Decode: allow \r\n as line whitespace before \ (#709)

Fixes #708

parser.go

@@ -578,6 +578,10 @@ func (p *parser) parseMultilineBasicString(b []byte) ([]byte, []byte, []byte, er
 				switch token[i+j] {
 				case ' ', '\t':
 					continue
+				case '\r':
+					if token[i+j+1] == '\n' {
+						continue
+					}
 				case '\n':
 					isLastNonWhitespaceOnLine = true
 				}

unmarshaler_test.go

@@ -2304,6 +2304,13 @@ func TestIssue703(t *testing.T) {
 	require.Error(t, err)
 }
 
+func TestIssue708(t *testing.T) {
+	v := map[string]string{}
+	err := toml.Unmarshal([]byte("0=\"\"\"\\\r\n\"\"\""), &v)
+	require.NoError(t, err)
+	require.Equal(t, map[string]string{"0": ""}, v)
+}
+
 func TestUnmarshalDecodeErrors(t *testing.T) {
 	examples := []struct {
 		desc string