From: cuiweixie <cuiweixie@gmail.com>
Date: Sat, 12 Feb 2022 15:19:18 +0000 (+0000)
Subject: math/big: produce valid JSON in Int.MarshalJSON when nil
X-Git-Tag: go1.19beta1~1202
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=9f1239b90a7a48c5dc68a7eee08d8e1fba56db80;p=gostls13.git

math/big: produce valid JSON in Int.MarshalJSON when nil

Fixes #50940.

Change-Id: Ie2a0c4505ca9d7e448017d9d00a020a6b3996be3
GitHub-Last-Rev: afd8c6b5598f43de25831c700b8d76cd97571426
GitHub-Pull-Request: golang/go#50941
Reviewed-on: https://go-review.googlesource.com/c/go/+/381963
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Trust: Daniel Martí <mvdan@mvdan.cc>
---

diff --git a/src/math/big/intmarsh.go b/src/math/big/intmarsh.go
index c1422e2710..ce429ffc11 100644
--- a/src/math/big/intmarsh.go
+++ b/src/math/big/intmarsh.go
@@ -67,7 +67,10 @@ func (z *Int) UnmarshalText(text []byte) error {
 
 // MarshalJSON implements the json.Marshaler interface.
 func (x *Int) MarshalJSON() ([]byte, error) {
-	return x.MarshalText()
+	if x == nil {
+		return []byte("null"), nil
+	}
+	return x.abs.itoa(x.neg, 10), nil
 }
 
 // UnmarshalJSON implements the json.Unmarshaler interface.
diff --git a/src/math/big/intmarsh_test.go b/src/math/big/intmarsh_test.go
index f82956ceaf..936669b380 100644
--- a/src/math/big/intmarsh_test.go
+++ b/src/math/big/intmarsh_test.go
@@ -97,6 +97,20 @@ func TestIntJSONEncoding(t *testing.T) {
 	}
 }
 
+
+func TestIntJSONEncodingNil(t *testing.T) {
+	var x *Int
+	b, err := x.MarshalJSON()
+	if err != nil {
+		t.Fatalf("marshaling of nil failed: %s", err)
+	}
+	got := string(b)
+	want := "null"
+	if got != want {
+		t.Fatalf("marshaling of nil failed: got %s want %s", got, want)
+	}
+}
+
 func TestIntXMLEncoding(t *testing.T) {
 	for _, test := range encodingTests {
 		for _, sign := range []string{"", "+", "-"} {