Improve expectation for not modified check in theme/vier/style

- Address https://github.com/friendica/friendica/issues/9252#issuecomment-721994406

diff --git a/view/theme/vier/style.php b/view/theme/vier/style.php
index ac5cd08efb3b0bd13bea1bdb0def39f949209d74..8cd0d7a32aae8921ab67db53ee12faf928a96bb9 100644 (file)
--- a/view/theme/vier/style.php
+++ b/view/theme/vier/style.php
@@ -61,7 +61,7 @@ header('Cache-Control: public');
 header('ETag: "'.$etag.'"');
 header('Last-Modified: '.$modified);
 
-if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) || isset($_SERVER['HTTP_IF_NONE_MATCH'])) {
+if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && isset($_SERVER['HTTP_IF_NONE_MATCH'])) {
        $cached_modified = gmdate('r', strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']));
        $cached_etag = str_replace(['"', "-gzip"], ['', ''],
                                stripslashes($_SERVER['HTTP_IF_NONE_MATCH']));