1 files changed, 72 insertions, 29 deletions

diff --git a/libgo/go/net/http/transfer.go b/libgo/go/net/http/transfer.go
index 2eec9d9abc4..7f63686528a 100644
--- a/libgo/go/net/http/transfer.go
+++ b/libgo/go/net/http/transfer.go
@@ -12,11 +12,20 @@ import (
 	"io"
 	"io/ioutil"
 	"net/textproto"
+	"sort"
 	"strconv"
 	"strings"
 	"sync"
 )
 
+type errorReader struct {
+	err error
+}
+
+func (r *errorReader) Read(p []byte) (n int, err error) {
+	return 0, r.err
+}
+
 // transferWriter inspects the fields of a user-supplied Request or Response,
 // sanitizes them without changing the user object and provides methods for
 // writing the respective header, body and trailer in wire format.
@@ -53,8 +62,11 @@ func newTransferWriter(r interface{}) (t *transferWriter, err error) {
 			if t.ContentLength == 0 {
 				// Test to see if it's actually zero or just unset.
 				var buf [1]byte
-				n, _ := io.ReadFull(t.Body, buf[:])
-				if n == 1 {
+				n, rerr := io.ReadFull(t.Body, buf[:])
+				if rerr != nil && rerr != io.EOF {
+					t.ContentLength = -1
+					t.Body = &errorReader{rerr}
+				} else if n == 1 {
 					// Oh, guess there is data in this Body Reader after all.
 					// The ContentLength field just wasn't set.
 					// Stich the Body back together again, re-attaching our
@@ -132,11 +144,10 @@ func (t *transferWriter) shouldSendContentLength() bool {
 	return false
 }
 
-func (t *transferWriter) WriteHeader(w io.Writer) (err error) {
+func (t *transferWriter) WriteHeader(w io.Writer) error {
 	if t.Close {
-		_, err = io.WriteString(w, "Connection: close\r\n")
-		if err != nil {
-			return
+		if _, err := io.WriteString(w, "Connection: close\r\n"); err != nil {
+			return err
 		}
 	}
 
@@ -144,43 +155,44 @@ func (t *transferWriter) WriteHeader(w io.Writer) (err error) {
 	// function of the sanitized field triple (Body, ContentLength,
 	// TransferEncoding)
 	if t.shouldSendContentLength() {
-		io.WriteString(w, "Content-Length: ")
-		_, err = io.WriteString(w, strconv.FormatInt(t.ContentLength, 10)+"\r\n")
-		if err != nil {
-			return
+		if _, err := io.WriteString(w, "Content-Length: "); err != nil {
+			return err
+		}
+		if _, err := io.WriteString(w, strconv.FormatInt(t.ContentLength, 10)+"\r\n"); err != nil {
+			return err
 		}
 	} else if chunked(t.TransferEncoding) {
-		_, err = io.WriteString(w, "Transfer-Encoding: chunked\r\n")
-		if err != nil {
-			return
+		if _, err := io.WriteString(w, "Transfer-Encoding: chunked\r\n"); err != nil {
+			return err
 		}
 	}
 
 	// Write Trailer header
 	if t.Trailer != nil {
-		// TODO: At some point, there should be a generic mechanism for
-		// writing long headers, using HTTP line splitting
-		io.WriteString(w, "Trailer: ")
-		needComma := false
+		keys := make([]string, 0, len(t.Trailer))
 		for k := range t.Trailer {
 			k = CanonicalHeaderKey(k)
 			switch k {
 			case "Transfer-Encoding", "Trailer", "Content-Length":
 				return &badStringError{"invalid Trailer key", k}
 			}
-			if needComma {
-				io.WriteString(w, ",")
+			keys = append(keys, k)
+		}
+		if len(keys) > 0 {
+			sort.Strings(keys)
+			// TODO: could do better allocation-wise here, but trailers are rare,
+			// so being lazy for now.
+			if _, err := io.WriteString(w, "Trailer: "+strings.Join(keys, ",")+"\r\n"); err != nil {
+				return err
 			}
-			io.WriteString(w, k)
-			needComma = true
 		}
-		_, err = io.WriteString(w, "\r\n")
 	}
 
-	return
+	return nil
 }
 
-func (t *transferWriter) WriteBody(w io.Writer) (err error) {
+func (t *transferWriter) WriteBody(w io.Writer) error {
+	var err error
 	var ncopy int64
 
 	// Write body
@@ -217,11 +229,16 @@ func (t *transferWriter) WriteBody(w io.Writer) (err error) {
 
 	// TODO(petar): Place trailer writer code here.
 	if chunked(t.TransferEncoding) {
+		// Write Trailer header
+		if t.Trailer != nil {
+			if err := t.Trailer.Write(w); err != nil {
+				return err
+			}
+		}
 		// Last chunk, empty trailer
 		_, err = io.WriteString(w, "\r\n")
 	}
-
-	return
+	return err
 }
 
 type transferReader struct {
@@ -253,6 +270,22 @@ func bodyAllowedForStatus(status int) bool {
 	return true
 }
 
+var (
+	suppressedHeaders304    = []string{"Content-Type", "Content-Length", "Transfer-Encoding"}
+	suppressedHeadersNoBody = []string{"Content-Length", "Transfer-Encoding"}
+)
+
+func suppressedHeaders(status int) []string {
+	switch {
+	case status == 304:
+		// RFC 2616 section 10.3.5: "the response MUST NOT include other entity-headers"
+		return suppressedHeaders304
+	case !bodyAllowedForStatus(status):
+		return suppressedHeadersNoBody
+	}
+	return nil
+}
+
 // msg is *Request or *Response.
 func readTransfer(msg interface{}, r *bufio.Reader) (err error) {
 	t := &transferReader{RequestMethod: "GET"}
@@ -499,7 +532,7 @@ func fixTrailer(header Header, te []string) (Header, error) {
 		case "Transfer-Encoding", "Trailer", "Content-Length":
 			return nil, &badStringError{"bad trailer key", key}
 		}
-		trailer.Del(key)
+		trailer[key] = nil
 	}
 	if len(trailer) == 0 {
 		return nil, nil
@@ -631,13 +664,23 @@ func (b *body) readTrailer() error {
 	}
 	switch rr := b.hdr.(type) {
 	case *Request:
-		rr.Trailer = Header(hdr)
+		mergeSetHeader(&rr.Trailer, Header(hdr))
 	case *Response:
-		rr.Trailer = Header(hdr)
+		mergeSetHeader(&rr.Trailer, Header(hdr))
 	}
 	return nil
 }
 
+func mergeSetHeader(dst *Header, src Header) {
+	if *dst == nil {
+		*dst = src
+		return
+	}
+	for k, vv := range src {
+		(*dst)[k] = vv
+	}
+}
+
 func (b *body) Close() error {
 	b.mu.Lock()
 	defer b.mu.Unlock()