5 files changed, 22 insertions, 6 deletions

diff --git a/core/DataTable/DataTableInterface.php b/core/DataTable/DataTableInterface.php
index 84440dfa24..7009be7285 100644
--- a/core/DataTable/DataTableInterface.php
+++ b/core/DataTable/DataTableInterface.php
@@ -27,4 +27,5 @@ interface DataTableInterface
     public function deleteColumn($name);
     public function getColumn($name);
     public function getColumns();
+    public function deleteRowsMetadata($name, $deleteRecursiveInSubtables = false);
 }
diff --git a/core/DataTable/Map.php b/core/DataTable/Map.php
index 9169a36128..351cb4d058 100644
--- a/core/DataTable/Map.php
+++ b/core/DataTable/Map.php
@@ -11,7 +11,6 @@ namespace Piwik\DataTable;
 use Closure;
 use Piwik\Common;
 use Piwik\DataTable;
-use Piwik\DataTable\Renderer\Console;
 use Piwik\DataTable\Renderer\Html;
 
 /**
@@ -514,6 +513,19 @@ class Map implements DataTableInterface
     }
 
     /**
+     * Delete row metadata by name in every row.
+     *
+     * @param       $name
+     * @param bool $deleteRecursiveInSubtables
+     */
+    public function deleteRowsMetadata($name, $deleteRecursiveInSubtables = false)
+    {
+        foreach ($this->getDataTables() as $table) {
+            $table->deleteRowsMetadata($name, $deleteRecursiveInSubtables);
+        }
+    }
+
+    /**
      * See {@link DataTable::getColumns()}.
      *
      * @return array
diff --git a/core/DataTable/Renderer/Csv.php b/core/DataTable/Renderer/Csv.php
index bf864238e5..b67150d2fd 100644
--- a/core/DataTable/Renderer/Csv.php
+++ b/core/DataTable/Renderer/Csv.php
@@ -489,7 +489,7 @@ class Csv extends Renderer
     protected function removeFirstPercentSign($value)
     {
         $needle = '%';
-        $posPercent = strpos($value, $needle);
+        $posPercent = strpos($value ?? '', $needle);
         if ($posPercent !== false) {
             return substr_replace($value, '', $posPercent, strlen($needle));
         }
diff --git a/core/DataTable/Renderer/Xml.php b/core/DataTable/Renderer/Xml.php
index 1fd09f938e..daac728652 100644
--- a/core/DataTable/Renderer/Xml.php
+++ b/core/DataTable/Renderer/Xml.php
@@ -179,7 +179,7 @@ class Xml extends Renderer
             } else {
                 $xmlValue = self::formatValueXml($value);
 
-                if (strlen($xmlValue) != 0) {
+                if (strlen(strval($xmlValue)) !== 0) {
                     $result .= $prefixLines . $prefix . $xmlValue . $suffix . "\n";
                 } else {
                     $result .= $prefixLines . $emptyNode . "\n";
@@ -381,7 +381,7 @@ class Xml extends Renderer
 
                     list($tagStart, $tagEnd) = $this->getTagStartAndEndFor($name, $columnsHaveInvalidChars);
 
-                    if (strlen($value) == 0) {
+                    if (strlen((string) $value) == 0) {
                         $out .= $prefixLine . "\t\t<$tagStart />\n";
                     } else {
                         $out .= $prefixLine . "\t\t<$tagStart>" . $value . "</$tagEnd>\n";
diff --git a/core/DataTable/Row.php b/core/DataTable/Row.php
index bfa1a49667..878c1a61cf 100644
--- a/core/DataTable/Row.php
+++ b/core/DataTable/Row.php
@@ -12,7 +12,6 @@ use Exception;
 use Piwik\Container\StaticContainer;
 use Piwik\DataTable;
 use Piwik\Date;
-use Piwik\Log;
 use Piwik\Metrics;
 use Piwik\Period;
 use Psr\Log\LoggerInterface;
@@ -36,7 +35,8 @@ class Row extends \ArrayObject
      */
     private static $unsummableColumns = array(
         'label' => true,
-        'full_url' => true // column used w/ old Piwik versions,
+        'full_url' => true, // column used w/ old Piwik versions,
+        'ts_archived' => true // date column used in metadata for proportional tooltips
     );
 
     // @see sumRow - implementation detail
@@ -677,6 +677,9 @@ class Row extends \ArrayObject
         if (is_array($columnToSumValue)) {
             $newValue = $thisColumnValue;
             foreach ($columnToSumValue as $arrayIndex => $arrayValue) {
+                if (!is_numeric($arrayIndex) && !$this->isSummableColumn($arrayIndex)) {
+                    continue;
+                }
                 if (!isset($newValue[$arrayIndex])) {
                     $newValue[$arrayIndex] = false;
                 }