如何管理来自BSD许可项目的贡献者的版权声明

该LICENSE文件中包含以下BSD许可证：

Copyright (c) 2006-2016 SymPy Development Team

All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

  a. Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.
  b. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.
  c. Neither the name of SymPy nor the names of its contributors
     may be used to endorse or promote products derived from this software
     without specific prior written permission.


THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.

我们通过git（https://github.com/sympy/sympy）管理源存储库，因此每个作者都拥有他或她创建的补丁。然后AUTHORS，我们有一个文件，其中列出了所有贡献补丁的人员（当前大约450个左右）。通常，作者将存储库分叉到github上，并在git commits中添加补丁。

一位作者分叉了存储库，但将其名称LICENSE作为版权声明添加到文件本身中，如下所示（我更改了名称）：

Copyright (c) 2006-2015 SymPy Development Team,
              2015-2016 John Doe

All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

  a. Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.
  b. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.
  c. Neither the name of SymPy nor the names of its contributors
     may be used to endorse or promote products derived from this software
     without specific prior written permission.


THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.

作者开发了一个补丁，修复了一个错误。该修补程序包括仅触摸一个文件并从一行删除19个字符，然后在同一文件的另一行添加18个字符。还将针对此错误的5行测试添加到测试文件中。而已。

在法律上允许我们在什么条件下应用他的补丁（通过挑选他的提交，例如在git meta数据中保留日期和作者的名字+电子邮件）？

a）我们是否需要修改LICENSE文件以添加他的版权声明？

b）或者，如果我们保持最新AUTHORS文件并保留git存储库（它专门跟踪哪些提交是由哪些作者贡献的），那么我们是否仍符合BSD许可证。

我不喜欢的选项）是，如果所有450米左右的贡献者需要这一点，那么我们就需要基本上保持的内容AUTHORS的文件LICENSE的文件，与一起Copyright字和年。Git可以更好地保留年份（甚至几天和几分钟）以及每位作者修改哪些行以及如何修改。然后，我们有了一个LICENSE不变的简单文件，并将作者列表保留在其中AUTHORS（并且有一个脚本使其与git中的作者列表保持同步）。

您可以合并具有兼容许可证的任何代码。

就是说，除非要将新更改引入代码库中，否则除非获得新的代码在兼容许可下的特殊许可，否则您将面临很多困难。

特别是，除非代码明确声明新的贡献受兼容许可证的约束，否则默认的“保留所有权利”许可证适用于它。拉该代码将构成版权侵权。

也有可能新代码是根据与您兼容的许可证进行许可的（并且您需要维护该代码的许可证），但与许多用户不兼容。例如，如果您使用的是BSD 2子句，并且有人在BSD 3子句下许可了fork的贡献，则可以很容易地将其放入代码中。但是，由于BSD 3子句与GPL不兼容，这将使您的项目GPL不兼容。

如果您稍后决定（例如）从BSD更改为GPL，并且拉取请求分配了必要的权利，以将更改许可作为贡献者许可协议的一部分，则您可以从未同意的其他项目中提取代码CLA可能会让您头疼。

多数民众赞成在一般情况下...

对于许可证文件已更改的特定情况，我不知道。通过简单阅读许可证文件：

Copyright (c) 2006-2015 SymPy Development Team,  
              2015-2016 John Doe

All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

一个。重新分发源代码必须保留上述版权声明，
   此条件列表和以下免责声明。

该位似乎表明，如果您要进行这些更改，则还需要更改许可证文件。

不幸的是，您目前没有明确定义的CLA。幸运的是，此时您只有450个人要问。

如果存在BSD许可的源代码，并且有人分叉添加了其他补丁，则新回购中的此新源代码应包括原始回购中确切的BSD许可文件，并且新补丁应使用新许可（甚至是相同的许可证）。因此，分支在存储库中应具有一个或两个许可证。编辑原始许可证是不可接受的，因为这违反了BSD许可证条款。

现在，如果原始存储库要从分叉中挑选补丁，则必须将分叉的新许可证副本添加到原始存储库中。最终，两个存储库将拥有每个许可证，一个许可证涵盖每组补丁。

SymPy还应该要求贡献者放弃对SymPy项目的版权。让贡献者在提交时保留其版权对各个补丁的潜在潜在问题。需要明确的贡献者协议才能清楚发生了什么。