Merge branch 'subparts' into 'master'

Some (rare) mails are not properly showing their attachments (not
Apple kind ones), as explained in MER#1574.

This is due to the fact that the routine that looks for attachments
works on one level only of mail subpart. The proposed MR adds a
recursive call to look for an attachment on any possible sub-level.

An example of non-working email is attached to the MER bug. This MR
corrects the behaviour for this mail.

See merge request !3

qmf/src/libraries/qmfclient/qmailmessage.cpp

@@ -1159,6 +1159,9 @@ namespace findAttachments
             if (container.multipartType() == QMailMessagePart::MultipartMixed) {
                 inMultipartMixed(container, found, hasAttachments);
             }
+            if (container.multipartType() == QMailMessagePart::MultipartAlternative) {
+                inMultipartMixed(container, found, hasAttachments);
+            }
             if (container.multipartType() == QMailMessagePart::MultipartSigned) {
                 inMultipartSigned(container, found, hasAttachments);
             }
@@ -1206,6 +1209,10 @@ namespace findAttachments
                 case QMailMessagePart::MultipartNone:
                     inMultipartNone(part, found, hasAttachments);
                     break;
+                case QMailMessagePart::MultipartMixed:
+                case QMailMessagePart::MultipartAlternative:
+                    inMultipartMixed(part, found, hasAttachments);
+                    break;
                 default:
                     break;
                 }