registry: use len(via)!=0 instead of via!=nil
This avoids the corner case where `via` is not nil, but has a length of 0,
so the updated code does not panic in that situation.
@@ -145,7 +145,7 @@ func trustedLocation(req *http.Request) bool {
// addRequiredHeadersToRedirectedRequests adds the necessary redirection headers
// for redirected requests
func addRequiredHeadersToRedirectedRequests(req *http.Request, via []*http.Request) error {
- if via != nil && via[0] != nil {
+ if len(via) != 0 && via[0] != nil {
if trustedLocation(req) && trustedLocation(via[0]) {
req.Header = via[0].Header
return nil
