Cache errors as well

go/favicon/favicon.go

@@ -71,18 +71,26 @@ func GetFaviconCached(u string) (string, error) {
	lock.RUnlock()
	if cached {
		return fu.(string), nil
		switch fu.(type) {
		case string:
			return fu.(string), nil
		case error:
			return "", fu.(error)
		default:
			panic("unexpected type")
		}
	}
	faviconUrl, err := GetFavicon(u)
	if err != nil {
		return faviconUrl, err
	}
	lock.Lock()
	faviconCache.Add(host, faviconUrl)
	if err != nil {
		faviconCache.Add(host, err)
	} else {
		faviconCache.Add(host, faviconUrl)
	}
	lock.Unlock()
	return faviconUrl, nil
	return faviconUrl, err
}
func GetFavicon(url string) (string, error) {