From: David Symonds <dsymonds@golang.org>
Date: Tue, 1 May 2012 01:37:44 +0000 (+1000)
Subject: encoding/json: don't match field name if a JSON struct tag is present.
X-Git-Tag: go1.1rc2~3275
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=c3c8e35af25d99f5cfab70157e26a13b93a77e7f;p=gostls13.git

encoding/json: don't match field name if a JSON struct tag is present.

Fixes #3566.

R=rsc
CC=golang-dev
https://golang.org/cl/6139048
---

diff --git a/src/pkg/encoding/json/decode.go b/src/pkg/encoding/json/decode.go
index 110c6fd623..701cba9bd0 100644
--- a/src/pkg/encoding/json/decode.go
+++ b/src/pkg/encoding/json/decode.go
@@ -504,10 +504,15 @@ func (d *decodeState) object(v reflect.Value) {
 				}
 				// First, tag match
 				tagName, _ := parseTag(tag)
-				if tagName == key {
-					f = sf
-					ok = true
-					break // no better match possible
+				if tagName != "" {
+					if tagName == key {
+						f = sf
+						ok = true
+						break // no better match possible
+					}
+					// There was a tag, but it didn't match.
+					// Ignore field names.
+					continue
 				}
 				// Second, exact field name match
 				if sf.Name == key {
diff --git a/src/pkg/encoding/json/decode_test.go b/src/pkg/encoding/json/decode_test.go
index d758758d97..78768c8ba1 100644
--- a/src/pkg/encoding/json/decode_test.go
+++ b/src/pkg/encoding/json/decode_test.go
@@ -18,6 +18,10 @@ type T struct {
 	Z int `json:"-"`
 }
 
+type U struct {
+	Alphabet string `json:"alpha"`
+}
+
 type tx struct {
 	x int
 }
@@ -72,6 +76,10 @@ var unmarshalTests = []unmarshalTest{
 	// Z has a "-" tag.
 	{`{"Y": 1, "Z": 2}`, new(T), T{Y: 1}, nil},
 
+	{`{"alpha": "abc", "alphabet": "xyz"}`, new(U), U{Alphabet: "abc"}, nil},
+	{`{"alpha": "abc"}`, new(U), U{Alphabet: "abc"}, nil},
+	{`{"alphabet": "xyz"}`, new(U), U{}, nil},
+
 	// syntax errors
 	{`{"X": "foo", "Y"}`, nil, nil, &SyntaxError{"invalid character '}' after object key", 17}},
 	{`[1, 2, 3+]`, nil, nil, &SyntaxError{"invalid character '+' after array element", 9}},