Replace some characters in Email subject and Email attachments filename

Fixes #9631

core/Mail.php

@@ -127,6 +127,18 @@ class Mail extends Zend_Mail
         }
     }
 
+    public function createAttachment($body, $mimeType = null, $disposition = null, $encoding = null, $filename = null)
+    {
+        $filename = self::sanitiseString($filename);
+        return parent::createAttachment($body, $mimeType, $disposition, $encoding, $filename);
+    }
+
+    public function setSubject($subject)
+    {
+        $subject = self::sanitiseString($subject);
+        return parent::setSubject($subject);
+    }
+
     /**
      * @param string $email
      * @return string
@@ -154,4 +166,18 @@ class Mail extends Zend_Mail
     {
         return isset($url['host']) && !Url::isLocalHost($url['host']);
     }
+
+    /**
+     * Replaces characters known to appear incorrectly in some email clients
+     *
+     * @param $string
+     * @return mixed
+     */
+    static public function sanitiseString($string)
+    {
+        $search = array('–', '’');
+        $replace = array('-', '\'');
+        $string = str_replace($search, $replace, $string);
+        return $string;
+    }
 }

tests/PHPUnit/Integration/MailTest.php

+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+
+namespace Piwik\Tests\Integration;
+
+use Piwik\Mail;
+
+class MailTest extends \PHPUnit_Framework_TestCase
+{
+
+    public function getEmailFilenames()
+    {
+        return array(
+            array('January 3 – 9, 2010', 'January 3 - 9, 2010'),
+            array('Report <The><< ’s Coves - week January 18 – 24, 2016', 'Report <The><< \'s Coves - week January 18 - 24, 2016'),
+        );
+    }
+
+    /**
+     * @dataProvider getEmailFilenames
+     */
+    public function test_EmailFilenamesAreSanitised($raw, $expected)
+    {
+        $this->assertEquals($expected, Mail::sanitiseString($raw));
+    }
+}