add post-DEV_6 SQL from PR ome#1645

sql/psql/OMERO5.0DEV__6/OMERO4.4__0.sql

@@ -17,8 +17,7 @@
 --
 
 ---
---- OMERO5 development release upgrade from OMERO4.4__0 to OMERO5.0DEV__6
---- hopefully close to an eventual upgrade from OMERO4.4__0 to OMERO5.0BETA__0.
+--- OMERO5 development release upgrade from OMERO4.4__0 to OMERO5.0DEV__6.
 ---
 
 BEGIN;
@@ -525,6 +524,24 @@ CREATE TRIGGER _fs_log_delete
     AFTER DELETE ON originalfile
     FOR EACH ROW EXECUTE PROCEDURE _fs_log_delete();
 
+--
+-- Upgrade beyond OMERO5.0DEV__6. Break out into separate script once patch is bumped.
+--
+
+-- Prevent Directory entries in the originalfile table from having their mimetype changed.
+CREATE FUNCTION _fs_directory_mimetype() RETURNS "trigger" AS $$
+    BEGIN
+        IF OLD.mimetype = 'Directory' AND NEW.mimetype != 'Directory' THEN
+            RAISE EXCEPTION '%%', 'Directory('||OLD.id||')='||OLD.path||OLD.name||'/ must remain a Directory';
+        END IF;
+        RETURN NEW;
+    END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER _fs_directory_mimetype
+    BEFORE UPDATE ON originalfile
+    FOR EACH ROW EXECUTE PROCEDURE _fs_directory_mimetype();
+
 --
 -- FINISHED
 --