Issue #1328696 by Tor Arne Thune, wojtha, MaxMendez: Fixed Problem with...

Issue #1328696 by Tor Arne Thune, wojtha, MaxMendez: Fixed Problem with _drupal_wrap_mail_line() and attachment files.

core/includes/mail.inc

@@ -520,10 +520,36 @@ function drupal_html_to_text($string, $allowed_tags = NULL) {
  * Wraps words on a single line.
  *
  * Callback for array_walk() winthin drupal_wrap_mail().
+ *
+ * Note that we are skipping MIME content header lines, because attached files,
+ * especially applications, could have long MIME types or long filenames which
+ * result in line length longer than the 77 characters limit and wrapping that
+ * line will break the e-mail format. E.g., the attached file hello_drupal.docx
+ * will produce the following Content-Type:
+ * Content-Type:
+ * application/vnd.openxmlformats-officedocument.wordprocessingml.document;
+ * name="hello_drupal.docx"
  */
 function _drupal_wrap_mail_line(&$line, $key, $values) {
-  // Use soft-breaks only for purely quoted or unindented text.
-  $line = wordwrap($line, 77 - $values['length'], $values['soft'] ? "  \n" : "\n");
+  $line_is_mime_header = FALSE;
+  $mime_headers = array(
+    'Content-Type',
+    'Content-Transfer-Encoding',
+    'Content-Disposition',
+    'Content-Description',
+  );
+
+  // Do not break MIME headers which could be longer than 77 characters.
+  foreach ($mime_headers as $header) {
+    if (strpos($line, $header . ': ') === 0) {
+      $line_is_mime_header = TRUE;
+      break;
+    }
+  }
+  if (!$line_is_mime_header) {
+    // Use soft-breaks only for purely quoted or unindented text.
+    $line = wordwrap($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");
 }

core/modules/system/lib/Drupal/system/Tests/Mail/WrapMailUnitTest.php

+<?php
+
+/**
+ * @file
+ * Definition of Drupal\system\Tests\Mail\WrapMailUnitTest.
+ */
+
+namespace Drupal\system\Tests\Mail;
+
+use Drupal\simpletest\UnitTestBase;
+
+/**
+ * Tests the functionality of drupal_wrap_mail().
+ */
+class WrapMailUnitTest extends UnitTestBase {
+
+  public static function getInfo() {
+    return array(
+      'name'  => 'Mail wrapping',
+      'description' => 'Tests drupal_wrap_mail().',
+      'group' => 'Mail',
+    );
+  }
+
+  /**
+   * Makes sure that drupal_wrap_mail() wraps the correct types of lines.
+   */
+  function testDrupalWrapMail() {
+    $delimiter = "End of header\n";
+    $long_file_name = $this->randomName(64) . '.docx';
+    $headers_in_body = 'Content-Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document; name="' . $long_file_name . "\"\n";
+    $headers_in_body .= "Content-Transfer-Encoding: base64\n";
+    $headers_in_body .= 'Content-Disposition: attachment; filename="' . $long_file_name . "\"\n";
+    $headers_in_body .= 'Content-Description: ' . $this->randomName(64);
+    $body = $this->randomName(76) . ' ' . $this->randomName(6);
+    $wrapped_text = drupal_wrap_mail($headers_in_body . $delimiter . $body);
+    list($processed_headers, $processed_body) = explode($delimiter, $wrapped_text);
+
+    // Check that the body headers were not wrapped even though some exceeded
+    // 77 characters.
+    $this->assertEqual($headers_in_body, $processed_headers, 'Headers in the body are not wrapped.');
+    // Check that the body text is wrapped.
+    $this->assertEqual(wordwrap($body, 77, "  \n"), $processed_body, 'Body text is wrapped.');
+  }
+}
+