Test-left-jumps-2.patch

diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index 3f52b8f4dc..cad4a2a46e 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -1187,6 +1187,8 @@ gistinserttuple(GISTInsertState *state, GISTInsertStack *stack,
 							InvalidBuffer, InvalidBuffer, false, false);
 }
 
+static bool HACK = false;
+
 /* ----------------
  * An extended workhorse version of gistinserttuple(). This version allows
  * inserting multiple tuples, or replacing a single tuple with multiple tuples.
@@ -1230,6 +1232,14 @@ gistinserttuples(GISTInsertState *state, GISTInsertStack *stack,
 	CheckForSerializableConflictIn(state->r, NULL, stack->buffer);
 
 	/* Insert the tuple(s) to the page, splitting the page if necessary */
+	if (BufferIsValid(leftchild) && HACK)
+	{
+		/* skip actually inserting */
+		splitinfo = NULL;
+		is_split = false;
+	}
+	else
+	{
 	is_split = gistplacetopage(state->r, state->freespace, giststate,
 							   stack->buffer,
 							   tuples, ntup,
@@ -1238,6 +1248,7 @@ gistinserttuples(GISTInsertState *state, GISTInsertStack *stack,
 							   &splitinfo,
 							   true,
 							   state->heapRel);
+	}
 
 	/*
 	 * Before recursing up in case the page was split, release locks on the
@@ -1256,7 +1267,12 @@ gistinserttuples(GISTInsertState *state, GISTInsertStack *stack,
 	 * didn't have to split, release it ourselves.
 	 */
 	if (splitinfo)
+	{
+		if (random() % 2 == 0)
+			HACK = true;
 		gistfinishsplit(state, stack, giststate, splitinfo, unlockbuf);
+		HACK = false;
+	}
 	else if (unlockbuf)
 		LockBuffer(stack->buffer, GIST_UNLOCK);
 
diff --git a/src/backend/access/gist/gistbuild.c b/src/backend/access/gist/gistbuild.c
index bd142a3560..fdfc54b009 100644
--- a/src/backend/access/gist/gistbuild.c
+++ b/src/backend/access/gist/gistbuild.c
@@ -201,6 +201,9 @@ gistbuild(Relation heap, Relation index, IndexInfo *indexInfo)
 	buildstate.indtuples = 0;
 	buildstate.indtuplesSize = 0;
 
+	for (int i = 0; i < 100; i++)
+		ReleaseBuffer(ReadBuffer(index, P_NEW));
+
 	/*
 	 * Do the heap scan.
 	 */
diff --git a/src/backend/access/gist/gistvacuum.c b/src/backend/access/gist/gistvacuum.c
index 1cbcb038f7..c306621e1e 100644
--- a/src/backend/access/gist/gistvacuum.c
+++ b/src/backend/access/gist/gistvacuum.c
@@ -254,6 +254,11 @@ restart:
 			(opaque->rightlink != InvalidBlockNumber) &&
 			(opaque->rightlink < orig_blkno))
 		{
+			if (GistFollowRight(page))
+				elog(LOG, "RESCAN %u->%u TRIGGERED BY FollowRight", blkno, opaque->rightlink);
+			if (vstate->startNSN < GistPageGetNSN(page))
+				elog(LOG,"RESCAN %u->%u TRIGGERED BY NSN", blkno, opaque->rightlink);
+
 			recurse_to = opaque->rightlink;
 		}