From ebeac156c0bf2a038df57a29128e636d346f3d5d Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Wed, 26 May 2021 13:40:38 -0700
Subject: [PATCH] Require unused to be 0

---
 src/vector.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/vector.c b/src/vector.c
index 3d95785..c0669ee 100644
--- a/src/vector.c
+++ b/src/vector.c
@@ -244,14 +244,20 @@ vector_recv(PG_FUNCTION_ARGS)
 	int32		typmod = PG_GETARG_INT32(2);
 	Vector	   *result;
 	int16		dim;
+	int16		unused;
 	int			i;
 
 	dim = pq_getmsgint(buf, sizeof(int16));
-	pq_getmsgint(buf, sizeof(int16));	/* unused */
+	unused = pq_getmsgint(buf, sizeof(int16));
 
 	CheckDim(dim);
 	CheckExpectedDim(typmod, dim);
 
+	if (unused != 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_EXCEPTION),
+				 errmsg("expected unused to be 0, not %d", unused)));
+
 	result = InitVector(dim);
 	for (i = 0; i < dim; i++)
 		result->x[i] = pq_getmsgfloat4(buf);