Handle \r as a whitespace when parsing JSON string.

Fixes #272.

R=rsc
https://golang.org/cl/161061

src/pkg/json/parse.go

@@ -198,7 +198,7 @@ func punct(c byte) bool {
 	return c == '"' || c == '[' || c == ']' || c == ':' || c == '{' || c == '}' || c == ','
 }
 
-func white(c byte) bool	{ return c == ' ' || c == '\t' || c == '\n' || c == '\v' }
+func white(c byte) bool	{ return c == ' ' || c == '\t' || c == '\r' || c == '\n' || c == '\v' }
 
 func skipwhite(p string, i int) int {
 	for i < len(p) && white(p[i]) {

src/pkg/json/struct_test.go

@@ -66,6 +66,17 @@ func check(t *testing.T, ok bool, name string, v interface{}) {
 	}
 }
 
+const whiteSpaceEncoded = " \t{\n\"s\"\r:\"string\"\v}"
+
+func TestUnmarshalWhitespace(t *testing.T) {
+	var m myStruct;
+	ok, errtok := Unmarshal(whiteSpaceEncoded, &m);
+	if !ok {
+		t.Fatalf("Unmarshal failed near %s", errtok)
+	}
+	check(t, m.S == "string", "string", m.S);
+}
+
 func TestUnmarshal(t *testing.T) {
 	var m myStruct;
 	m.F = true;