From 0f1bda20b06513437fbbe380d444cf1404ce6a2c Mon Sep 17 00:00:00 2001
From: Jack Christensen <jack@jackchristensen.com>
Date: Thu, 11 Mar 2021 19:48:47 -0600
Subject: [PATCH] Fix numeric NaN support

fixes #93
---
 numeric.go      | 14 +++++---------
 numeric_test.go |  5 ++++-
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/numeric.go b/numeric.go
index f2b04006..4d966d5e 100644
--- a/numeric.go
+++ b/numeric.go
@@ -16,8 +16,8 @@ import (
 const nbase = 10000
 
 const (
-	pgNumericNaN     = 0x000000000c000000
-	pgNumericNaNSign = 0x0c00
+	pgNumericNaN     = 0x00000000c0000000
+	pgNumericNaNSign = 0xc000
 )
 
 var big0 *big.Int = big.NewInt(0)
@@ -406,7 +406,7 @@ func (dst *Numeric) DecodeText(ci *ConnInfo, src []byte) error {
 		return nil
 	}
 
-	if string(src) == "'NaN'" { // includes single quotes, see EncodeText for details.
+	if string(src) == "NaN" {
 		*dst = Numeric{Status: Present, NaN: true}
 		return nil
 	}
@@ -456,7 +456,7 @@ func (dst *Numeric) DecodeBinary(ci *ConnInfo, src []byte) error {
 	rp += 2
 	weight := int16(binary.BigEndian.Uint16(src[rp:]))
 	rp += 2
-	sign := int16(binary.BigEndian.Uint16(src[rp:]))
+	sign := uint16(binary.BigEndian.Uint16(src[rp:]))
 	rp += 2
 	dscale := int16(binary.BigEndian.Uint16(src[rp:]))
 	rp += 2
@@ -573,11 +573,7 @@ func (src Numeric) EncodeText(ci *ConnInfo, buf []byte) ([]byte, error) {
 	}
 
 	if src.NaN {
-		// encode as 'NaN' including single quotes,
-		// "When writing this value [NaN] as a constant in an SQL command,
-		// you must put quotes around it, for example UPDATE table SET x = 'NaN'"
-		// https://www.postgresql.org/docs/9.3/datatype-numeric.html
-		buf = append(buf, "'NaN'"...)
+		buf = append(buf, "NaN"...)
 		return buf, nil
 	}
 
diff --git a/numeric_test.go b/numeric_test.go
index 675eddc4..81595cb3 100644
--- a/numeric_test.go
+++ b/numeric_test.go
@@ -15,7 +15,8 @@ import (
 func numericEqual(left, right *pgtype.Numeric) bool {
 	return left.Status == right.Status &&
 		left.Exp == right.Exp &&
-		((left.Int == nil && right.Int == nil) || (left.Int != nil && right.Int != nil && left.Int.Cmp(right.Int) == 0))
+		((left.Int == nil && right.Int == nil) || (left.Int != nil && right.Int != nil && left.Int.Cmp(right.Int) == 0)) &&
+		left.NaN == right.NaN
 }
 
 // For test purposes only.
@@ -117,6 +118,8 @@ func TestNumericNormalize(t *testing.T) {
 
 func TestNumericTranscode(t *testing.T) {
 	testutil.TestSuccessfulTranscodeEqFunc(t, "numeric", []interface{}{
+		&pgtype.Numeric{NaN: true, Status: pgtype.Present},
+
 		&pgtype.Numeric{Int: big.NewInt(0), Exp: 0, Status: pgtype.Present},
 		&pgtype.Numeric{Int: big.NewInt(1), Exp: 0, Status: pgtype.Present},
 		&pgtype.Numeric{Int: big.NewInt(-1), Exp: 0, Status: pgtype.Present},