Make XLogRecGetBlockTag() throw error if there's no such block.

All but a few existing callers assume without checking that this
function succeeds.  While it probably will, that's a poor excuse for
not checking.  Let's make it return void and instead throw an error
if it doesn't find the block reference.  Callers that actually need
to handle the no-such-block case must now use the underlying function
XLogRecGetBlockTagExtended.

In addition to being a bit less error-prone, this should also serve
to suppress some Coverity complaints about XLogRecGetBlockRefInfo.

While at it, clean up some inconsistency about use of the
XLogRecHasBlockRef macro: make XLogRecGetBlockTagExtended use
that instead of open-coding the same condition, and avoid calling
XLogRecHasBlockRef twice in relevant code paths.  (That is,
calling XLogRecHasBlockRef followed by XLogRecGetBlockTag is now
deprecated: use XLogRecGetBlockTagExtended instead.)

Patch HEAD only; this doesn't seem to have enough value to consider
a back-branch API break.

Discussion: https://postgr.es/m/425039.1649701221@sss.pgh.pa.us

1 files changed, 1 insertions, 1 deletions

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index a03122df8d6..ba11bcd99e9 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -9363,7 +9363,7 @@ heap_xlog_update(XLogReaderState *record, bool hot_update)
 	oldtup.t_len = 0;
 
 	XLogRecGetBlockTag(record, 0, &rnode, NULL, &newblk);
-	if (XLogRecGetBlockTag(record, 1, NULL, NULL, &oldblk))
+	if (XLogRecGetBlockTagExtended(record, 1, NULL, NULL, &oldblk, NULL))
 	{
 		/* HOT updates are never done across pages */
 		Assert(!hot_update);