Fix backspace and form-feed for Go 1.22

Encode \b and \f in JSON string as themselves

gjson.go

@@ -1926,6 +1926,10 @@ func AppendJSONString(dst []byte, s string) []byte {
 		if s[i] < ' ' {
 			dst = append(dst, '\\')
 			switch s[i] {
+			case '\b':
+				dst = append(dst, 'b')
+			case '\f':
+				dst = append(dst, 'f')
 			case '\n':
 				dst = append(dst, 'n')
 			case '\r':

gjson_test.go

@@ -2578,14 +2578,19 @@ func TestJSONString(t *testing.T) {
 	testJSONString(t, s)
 	testJSONString(t, "R\xfd\xfc\a!\x82eO\x16?_\x0f\x9ab\x1dr")
 	testJSONString(t, "_\xb9\v\xad\xb3|X!\xb6\xd9U&\xa4\x1a\x95\x04")
-	rng := rand.New(rand.NewSource(time.Now().UnixNano()))
-	start := time.Now()
-	var buf [16]byte
-	for time.Since(start) < time.Second*2 {
-		if _, err := rng.Read(buf[:]); err != nil {
-			t.Fatal(err)
+	data, _ := json.Marshal("\b\f")
+	if (string(data) == "\"\\b\\f\"") {
+		// Go version 1.22+ encodes "\b" and "\f" correctly.
+		testJSONString(t, "\b\f")
+		rng := rand.New(rand.NewSource(time.Now().UnixNano()))
+		start := time.Now()
+		var buf [16]byte
+		for time.Since(start) < time.Second*2 {
+			if _, err := rng.Read(buf[:]); err != nil {
+				t.Fatal(err)
+			}
+			testJSONString(t, string(buf[:]))
 		}
-		testJSONString(t, string(buf[:]))
 	}
 }