diff --git a/src/backend/storage/file/buffile.c b/src/backend/storage/file/buffile.c
index ccaed0efa064f92f105f13b7c5fb1d5bbbafd1dd..4f3a8a311bf26ccf4ac5ca5c340156d092b23efc 100644
--- a/src/backend/storage/file/buffile.c
+++ b/src/backend/storage/file/buffile.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/file/buffile.c,v 1.25 2007/01/05 22:19:37 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/file/buffile.c,v 1.26 2007/06/01 23:43:11 tgl Exp $
  *
  * NOTES:
  *
@@ -289,7 +289,7 @@ BufFileDumpBuffer(BufFile *file)
 				return;			/* seek failed, give up */
 			file->offsets[file->curFile] = file->curOffset;
 		}
-		bytestowrite = FileWrite(thisfile, file->buffer, bytestowrite);
+		bytestowrite = FileWrite(thisfile, file->buffer + wpos, bytestowrite);
 		if (bytestowrite <= 0)
 			return;				/* failed to write */
 		file->offsets[file->curFile] += bytestowrite;