On python2 the following error is raised:
`LookupError: unknown encoding: unicode`
Seems like `unicode` is a correct encoding in Python 3 but not 2.
Fix:
1. Change encoding to `utf-8`
2. Pass output path string instead of opening file and passing
opened file object. Python2 and 3 might need different file
modes, passing just path lets ElementTree select appropriate
file mode.
Fixes: f00e90923c ('tools: Use ElementTree to write XML in generate-docs-nm-settings-docs-gir.py')
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/1249
Instead of manually writting XML line by line.
Quoting is automatic.
Makes it much easier to modify. (just add new elements)
Generated XML not indented at the moment.
* Create main() function and put its execution under
__name__ == '__main__' guard.
* Only one module import per line
* Use required=True to check if necessary arguments have
been passed.
* Remove usage() as ArgumentParser handles that already
The gtk-doc text that the tool receives is not XML, it's a plain text.
When setting the plain text as XML attribute, we need to properly escape
it. The previous XML escape code was naive, and didn't cover for a
plain ampersand.
(cherry picked from commit 1641cc1d03)
