Fixed transfer-encoding for empty chunked payload (#1536)

http.go

@@ -1268,7 +1268,7 @@ func (req *Request) ContinueReadBody(r *bufio.Reader, maxBodySize int, preParseM
 		return err
 	}
 
-	if req.Header.ContentLength() == -1 {
+	if contentLength == -1 {
 		err = req.Header.ReadTrailer(r)
 		if err != nil && err != io.EOF {
 			return err
@@ -1290,6 +1290,9 @@ func (req *Request) ReadBody(r *bufio.Reader, contentLength int, maxBodySize int
 
 	} else if contentLength == -1 {
 		bodyBuf.B, err = readBodyChunked(r, maxBodySize, bodyBuf.B)
+		if err == nil && len(bodyBuf.B) == 0 {
+			req.Header.SetContentLength(0)
+		}
 
 	} else {
 		bodyBuf.B, err = readBodyIdentity(r, maxBodySize, bodyBuf.B)

http_test.go

@@ -2011,6 +2011,25 @@ func TestRequestReadChunked(t *testing.T) {
 	verifyTrailer(t, rb, map[string]string{"Trail": "test"}, true)
 }
 
+func TestRequestChunkedEmpty(t *testing.T) {
+	t.Parallel()
+
+	var req Request
+
+	s := "POST /foo HTTP/1.1\r\nHost: google.com\r\nTransfer-Encoding: chunked\r\nContent-Type: aa/bb\r\n\r\n0\r\n\r\n"
+	r := bytes.NewBufferString(s)
+	rb := bufio.NewReader(r)
+	err := req.Read(rb)
+	if err != nil {
+		t.Fatalf("Unexpected error when reading chunked request: %v", err)
+	}
+	expectedBody := ""
+	if string(req.Body()) != expectedBody {
+		t.Fatalf("Unexpected body %q. Expected %q", req.Body(), expectedBody)
+	}
+	expectRequestHeaderGet(t, &req.Header, HeaderTransferEncoding, "")
+}
+
 // See: https://github.com/erikdubbelboer/fasthttp/issues/34
 func TestRequestChunkedWhitespace(t *testing.T) {
 	t.Parallel()