Allow whitespace after chunk size

There seems to be servers/load balancers that insert whitespaces
between the chunk-size number and \r\n.

http.go

@@ -1679,14 +1679,21 @@ func parseChunkSize(r *bufio.Reader) (int, error) {
 	if err != nil {
 		return -1, err
 	}
-	c, err := r.ReadByte()
-	if err != nil {
-		return -1, fmt.Errorf("cannot read '\r' char at the end of chunk size: %s", err)
-	}
-	if c != '\r' {
-		return -1, fmt.Errorf("unexpected char %q at the end of chunk size. Expected %q", c, '\r')
+	for {
+		c, err := r.ReadByte()
+		if err != nil {
+			return -1, fmt.Errorf("cannot read '\r' char at the end of chunk size: %s", err)
+		}
+		// Skip any trailing whitespace after chunk size.
+		if c == ' ' {
+			continue
+		}
+		if c != '\r' {
+			return -1, fmt.Errorf("unexpected char %q at the end of chunk size. Expected %q", c, '\r')
+		}
+		break
 	}
-	c, err = r.ReadByte()
+	c, err := r.ReadByte()
 	if err != nil {
 		return -1, fmt.Errorf("cannot read '\n' char at the end of chunk size: %s", err)
 	}

http_test.go

@@ -1300,6 +1300,23 @@ func TestRequestReadChunked(t *testing.T) {
 	verifyTrailer(t, rb, "trail")
 }
 
+// See: https://github.com/erikdubbelboer/fasthttp/issues/34
+func TestRequestChunkedWhitespace(t *testing.T) {
+	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\n3  \r\nabc\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: %s", err)
+	}
+	expectedBody := "abc"
+	if string(req.Body()) != expectedBody {
+		t.Fatalf("Unexpected body %q. Expected %q", req.Body(), expectedBody)
+	}
+}
+
 func TestResponseReadWithoutBody(t *testing.T) {
 	var resp Response