diff --git a/core/DataTable.php b/core/DataTable.php
index 1e594e4e41e19748679220b45fb9990215dce081..7bf7cceef5170705fd8a6f3a042f791e8438e771 100644
--- a/core/DataTable.php
+++ b/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);
     }
diff --git a/core/DataTable/Filter/ColumnDelete.php b/core/DataTable/Filter/ColumnDelete.php
index f9f9773af8204df4f72be491ac75864c011b97f2..532cd5c644685e7ef9acfcefb5b33dc2753b7d3a 100644
--- a/core/DataTable/Filter/ColumnDelete.php
+++ b/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;
diff --git a/plugins/API/tests/RssRendererTest.php b/plugins/API/tests/RssRendererTest.php
index 1145ce3da9b4921d73f1c526623fc4899b252b69..175699fca3bd98f5a0fef0d61cb06c581030f5fb 100644
--- a/plugins/API/tests/RssRendererTest.php
+++ b/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>