From 49e7c7672d6d065435f7058df90b082cb552c7dd Mon Sep 17 00:00:00 2001
From: Lucas Bremgartner <lucas@bremis.ch>
Date: Fri, 13 Sep 2019 19:46:50 +0000
Subject: [PATCH] encoding/json: make Number with the ,string option marshal
 with quotes
MIME-Version: 1.0
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Content-Transfer-Encoding: 8bit

Add quotes when marshaling a json.Number with the string option
set via a struct tag. This ensures that the resulting json
can be unmarshaled into the source struct without error.

Fixes #34268

Change-Id: Ide167d9dec77019554870b5957b37dc258119d81
GitHub-Last-Rev: dde81b71208be01c253bb87dbb6f81ac6e0785be
GitHub-Pull-Request: golang/go#34269
Reviewed-on: https://go-review.googlesource.com/c/go/+/195043
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
---
 src/encoding/json/encode.go      | 6 ++++++
 src/encoding/json/encode_test.go | 5 ++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/encoding/json/encode.go b/src/encoding/json/encode.go
index e5dd1b7799..b4fba476c8 100644
--- a/src/encoding/json/encode.go
+++ b/src/encoding/json/encode.go
@@ -600,7 +600,13 @@ func stringEncoder(e *encodeState, v reflect.Value, opts encOpts) {
 		if !isValidNumber(numStr) {
 			e.error(fmt.Errorf("json: invalid number literal %q", numStr))
 		}
+		if opts.quoted {
+			e.WriteByte('"')
+		}
 		e.WriteString(numStr)
+		if opts.quoted {
+			e.WriteByte('"')
+		}
 		return
 	}
 	if opts.quoted {
diff --git a/src/encoding/json/encode_test.go b/src/encoding/json/encode_test.go
index 18a92bae7c..8d3503b1ba 100644
--- a/src/encoding/json/encode_test.go
+++ b/src/encoding/json/encode_test.go
@@ -76,13 +76,15 @@ type StringTag struct {
 	IntStr     int64   `json:",string"`
 	UintptrStr uintptr `json:",string"`
 	StrStr     string  `json:",string"`
+	NumberStr  Number  `json:",string"`
 }
 
 var stringTagExpected = `{
  "BoolStr": "true",
  "IntStr": "42",
  "UintptrStr": "44",
- "StrStr": "\"xzbit\""
+ "StrStr": "\"xzbit\"",
+ "NumberStr": "46"
 }`
 
 func TestStringTag(t *testing.T) {
@@ -91,6 +93,7 @@ func TestStringTag(t *testing.T) {
 	s.IntStr = 42
 	s.UintptrStr = 44
 	s.StrStr = "xzbit"
+	s.NumberStr = "46"
 	got, err := MarshalIndent(&s, "", " ")
 	if err != nil {
 		t.Fatal(err)
-- 
2.50.0