Fix handling of blockquote tags with mixed case on html2text conversion (#5363)

CHANGELOG

@@ -27,6 +27,7 @@ CHANGELOG Roundcube Webmail
 - Use contact_search_name format in popup on results in compose contacts search
 - Fix handling of 'mailto' and 'error' arguments in message_before_send hook (#5347)
 - Fix missing localization of HTML editor when assets_dir != INSTALL_PATH
+- Fix handling of blockquote tags with mixed case on html2text conversion (#5363)
 
 RELEASE 1.2.0
 -------------

program/lib/Roundcube/rcube_html2text.php

@@ -587,11 +587,11 @@ class rcube_html2text
     {
         $level = 0;
         $offset = 0;
-        while (($start = strpos($text, '<blockquote', $offset)) !== false) {
+        while (($start = stripos($text, '<blockquote', $offset)) !== false) {
             $offset = $start + 12;
             do {
-                $end = strpos($text, '</blockquote>', $offset);
-                $next = strpos($text, '<blockquote', $offset);
+                $end = stripos($text, '</blockquote>', $offset);
+                $next = stripos($text, '<blockquote', $offset);
 
                 // nested <blockquote>, skip
                 if ($next !== false && $next < $end) {

tests/Framework/Html2text.php

@@ -79,7 +79,7 @@ class rc_html2text extends PHPUnit_Framework_TestCase
     {
         $html = <<<EOF
 <br>Begin<br><blockquote>OUTER BEGIN<blockquote>INNER 1<br></blockquote><div><br></div><div>Par 1</div>
-<blockquote>INNER 2</blockquote><div><br></div><div>Par 2</div>
+<blockQuote>INNER 2</blockquote><div><br></div><div>Par 2</div>
 <div><br></div><div>Par 3</div><div><br></div>
 <blockquote>INNER 3</blockquote>OUTER END</blockquote>
 EOF;