 								   Min(targetRecOff + total_len, XLOG_BLCKSZ));
! 		if (readOff < 0)
! 			goto err;
  
  		/* Record does not cross a page boundary */
  		if (!ValidXLogRecord(state, record, RecPtr))
  			goto err;
  
! 		state->EndRecPtr = RecPtr + MAXALIGN(total_len);
  
  		state->ReadRecPtr = RecPtr;
! 		memcpy(state->readRecordBuf, record, total_len);
  	}
  
  	/*
--- 461,480 ----
  	}
  	else
  	{
! 		/*
! 		 * The whole record is on the current page and should have been
! 		 * fetched into readBuf.
! 		 */
! 		Assert(readOff >= targetRecOff + len);
  
  		/* Record does not cross a page boundary */
  		if (!ValidXLogRecord(state, record, RecPtr))
  			goto err;
  
! 		state->EndRecPtr = RecPtr + MAXALIGN(len);
  
  		state->ReadRecPtr = RecPtr;
! 		memcpy(state->readRecordBuf, record, len);
  	}
  
  	/*