Fixed Fix count() on NULL

src/PHPExcel.php

@@ -177,10 +177,11 @@ not set to TRUE. Excel export aborted.");
     // Make sure we have an ignore_headers key to prevent Notices.
     $options['ignore_headers'] = $options['ignore_headers'] ?? empty($headers);
 
-    if (!count($data)) {
-      $this->logger->error("No data was provided. Excel export aborted.");
-
-      return self::PHPEXCEL_ERROR_NO_DATA;
+    if (isset($data) && (is_array($data) || is_countable($data))) {
+      if (count($data) === 0) {
+          $this->logger->error("No data was provided. Excel export aborted.");
+          return self::PHPEXCEL_ERROR_NO_DATA;
+      }
     }
 
     if (!(is_writable($path) || (!file_exists($path) && is_writable(dirname($path))))) {