files: Record undetected inline images on upgrade

This will look through the database and find images which appear to be
inlined in thread entries, but are not recorded as inline. It will update
the %ticket_attachment table to reflect the inline disposition of the
images.

include/upgrader/streams/core/b26f29a6-1ee831c8.patch.sql

@@ -206,6 +206,21 @@ UPDATE `%TABLE_PREFIX%form_field` SET `flags` = `flags` |
    | IF(`edit_mask` & 16, CONV(10, 16, 10), 0)
    | IF(`edit_mask` & 32, CONV(40, 16, 10), 0);
 
+-- Detect inline images not recorded as inline
+CREATE TABLE `%TABLE_PREFIX%_unknown_inlines` AS
+  SELECT A2.`attach_id`
+  FROM `%TABLE_PREFIX%file` A1
+  JOIN `%TABLE_PREFIX%ticket_attachment` A2 ON (A1.id = A2.file_id)
+  JOIN `%TABLE_PREFIX%ticket_thread` A3 ON (A3.ticket_id = A2.ticket_id)
+  WHERE A1.`type` LIKE 'image/%' AND A2.inline = 0
+    AND A3.body LIKE CONCAT('%"cid:', A1.key, '"%');
+
+UPDATE `%TABLE_PREFIX%ticket_attachment` A1
+  JOIN %TABLE_PREFIX%_unknown_inlines A2 ON (A1.attach_id = A2.attach_id)
+  SET A1.inline = 1;
+
+DROP TABLE `%TABLE_PREFIX%_unknown_inlines`;
+
 -- Finished with patch
 UPDATE `%TABLE_PREFIX%config`
     SET `value` = '1ee831c854fe9f35115a3e672916bb91'