17119: add second test, simplify code by switching to the generic

[arvados.git] / sdk / go / httpserver / responsewriter.go

diff --git a/sdk/go/httpserver/responsewriter.go b/sdk/go/httpserver/responsewriter.go
index 26aee65c5ca0da1f5e23e301aa88024c3fac51b9..049a3f1aae184de0ef522656741494db42764802 100644 (file)
--- a/sdk/go/httpserver/responsewriter.go
+++ b/sdk/go/httpserver/responsewriter.go
@@ -22,7 +22,7 @@ type ResponseWriter interface {
 // error.
 type responseWriter struct {
        http.ResponseWriter
-       wroteStatus    int   // Last status given to WriteHeader()
+       wroteStatus    int   // First status given to WriteHeader()
        wroteBodyBytes int   // Bytes successfully written
        err            error // Last error returned from Write()
        sniffed        []byte
@@ -40,15 +40,21 @@ func (w *responseWriter) CloseNotify() <-chan bool {
 }
 
 func (w *responseWriter) WriteHeader(s int) {
-       w.wroteStatus = s
+       if w.wroteStatus == 0 {
+               w.wroteStatus = s
+       }
+       // ...else it's too late to change the status seen by the
+       // client -- but we call the wrapped WriteHeader() anyway so
+       // it can log a warning.
        w.ResponseWriter.WriteHeader(s)
 }
 
 func (w *responseWriter) Write(data []byte) (n int, err error) {
        if w.wroteStatus == 0 {
                w.WriteHeader(http.StatusOK)
+       } else if w.wroteStatus >= 400 {
+               w.sniff(data)
        }
-       w.sniff(data)
        n, err = w.ResponseWriter.Write(data)
        w.wroteBodyBytes += n
        w.err = err