Fix page-level checksum calculation in checksum_impl.h

michaelpq · michaelpq · commit addd034ae179 · 2020-03-06T08:15:29.000+09:00
Issue introduced by me, as of 0065174. Reported-by: David Steele Discussion: https://postgr.es/m/1cf30561-7dad-dc6e-9fc3-5c456948cfeb@pgmasters.net
diff --git a/src/include/storage/checksum_impl.h b/src/include/storage/checksum_impl.h
@@ -211,5 +211,5 @@ pg_checksum_page(char *page, BlockNumber blkno)
 	 * Reduce to a uint16 (to fit in the pd_checksum field) with an offset of
 	 * one. That avoids checksums of zero, which seems like a good idea.
 	 */
-	return (uint16) ((checksum % 65536) + 1);
+	return (uint16) ((checksum % 65535) + 1);
 }

Original file line number	Diff line number	Diff line change
`@@ -211,5 +211,5 @@ pg_checksum_page(char *page, BlockNumber blkno)`
`211`	`211`	`* Reduce to a uint16 (to fit in the pd_checksum field) with an offset of`
`212`	`212`	`* one. That avoids checksums of zero, which seems like a good idea.`
`213`	`213`	`*/`
`214`		`- return (uint16) ((checksum % 65536) + 1);`
	`214`	`+ return (uint16) ((checksum % 65535) + 1);`
`215`	`215`	`}`