From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 4 Dec 2010 03:43:01 +0000 (-0500)
Subject: Put back gistgettuple's check for backwards scan request.
X-Git-Tag: REL9_1_ALPHA3~94
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=04910a3ad5cd2901558da2a4fad9a2e2819348aa;p=postgresql

Put back gistgettuple's check for backwards scan request.

On reflection it's a bad idea for the KNNGIST patch to have removed that.
We don't want it silently returning incorrect answers.
---

diff --git a/src/backend/access/gist/gistget.c b/src/backend/access/gist/gistget.c
index f0418a08af..afff55c788 100644
--- a/src/backend/access/gist/gistget.c
+++ b/src/backend/access/gist/gistget.c
@@ -459,8 +459,12 @@ Datum
 gistgettuple(PG_FUNCTION_ARGS)
 {
 	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
+	ScanDirection dir = (ScanDirection) PG_GETARG_INT32(1);
 	GISTScanOpaque so = (GISTScanOpaque) scan->opaque;
 
+	if (dir != ForwardScanDirection)
+		elog(ERROR, "GiST only supports forward scan direction");
+
 	if (!so->qual_ok)
 		PG_RETURN_BOOL(false);