From 58eeefeef48619d8f3f15954c9f923a56515dd51 Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Mon, 25 Mar 2024 15:40:15 -0700
Subject: [PATCH] Handle nulls

---
 src/hnswscan.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/hnswscan.c b/src/hnswscan.c
index eaf0519..ce0c2f3 100644
--- a/src/hnswscan.c
+++ b/src/hnswscan.c
@@ -6,6 +6,7 @@
 #include "storage/bufmgr.h"
 #include "storage/lmgr.h"
 #include "utils/memutils.h"
+#include "utils/varbit.h"
 
 /*
  * Algorithm 5 from paper
@@ -73,7 +74,22 @@ GetScanValue(IndexScanDesc scan)
 	Datum		value;
 
 	if (scan->orderByData->sk_flags & SK_ISNULL)
-		value = PointerGetDatum(InitVector(GetDimensions(scan->indexRelation)));
+	{
+		Oid			typid = TupleDescAttr(scan->indexRelation->rd_att, 0)->atttypid;
+		int			dimensions = GetDimensions(scan->indexRelation);
+
+		if (typid == BITOID || typid == VARBITOID)
+		{
+			int			len = VARBITTOTALLEN(dimensions);
+			VarBit	   *v = (VarBit *) palloc0(len);
+
+			SET_VARSIZE(v, len);
+			VARBITLEN(v) = dimensions;
+			value = PointerGetDatum(v);
+		}
+		else
+			value = PointerGetDatum(InitVector(dimensions));
+	}
 	else
 	{
 		value = scan->orderByData->sk_argument;