refs #5896 this fixes some tests

core/DataTable.php

@@ -1634,6 +1634,9 @@ class DataTable implements DataTableInterface, \IteratorAggregate
         $thisRow->sumRow($row, $copyMeta = true, $this->getMetadata(self::COLUMN_AGGREGATION_OPS_METADATA_NAME));
     }
 
+    /**
+     * @return \ArrayIterator|Row[]
+     */
     public function getIterator() {
         return new \ArrayIterator($this->rows);
     }

core/DataTable/Filter/ColumnDelete.php

@@ -100,7 +100,7 @@ class ColumnDelete extends BaseFilter
 
         // remove columns specified in $this->columnsToRemove
         if (!empty($this->columnsToRemove)) {
-            foreach ($table as $row) {
+            foreach ($table as &$row) {
                 foreach ($this->columnsToRemove as $column) {
                     if ($this->deleteIfZeroOnly) {
                         $value = $row[$column];
@@ -118,7 +118,7 @@ class ColumnDelete extends BaseFilter
 
         // remove columns not specified in $columnsToKeep
         if (!empty($this->columnsToKeep)) {
-            foreach ($table as $row) {
+            foreach ($table as &$row) {
                 foreach ($row as $name => $value) {
 
                     $keep = false;

plugins/API/tests/RssRendererTest.php

@@ -155,7 +155,7 @@ class RssRendererTest extends \DatabaseTestCase
     <title>piwik statistics - RSS</title>
     <link>http://piwik.org</link>
     <description>Piwik RSS feed</description>
-
+    
     <generator>piwik</generator>
     <language>en</language>
     	</channel>