chore: warn on repeated requests only when they succeed (#32403)

plugin/http.go

@@ -226,22 +226,25 @@ func (p *HTTP) request(url string, body string) ([]byte, error) {
 		return nil, err
 	}
 
+	val, err := request.ReadBody(resp)
+	if err != nil {
+		if err2 := knownErrors(val); err2 != nil {
+			err = err2
+		}
+
+		return val, err
+	}
+
 	// warn on uncached GET polling: a repeated roundtrip means neither a configured
 	// cache nor the device's own response headers spared it. cache hits are exempt.
+	// only successful responses count, a failed one is retried by the caller
 	if p.method == http.MethodGet && p.mu == nil && resp.Header.Get(httpcache.XFromCache) == "" {
 		if repeatedGet(url, time.Now()) {
 			p.log.WARN.Printf("uncached request repeated within 1s, please report at https://github.com/evcc-io/evcc/issues: %s", url)
 		}
 	}
 
-	val, err := request.ReadBody(resp)
-	if err != nil {
-		if err2 := knownErrors(val); err2 != nil {
-			err = err2
-		}
-	}
-
-	return val, err
+	return val, nil
 }
 
 type httpAccess struct {

plugin/http_test.go

@@ -164,6 +164,27 @@ func (suite *httpTestSuite) TestSetPath() {
 	suite.Require().Equal("/foo/bar/4711", suite.h.req.URL.String())
 }
 
+func TestRepeatedGetFailed(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		http.Error(w, "nope", http.StatusInternalServerError)
+	}))
+	defer srv.Close()
+
+	p := NewHTTP(util.NewLogger("foo"), http.MethodGet, srv.URL, false, 0)
+	g, err := p.StringGetter()
+	require.NoError(t, err)
+
+	// a failing request is retried by the caller, it must not count as a sighting
+	for range 2 {
+		_, err := g()
+		require.Error(t, err)
+	}
+
+	httpSeenMu.Lock()
+	defer httpSeenMu.Unlock()
+	require.NotContains(t, httpSeen, srv.URL)
+}
+
 func TestRepeatedGet(t *testing.T) {
 	url := "http://repeated.test/uncached"
 	t0 := time.Now()