Fix handling of message/rfc822 attachments on message forward and edit (#1489214)

CHANGELOG

@@ -1,6 +1,7 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Fix handling of message/rfc822 attachments on message forward and edit (#1489214)
 - Fix folder names truncation in Classic skin (#1489220)
 - Fix parsing of square bracket characters in IMAP response strings (#1489223)
 - Don't clear References and in-Reply-To when a message is "edited as new" (#1489216)

program/steps/mail/compose.inc

@@ -596,15 +596,32 @@ function rcmail_prepare_message_body()
   }
   // reply/edit/draft/forward
   else if ($compose_mode && ($compose_mode != RCUBE_COMPOSE_REPLY || intval($RCMAIL->config->get('reply_mode')) != -1)) {
-    $isHtml = rcmail_compose_editor_mode();
+    $isHtml   = rcmail_compose_editor_mode();
+    $messages = array();
 
     if (!empty($MESSAGE->parts)) {
+      // collect IDs of message/rfc822 parts
+      if ($compose_mode == RCUBE_COMPOSE_EDIT || $compose_mode == RCUBE_COMPOSE_DRAFT) {
+        foreach ($MESSAGE->attachments as $part) {
+          if ($part->mimetype == 'message/rfc822') {
+            $messages[] = $part->mime_id;
+          }
+        }
+      }
+
       foreach ($MESSAGE->parts as $part) {
         // skip no-content and attachment parts (#1488557)
         if ($part->type != 'content' || !$part->size || $MESSAGE->is_attachment($part)) {
           continue;
         }
 
+        // skip all content parts inside the message/rfc822 part in DRAFT/EDIT mode
+        foreach ($messages as $mimeid) {
+          if (strpos($part->mime_id, $mimeid . '.') === 0) {
+            continue 2;
+          }
+        }
+
         if ($part_body = rcmail_compose_part_body($part, $isHtml)) {
           $body .= ($body ? ($isHtml ? '<br/>' : "\n") : '') . $part_body;
         }
@@ -1021,7 +1038,9 @@ function rcmail_write_compose_attachments(&$message, $bodyIsHtml)
       $loaded_attachments[$attachment['name'] . $attachment['mimetype']] = $attachment;
   }
 
-  $cid_map = $messages = array();
+  $cid_map  = array();
+  $messages = array();
+
   foreach ((array)$message->mime_parts as $pid => $part)
   {
     if ($part->disposition == 'attachment' || ($part->disposition == 'inline' && $bodyIsHtml) || $part->filename) {
@@ -1033,25 +1052,32 @@ function rcmail_write_compose_attachments(&$message, $bodyIsHtml)
       if ($part->ctype_primary == 'message' && $compose_mode == RCUBE_COMPOSE_REPLY) {
         continue;
       }
-      // skip inline images when forwarding
-      if ($part->content_id && $part->disposition == 'inline' && $compose_mode == RCUBE_COMPOSE_FORWARD) {
+      // skip inline images when forwarding in text mode
+      if ($part->content_id && $part->disposition == 'inline' && !$bodyIsHtml && $compose_mode == RCUBE_COMPOSE_FORWARD) {
         continue;
       }
 
-      $skip = false;
+      // skip message/rfc822 attachments on forwards (#1489214)
+      // Thunderbird when forwarding in inline mode displays such attachments
+      // and skips any attachments from inside of such part, this however
+      // skipped e.g. images used in HTML body or other attachments. So,
+      // better to skip .eml attachments but not their content (included files).
       if ($part->mimetype == 'message/rfc822') {
+        if ($compose_mode == RCUBE_COMPOSE_FORWARD) {
+          continue;
+        }
         $messages[] = $part->mime_id;
-      } else if ($messages) {
+      }
+      else if ($compose_mode != RCUBE_COMPOSE_FORWARD) {
         // skip attachments included in message/rfc822 attachment (#1486487)
         foreach ($messages as $mimeid)
-          if (strpos($part->mime_id, $mimeid.'.') === 0) {
-            $skip = true;
-            break;
+          if (strpos($part->mime_id, $mimeid . '.') === 0) {
+            continue 2;
           }
       }
 
-      if (!$skip && (($attachment = $loaded_attachments[rcmail_attachment_name($part) . $part->mimetype])
-          || ($attachment = rcmail_save_attachment($message, $pid)))) {
+      if (($attachment = $loaded_attachments[rcmail_attachment_name($part) . $part->mimetype])
+          || ($attachment = rcmail_save_attachment($message, $pid))) {
         $COMPOSE['attachments'][$attachment['id']] = $attachment;
         if ($bodyIsHtml && ($part->content_id || $part->content_location)) {
           $url = sprintf('%s&_id=%s&_action=display-attachment&_file=rcmfile%s',