Fix case when datatable false

core/ViewDataTable.php

@@ -389,7 +389,7 @@ class ViewDataTable
     {
         if (self::$reportPropertiesCache === null) {
             self::$reportPropertiesCache = array();
-            Piwik_PostEvent('ViewDataTable.getReportDisplayProperties', array(&self::$reportPropertiesCache));
+            Piwik_PostEvent('ViewDataTable.getReportDisplayProperties', array(self::$reportPropertiesCache));
         }
 
         return self::$reportPropertiesCache;
@@ -952,8 +952,8 @@ class ViewDataTable
 
         if ($strPeriod !== false
             && $strDate !== false
-            && (is_null($this->dataTable) || $this->dataTable->getRowsCount() == 0)
-        ) {
+            && (is_null($this->dataTable)
+                || (!empty($this->dataTable) && $this->dataTable->getRowsCount() == 0))) {
             // if range, only look at the first date
             if ($strPeriod == 'range') {
                 $idSite = Common::getRequestVar('idSite', '');