Re: GB18030-2022 Support in PostgreSQL

>>
>> 3. Skip patch 2, directly go to patch 3. So that, patch 3 will include changes introduced by both 2005 and 2022. This way makes minimum changes to map files.
>
> #3 is what I had in mind to begin with unless we found some reason not
> to. Minimizing churn is a lucky side effect that reinforces that
> choice.
>

Cool, then I will take option 3.

> Before getting to that, I thought I'd bring this up to the community:
>
>
> The previous XML file didn't contain a copyright notice -- does anyone
> want to make a case for not checking unicode-org's source file into
> our tree because of this? The 2022 update changes it to
>
>

Thanks for pointing out the unicode license issue, I really didn’t notice about that.

I did some quick research. As we generate mapping files from the ucm files, and the map files are built into the final executable binaries, we are redistributing Unicode-derived data, so we should still include the Unicode license. Thus, not checking in the ucm won’t waive the license problem.

We can just added a license file, say named unicode_license.txt with proper content under the same folder of the ucm file. I guess that would address the license problem.

This following the ChatGTP generated content of the license file:

```
Portions of this product include data from the Unicode Character Database
and other Unicode® data files.

Copyright © 1991–2025 Unicode, Inc.
All rights reserved.

Permission is hereby granted, free of charge, to any person obtaining a copy
of the Unicode data files and any associated documentation (the "Data Files")
or Unicode software and any associated documentation (the "Software") to deal
in the Data Files or Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, and/or sell copies
of the Data Files or Software, and to permit persons to whom the Data Files or
Software are furnished to do so, provided that either:

(a) this copyright and permission notice appear with all copies of the Data
Files or Software, or

(b) this copyright and permission notice appear in associated documentation.

THE DATA FILES AND SOFTWARE ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD
PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN
THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL
DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THE DATA FILES OR
SOFTWARE.

Unicode and the Unicode logo are trademarks of Unicode, Inc. in the United
States and other countries. All third party trademarks referenced herein are
the property of their respective owners.
```

Regards,

Chao Li (Evan)
--------------------
HighGo Software Co., Ltd.
https://www.highgo.com/