Workaround lost S/MIME parts

app/src/main/java/eu/faircode/email/Core.java

@@ -1187,6 +1187,24 @@ class Core {
             if (!message.content)
                 throw new IllegalArgumentException("Message body missing");
 
+            List<EntityAttachment> attachments = db.attachment().getAttachments(message.id);
+            for (EntityAttachment attachment : attachments)
+                if (EntityAttachment.SMIME_SIGNATURE.equals(attachment.encryption))
+                    for (EntityAttachment content : attachments)
+                        if (EntityAttachment.SMIME_CONTENT.equals(content.encryption)) {
+                            boolean afile = attachment.getFile(context).exists();
+                            boolean cfile = content.getFile(context).exists();
+                            if (!attachment.available || !afile || !content.available || !cfile) {
+                                Log.e("S/MIME vanished" +
+                                        " available=" + attachment.available + "/" + content.available +
+                                        " file=" + afile + "/" + cfile);
+                                db.attachment().setAvailable(attachment.id, false);
+                                db.attachment().setAvailable(content.id, false);
+                                db.attachment().setEncryption(attachment.id, null);
+                                db.attachment().setEncryption(content.id, null);
+                            }
+                        }
+
             imessage = MessageHelper.from(context, message, null, isession, false);
 
             try (OutputStream os = new BufferedOutputStream(new FileOutputStream(file))) {