1 files changed, 26 insertions, 2 deletions
diff --git a/libgo/go/net/net.go b/libgo/go/net/net.go
index 77b8f69074e..b3f9b8ba07f 100644
--- a/libgo/go/net/net.go
+++ b/libgo/go/net/net.go
@@ -282,7 +282,7 @@ func (c *conn) SetWriteBuffer(bytes int) error {
 	return nil
 }
 
-// File returns a copy of the underlying os.File
+// File returns a copy of the underlying os.File.
 // It is the caller's responsibility to close f when finished.
 // Closing c does not affect f, and closing f does not affect c.
 //
@@ -448,6 +448,8 @@ type OpError struct {
 	Err error
 }
 
+func (e *OpError) Unwrap() error { return e.Err }
+
 func (e *OpError) Error() string {
 	if e == nil {
 		return "<nil>"
@@ -473,7 +475,7 @@ func (e *OpError) Error() string {
 
 var (
 	// aLongTimeAgo is a non-zero time, far in the past, used for
-	// immediate cancelation of dials.
+	// immediate cancellation of dials.
 	aLongTimeAgo = time.Unix(1, 0)
 
 	// nonDeadline and noCancel are just zero values for
@@ -514,6 +516,16 @@ func (e *OpError) Temporary() bool {
 	return ok && t.Temporary()
 }
 
+func (e *OpError) Is(target error) bool {
+	switch target {
+	case os.ErrTemporary:
+		return e.Temporary()
+	case os.ErrTimeout:
+		return e.Timeout()
+	}
+	return false
+}
+
 // A ParseError is the error type of literal network address parsers.
 type ParseError struct {
 	// Type is the type of string that was expected, such as
@@ -563,6 +575,7 @@ type DNSConfigError struct {
 	Err error
 }
 
+func (e *DNSConfigError) Unwrap() error   { return e.Err }
 func (e *DNSConfigError) Error() string   { return "error reading DNS config: " + e.Err.Error() }
 func (e *DNSConfigError) Timeout() bool   { return false }
 func (e *DNSConfigError) Temporary() bool { return false }
@@ -579,6 +592,7 @@ type DNSError struct {
 	Server      string // server used
 	IsTimeout   bool   // if true, timed out; not all timeouts set this
 	IsTemporary bool   // if true, error is temporary; not all errors set this
+	IsNotFound  bool   // if true, host could not be found
 }
 
 func (e *DNSError) Error() string {
@@ -603,6 +617,16 @@ func (e *DNSError) Timeout() bool { return e.IsTimeout }
 // error and return a DNSError for which Temporary returns false.
 func (e *DNSError) Temporary() bool { return e.IsTimeout || e.IsTemporary }
 
+func (e *DNSError) Is(target error) bool {
+	switch target {
+	case os.ErrTemporary:
+		return e.Temporary()
+	case os.ErrTimeout:
+		return e.Timeout()
+	}
+	return false
+}
+
 type writerOnly struct {
 	io.Writer
 }