Implement "conversation lock" for issue comments (#5073)

models/migrations/v80.go

@@ -0,0 +1,18 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package migrations
+
+import "github.com/go-xorm/xorm"
+
+func addIsLockedToIssues(x *xorm.Engine) error {
+	// Issue see models/issue.go
+	type Issue struct {
+		ID       int64 `xorm:"pk autoincr"`
+		IsLocked bool  `xorm:"NOT NULL DEFAULT false"`
+	}
+
+	return x.Sync2(new(Issue))
+
+}