Issue #1946090 by pjonckiere, alex-mo, rpayanm: _drupal_wrap_mail_line() does...

Issue #1946090 by pjonckiere, alex-mo, rpayanm: _drupal_wrap_mail_line() does not force-wrap too long words after 996 characters

core/lib/Drupal/Core/Mail/MailFormatHelper.php

@@ -327,7 +327,7 @@ protected static function wrapMailLine(&$line, $key, $values) {
       $line = wordwrap($line, 77 - $values['length'], $values['soft'] ? " \n" : "\n");
     }
     // Break really long words at the maximum width allowed.
-    $line = wordwrap($line, 996 - $values['length'], $values['soft'] ? " \n" : "\n");
+    $line = wordwrap($line, 996 - $values['length'], $values['soft'] ? " \n" : "\n", TRUE);
   }
 
   /**

core/modules/system/src/Tests/Mail/HtmlToTextTest.php

@@ -346,7 +346,7 @@ public function testDrupalHtmlToTextParagraphs() {
    * <CRLF> is 1000 characters."
    */
   public function testVeryLongLineWrap() {
-    $input = 'Drupal<br /><p>' . str_repeat('x', 2100) . '</><br />Drupal';
+    $input = 'Drupal<br /><p>' . str_repeat('x', 2100) . '</p><br />Drupal';
     $output = MailFormatHelper::htmlToText($input);
     $eol = Settings::get('mail_line_endings', PHP_EOL);
 
@@ -357,8 +357,7 @@ public function testVeryLongLineWrap() {
       $maximum_line_length = max($maximum_line_length, strlen($line . $eol));
     }
     $verbose = 'Maximum line length found was ' . $maximum_line_length . ' octets.';
-    // @todo This should assert that $maximum_line_length <= 1000.
-    $this->pass($verbose);
+    $this->assertTrue($maximum_line_length <= 1000, $verbose);
   }
 
   /**