encoding/json: encode \t as \t instead of \u0009

Shorter and easier to read form for a common character.

LGTM=bradfitz
R=adg, bradfitz
CC=golang-codereviews, zimmski
https://golang.org/cl/162340043

diff --git a/src/encoding/json/encode.go b/src/encoding/json/encode.go
index 9b7b9d5fd18b860c8a938c7556703f3620a1eb45..fca2a0980b2a36a30e8d80f79e1261088acea4c8 100644 (file)
--- a/src/encoding/json/encode.go
+++ b/src/encoding/json/encode.go
@@ -805,6 +805,9 @@ func (e *encodeState) string(s string) (int, error) {
                        case '\r':
                                e.WriteByte('\\')
                                e.WriteByte('r')
+                       case '\t':
+                               e.WriteByte('\\')
+                               e.WriteByte('t')
                        default:
                                // This encodes bytes < 0x20 except for \n and \r,
                                // as well as <, > and &. The latter are escaped because they
@@ -878,9 +881,12 @@ func (e *encodeState) stringBytes(s []byte) (int, error) {
                        case '\r':
                                e.WriteByte('\\')
                                e.WriteByte('r')
+                       case '\t':
+                               e.WriteByte('\\')
+                               e.WriteByte('t')
                        default:
                                // This encodes bytes < 0x20 except for \n and \r,
-                               // as well as < and >. The latter are escaped because they
+                               // as well as <, >, and &. The latter are escaped because they
                                // can lead to security holes when user-controlled strings
                                // are rendered into JSON and served to some browsers.
                                e.WriteString(`\u00`)

diff --git a/src/encoding/json/encode_test.go b/src/encoding/json/encode_test.go
index eb84cbae14ca79580ed9a7dfac80ab21e9ea3d61..7abfa85db7bc243c6c057a476297dce62cc9c5f7 100644 (file)
--- a/src/encoding/json/encode_test.go
+++ b/src/encoding/json/encode_test.go
@@ -478,3 +478,55 @@ func TestEncodePointerString(t *testing.T) {
                t.Fatalf("*N = %d; want 42", *back.N)
        }
 }
+
+var encodeStringTests = []struct {
+       in  string
+       out string
+}{
+       {"\x00", `"\u0000"`},
+       {"\x01", `"\u0001"`},
+       {"\x02", `"\u0002"`},
+       {"\x03", `"\u0003"`},
+       {"\x04", `"\u0004"`},
+       {"\x05", `"\u0005"`},
+       {"\x06", `"\u0006"`},
+       {"\x07", `"\u0007"`},
+       {"\x08", `"\u0008"`},
+       {"\x09", `"\t"`},
+       {"\x0a", `"\n"`},
+       {"\x0b", `"\u000b"`},
+       {"\x0c", `"\u000c"`},
+       {"\x0d", `"\r"`},
+       {"\x0e", `"\u000e"`},
+       {"\x0f", `"\u000f"`},
+       {"\x10", `"\u0010"`},
+       {"\x11", `"\u0011"`},
+       {"\x12", `"\u0012"`},
+       {"\x13", `"\u0013"`},
+       {"\x14", `"\u0014"`},
+       {"\x15", `"\u0015"`},
+       {"\x16", `"\u0016"`},
+       {"\x17", `"\u0017"`},
+       {"\x18", `"\u0018"`},
+       {"\x19", `"\u0019"`},
+       {"\x1a", `"\u001a"`},
+       {"\x1b", `"\u001b"`},
+       {"\x1c", `"\u001c"`},
+       {"\x1d", `"\u001d"`},
+       {"\x1e", `"\u001e"`},
+       {"\x1f", `"\u001f"`},
+}
+
+func TestEncodeString(t *testing.T) {
+       for _, tt := range encodeStringTests {
+               b, err := Marshal(tt.in)
+               if err != nil {
+                       t.Errorf("Marshal(%q): %v", tt.in, err)
+                       continue
+               }
+               out := string(b)
+               if out != tt.out {
+                       t.Errorf("Marshal(%q) = %#q, want %#q", tt.in, out, tt.out)
+               }
+       }
+}