Fix typo in comment

Once upon a time, WAL pointers could be NULL, but no longer.  We talk about
"valid" now.

Reported-by: Amit Langote
Discussion: https://postgr.es/m/33e9617d-27f1-eee8-3311-e27af98eaf2b@lab.ntt.co.jp

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index e60433ba0baf89a6e7b1399f04596862dd8f548b..0a6314a64267a232d201b195c46944bb13e0b5c2 100644 (file)
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -4131,7 +4131,7 @@ CleanupBackupHistory(void)
 /*
  * Attempt to read an XLOG record.
  *
- * If RecPtr is not NULL, try to read a record at that position.  Otherwise
+ * If RecPtr is valid, try to read a record at that position.  Otherwise
  * try to read a record just after the last one previously read.
  *
  * If no valid record is available, returns NULL, or fails if emode is PANIC.