Ensure responses are context.ResponseWriters (#19843) In order for web.Wrap to be able to detect if a response has been written we need to wrap any non-context.ResponseWriters as a such. Otherwise responses will be incorrectly detected as non-written to and handlers can double run. In the case of GZip this handler will change the response to a non-context.RW and this failure to correctly detect response writing causes fallthrough and a NPE. Fix #19839 Signed-off-by: Andrew Thornton <art27@cantab.net>

Changes

1 changed files (+6/-0)

• modules/web/wrap_convert.go
  • @@ -21,6 +21,9 @@ func convertHandler(handler interface{}) wrappedHandlerFunc {
    case http.HandlerFunc: return func(resp http.ResponseWriter, req *http.Request, others ...wrappedHandlerFunc) (done bool, deferrable func()) { routing.UpdateFuncInfo(req.Context(), funcInfo) + if _, ok := resp.(context.ResponseWriter); !ok { + resp = context.NewResponse(resp) + } t(resp, req) if r, ok := resp.(context.ResponseWriter); ok && r.Status() > 0 { done = true
  • @@ -92,6 +95,9 @@ func convertHandler(handler interface{}) wrappedHandlerFunc {
    next = wrapInternal(others) } routing.UpdateFuncInfo(req.Context(), funcInfo) + if _, ok := resp.(context.ResponseWriter); !ok { + resp = context.NewResponse(resp) + } t(next).ServeHTTP(resp, req) if r, ok := resp.(context.ResponseWriter); ok && r.Status() > 0 { done = true