Several cases of copyright infringement

This repository publishes code copied from and/or based on copyrighted 3rd party code published under specific licenses; without fulfilling the terms defined in those licenses. Particularly, the original license comments in the original files were removed and replaced by a license claim of the infringing party. That's not acceptable. Also, it's just silly, as the original licenses permit to use/modify/republish or even sell the code without having to pay anything to the authors of the original code.

Examples

format.go contains verbatim copies of parts of code originaly published in strutil.go.
btree.go contains verbatim copies of parts of code originaly published in btree.go.
Many files found in the plan directory contain code clearly derived and/or parts sometimes verbatim copied from code originally published in plan.go.

In only minutes, I was able to found tens of similar additional copyright infringements. Also, this repository now has 100+ of forks and every single fork has the same copyright issue.

In essence, this project is an adaption/extension of the QL project for other SQL syntax and features, including alternative back-ends. (Which is, in sum, an amazing achievement - sincere congratulations.)

To the owners, maintainers of this repository: Please let me know your thoughts/plans/intentions related to this issue. Thanks.

@cznic

Thank you for your comment! TiDB is derived from the cznic/ql codebase, thank you again for the awesome job!

We'll add the ql-licence declaration in the files that contains your code. Is that OK? Please let us know :)
Just like this:

// Copyright 2015 The ql Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Copyright 2015 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

.....
@cznic