Fix where with sequelize.fn

lib/dialects/abstract/query-generator.js

@@ -1656,7 +1656,7 @@ module.exports = (function() {
         }
       }
 
-      if (value && value._isSequelizeMethod) {
+      if (value && value._isSequelizeMethod && !(key !== undefined && value instanceof Utils.fn)) {
         return this.handleSequelizeMethod(value);
       }
 

test/unit/sql/where.test.js

@@ -463,5 +463,13 @@ suite(Support.getTestDialectTeaser('SQL'), function() {
         });
       });
     }
+
+    suite('fn', function () {
+      test('{name: this.sequelize.fn(\'LOWER\', \'DERP\')}', function () {
+        expectsql(sql.whereQuery({name: this.sequelize.fn('LOWER', 'DERP')}), {
+          default: "WHERE [name] = LOWER('DERP')"
+        });
+      });
+    });
   });
 });