libgo: update to Go 1.13beta1 release

    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/193497

From-SVN: r275473

1 files changed, 16 insertions, 6 deletions

diff --git a/libgo/go/math/big/intconv.go b/libgo/go/math/big/intconv.go
index 6cca827..0567284 100644
--- a/libgo/go/math/big/intconv.go
+++ b/libgo/go/math/big/intconv.go
@@ -16,7 +16,8 @@ import (
 // Base must be between 2 and 62, inclusive. The result uses the
 // lower-case letters 'a' to 'z' for digit values 10 to 35, and
 // the upper-case letters 'A' to 'Z' for digit values 36 to 61.
-// No prefix (such as "0x") is added to the string.
+// No prefix (such as "0x") is added to the string. If x is a nil
+// pointer it returns "<nil>".
 func (x *Int) Text(base int) string {
 	if x == nil {
 		return "<nil>"
@@ -33,6 +34,8 @@ func (x *Int) Append(buf []byte, base int) []byte {
 	return append(buf, x.abs.itoa(x.neg, base)...)
 }
 
+// String returns the decimal representation of x as generated by
+// x.Text(10).
 func (x *Int) String() string {
 	return x.Text(10)
 }
@@ -50,8 +53,9 @@ func writeMultiple(s fmt.State, text string, count int) {
 var _ fmt.Formatter = intOne // *Int must implement fmt.Formatter
 
 // Format implements fmt.Formatter. It accepts the formats
-// 'b' (binary), 'o' (octal), 'd' (decimal), 'x' (lowercase
-// hexadecimal), and 'X' (uppercase hexadecimal).
+// 'b' (binary), 'o' (octal with 0 prefix), 'O' (octal with 0o prefix),
+// 'd' (decimal), 'x' (lowercase hexadecimal), and
+// 'X' (uppercase hexadecimal).
 // Also supported are the full suite of package fmt's format
 // flags for integral types, including '+' and ' ' for sign
 // control, '#' for leading zero in octal and for hexadecimal,
@@ -66,7 +70,7 @@ func (x *Int) Format(s fmt.State, ch rune) {
 	switch ch {
 	case 'b':
 		base = 2
-	case 'o':
+	case 'o', 'O':
 		base = 8
 	case 'd', 's', 'v':
 		base = 10
@@ -98,6 +102,8 @@ func (x *Int) Format(s fmt.State, ch rune) {
 	prefix := ""
 	if s.Flag('#') {
 		switch ch {
+		case 'b': // binary
+			prefix = "0b"
 		case 'o': // octal
 			prefix = "0"
 		case 'x': // hexadecimal
@@ -106,6 +112,9 @@ func (x *Int) Format(s fmt.State, ch rune) {
 			prefix = "0X"
 		}
 	}
+	if ch == 'O' {
+		prefix = "0o"
+	}
 
 	digits := x.abs.utoa(base)
 	if ch == 'X' {
@@ -166,8 +175,9 @@ func (x *Int) Format(s fmt.State, ch rune) {
 //
 // The base argument must be 0 or a value from 2 through MaxBase. If the base
 // is 0, the string prefix determines the actual conversion base. A prefix of
-// ``0x'' or ``0X'' selects base 16; the ``0'' prefix selects base 8, and a
-// ``0b'' or ``0B'' prefix selects base 2. Otherwise the selected base is 10.
+// ``0b'' or ``0B'' selects base 2; a ``0'', ``0o'', or ``0O'' prefix selects
+// base 8, and a ``0x'' or ``0X'' prefix selects base 16. Otherwise the selected
+// base is 10.
 //
 func (z *Int) scan(r io.ByteScanner, base int) (*Int, int, error) {
 	// determine sign