Revert no-op changes to BufferGetPage()

The reverted changes were intended to force a choice of whether any
newly-added BufferGetPage() calls needed to be accompanied by a
test of the snapshot age, to support the "snapshot too old"
feature.  Such an accompanying test is needed in about 7% of the
cases, where the page is being used as part of a scan rather than
positioning for other purposes (such as DML or vacuuming).  The
additional effort required for back-patching, and the doubt whether
the intended benefit would really be there, have indicated it is
best just to rely on developers to do the right thing based on
comments and existing usage, as we do with many other conventions.

This change should have little or no effect on generated executable
code.

Motivated by the back-patching pain of Tom Lane and Robert Haas

3 files changed, 9 insertions, 11 deletions

diff --git a/contrib/pgstattuple/pgstatapprox.c b/contrib/pgstattuple/pgstatapprox.c
index b7734fac88..a49ff543d2 100644
--- a/contrib/pgstattuple/pgstatapprox.c
+++ b/contrib/pgstattuple/pgstatapprox.c
@@ -100,7 +100,7 @@ statapprox_heap(Relation rel, output_type *stat)
 
 		LockBuffer(buf, BUFFER_LOCK_SHARE);
 
-		page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		page = BufferGetPage(buf);
 
 		/*
 		 * It's not safe to call PageGetHeapFreeSpace() on new pages, so we
diff --git a/contrib/pgstattuple/pgstatindex.c b/contrib/pgstattuple/pgstatindex.c
index 4596632c09..9f1377c4cd 100644
--- a/contrib/pgstattuple/pgstatindex.c
+++ b/contrib/pgstattuple/pgstatindex.c
@@ -173,7 +173,7 @@ pgstatindex_impl(Relation rel, FunctionCallInfo fcinfo)
 	 */
 	{
 		Buffer		buffer = ReadBufferExtended(rel, MAIN_FORKNUM, 0, RBM_NORMAL, bstrategy);
-		Page		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		Page		page = BufferGetPage(buffer);
 		BTMetaPageData *metad = BTPageGetMeta(page);
 
 		indexStat.version = metad->btm_version;
@@ -211,7 +211,7 @@ pgstatindex_impl(Relation rel, FunctionCallInfo fcinfo)
 		buffer = ReadBufferExtended(rel, MAIN_FORKNUM, blkno, RBM_NORMAL, bstrategy);
 		LockBuffer(buffer, BUFFER_LOCK_SHARE);
 
-		page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+		page = BufferGetPage(buffer);
 		opaque = (BTPageOpaque) PageGetSpecialPointer(page);
 
 		/* Determine page type, and update totals */
@@ -399,7 +399,7 @@ pgstatginindex(PG_FUNCTION_ARGS)
 	 */
 	buffer = ReadBuffer(rel, GIN_METAPAGE_BLKNO);
 	LockBuffer(buffer, GIN_SHARE);
-	page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = BufferGetPage(buffer);
 	metadata = GinPageGetMeta(page);
 
 	stats.version = metadata->ginVersion;
diff --git a/contrib/pgstattuple/pgstattuple.c b/contrib/pgstattuple/pgstattuple.c
index 46655ac01c..c1122b496a 100644
--- a/contrib/pgstattuple/pgstattuple.c
+++ b/contrib/pgstattuple/pgstattuple.c
@@ -320,8 +320,7 @@ pgstat_heap(Relation rel, FunctionCallInfo fcinfo)
 			buffer = ReadBufferExtended(rel, MAIN_FORKNUM, block,
 										RBM_NORMAL, scan->rs_strategy);
 			LockBuffer(buffer, BUFFER_LOCK_SHARE);
-			stat.free_space += PageGetHeapFreeSpace
-				(BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST));
+			stat.free_space += PageGetHeapFreeSpace((Page) BufferGetPage(buffer));
 			UnlockReleaseBuffer(buffer);
 			block++;
 		}
@@ -334,8 +333,7 @@ pgstat_heap(Relation rel, FunctionCallInfo fcinfo)
 		buffer = ReadBufferExtended(rel, MAIN_FORKNUM, block,
 									RBM_NORMAL, scan->rs_strategy);
 		LockBuffer(buffer, BUFFER_LOCK_SHARE);
-		stat.free_space += PageGetHeapFreeSpace
-			(BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST));
+		stat.free_space += PageGetHeapFreeSpace((Page) BufferGetPage(buffer));
 		UnlockReleaseBuffer(buffer);
 		block++;
 	}
@@ -360,7 +358,7 @@ pgstat_btree_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno,
 
 	buf = ReadBufferExtended(rel, MAIN_FORKNUM, blkno, RBM_NORMAL, bstrategy);
 	LockBuffer(buf, BT_READ);
-	page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = BufferGetPage(buf);
 
 	/* Page is valid, see what to do with it */
 	if (PageIsNew(page))
@@ -404,7 +402,7 @@ pgstat_hash_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno,
 
 	_hash_getlock(rel, blkno, HASH_SHARE);
 	buf = _hash_getbuf_with_strategy(rel, blkno, HASH_READ, 0, bstrategy);
-	page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = BufferGetPage(buf);
 
 	if (PageGetSpecialSize(page) == MAXALIGN(sizeof(HashPageOpaqueData)))
 	{
@@ -449,7 +447,7 @@ pgstat_gist_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno,
 	buf = ReadBufferExtended(rel, MAIN_FORKNUM, blkno, RBM_NORMAL, bstrategy);
 	LockBuffer(buf, GIST_SHARE);
 	gistcheckpage(rel, buf);
-	page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
+	page = BufferGetPage(buf);
 
 	if (GistPageIsLeaf(page))
 	{