libgo: update to Go1.14beta1

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/214297

3 files changed, 32 insertions, 10 deletions

diff --git a/libgo/go/fmt/errors_test.go b/libgo/go/fmt/errors_test.go
index 0c774bc..481a7b8 100644
--- a/libgo/go/fmt/errors_test.go
+++ b/libgo/go/fmt/errors_test.go
@@ -11,6 +11,10 @@ import (
 )
 
 func TestErrorf(t *testing.T) {
+	// noVetErrorf is an alias for fmt.Errorf that does not trigger vet warnings for
+	// %w format strings.
+	noVetErrorf := fmt.Errorf
+
 	wrapped := errors.New("inner error")
 	for _, test := range []struct {
 		err        error
@@ -46,13 +50,13 @@ func TestErrorf(t *testing.T) {
 		err:      fmt.Errorf("%v with added context", wrapped),
 		wantText: "inner error with added context",
 	}, {
-		err:      fmt.Errorf("%w is not an error", "not-an-error"),
+		err:      noVetErrorf("%w is not an error", "not-an-error"),
 		wantText: "%!w(string=not-an-error) is not an error",
 	}, {
-		err:      fmt.Errorf("wrapped two errors: %w %w", errString("1"), errString("2")),
+		err:      noVetErrorf("wrapped two errors: %w %w", errString("1"), errString("2")),
 		wantText: "wrapped two errors: 1 %!w(fmt_test.errString=2)",
 	}, {
-		err:      fmt.Errorf("wrapped three errors: %w %w %w", errString("1"), errString("2"), errString("3")),
+		err:      noVetErrorf("wrapped three errors: %w %w %w", errString("1"), errString("2"), errString("3")),
 		wantText: "wrapped three errors: 1 %!w(fmt_test.errString=2) %!w(fmt_test.errString=3)",
 	}, {
 		err:        fmt.Errorf("%w", nil),
diff --git a/libgo/go/fmt/scan.go b/libgo/go/fmt/scan.go
index 0dab2c9..8cab018 100644
--- a/libgo/go/fmt/scan.go
+++ b/libgo/go/fmt/scan.go
@@ -940,6 +940,15 @@ const (
 	uintptrBits = 32 << (^uintptr(0) >> 63)
 )
 
+// scanPercent scans a literal percent character.
+func (s *ss) scanPercent() {
+	s.SkipSpace()
+	s.notEOF()
+	if !s.accept("%") {
+		s.errorString("missing literal %")
+	}
+}
+
 // scanOne scans a single value, deriving the scanner from the type of the argument.
 func (s *ss) scanOne(verb rune, arg interface{}) {
 	s.buf = s.buf[:0]
@@ -1203,6 +1212,10 @@ func (s *ss) doScanf(format string, a []interface{}) (numProcessed int, err erro
 		if c != 'c' {
 			s.SkipSpace()
 		}
+		if c == '%' {
+			s.scanPercent()
+			continue // Do not consume an argument.
+		}
 		s.argLimit = s.limit
 		if f := s.count + s.maxWid; f < s.argLimit {
 			s.argLimit = f
diff --git a/libgo/go/fmt/scan_test.go b/libgo/go/fmt/scan_test.go
index b14a6f5..1cc469c 100644
--- a/libgo/go/fmt/scan_test.go
+++ b/libgo/go/fmt/scan_test.go
@@ -318,13 +318,15 @@ var scanfTests = []ScanfTest{
 	{"%2s", "sssss", &xVal, Xs("ss")},
 
 	// Fixed bugs
-	{"%d\n", "27\n", &intVal, 27},      // ok
-	{"%d\n", "28 \n", &intVal, 28},     // was: "unexpected newline"
-	{"%v", "0", &intVal, 0},            // was: "EOF"; 0 was taken as base prefix and not counted.
-	{"%v", "0", &uintVal, uint(0)},     // was: "EOF"; 0 was taken as base prefix and not counted.
-	{"%c", " ", &uintVal, uint(' ')},   // %c must accept a blank.
-	{"%c", "\t", &uintVal, uint('\t')}, // %c must accept any space.
-	{"%c", "\n", &uintVal, uint('\n')}, // %c must accept any space.
+	{"%d\n", "27\n", &intVal, 27},         // ok
+	{"%d\n", "28 \n", &intVal, 28},        // was: "unexpected newline"
+	{"%v", "0", &intVal, 0},               // was: "EOF"; 0 was taken as base prefix and not counted.
+	{"%v", "0", &uintVal, uint(0)},        // was: "EOF"; 0 was taken as base prefix and not counted.
+	{"%c", " ", &uintVal, uint(' ')},      // %c must accept a blank.
+	{"%c", "\t", &uintVal, uint('\t')},    // %c must accept any space.
+	{"%c", "\n", &uintVal, uint('\n')},    // %c must accept any space.
+	{"%d%%", "23%\n", &uintVal, uint(23)}, // %% matches literal %.
+	{"%%%d", "%23\n", &uintVal, uint(23)}, // %% matches literal %.
 
 	// space handling
 	{"%d", "27", &intVal, 27},
@@ -467,6 +469,9 @@ var multiTests = []ScanfMultiTest{
 	{"X%d", "10X", args(&intVal), nil, "input does not match format"},
 	{"%d%", "42%", args(&intVal), args(42), "missing verb: % at end of format string"},
 	{"%d% ", "42%", args(&intVal), args(42), "too few operands for format '% '"}, // Slightly odd error, but correct.
+	{"%%%d", "xxx 42", args(&intVal), args(42), "missing literal %"},
+	{"%%%d", "x42", args(&intVal), args(42), "missing literal %"},
+	{"%%%d", "42", args(&intVal), args(42), "missing literal %"},
 
 	// Bad UTF-8: should see every byte.
 	{"%c%c%c", "\xc2X\xc2", args(&r1, &r2, &r3), args(utf8.RuneError, 'X', utf8.RuneError), ""},