Re: Let's discuss about unicode compositions for filenames!

Hi, thanks for your review.

2012/2/9 Stefan Sperling <stsp_at_elego.de>:
> Open questions:

Here I try to answer these. Of course, I welcome everyone to answer.

>
>  - How can the client retrieve the configuration from the server?
>   This is related to server-dictated configuration, see
>   http://wiki.apache.org/subversion/ServerDictatedConfiguration
>   and http://subversion.tigris.org/issues/show_bug.cgi?id=1974
>   This issue would need to be solved first.

I read those two pages and I think it can be done with server-dictated
configuration.

>
>  - What happens if NFC/NFD is enabled in repository config, but the
>   repository contains non-normalised paths (i.e. did not go through
>   a dump/load cycle to normalise all paths)?

I think we will provide the check command for finding out:
- whether a repository contains the same filenames of different unicode
  normalized/unnormalized forms.
- all filenames in a repository are NFC.
- all filenames in a repository are NFD.

I think of an idea that we can change this config during loading cycle only,
that is, we can specify this config as an option to load command.
When load command finishes, the option value is saved in config.

However, administrators can cheat to change config file without loading,
as the config file is a plain text file. So we cannot enforce this config must
be set only by load command.

Therefore I think It should be administrators' responsibility to ensure this
config match a repository.

>
>  - How do we handle name collisions if both NFC and NFD forms exist
>   in a repository that sets the configuration to NCF or NFD?
>
>   Is an upgrade not supported in this case?

No, I think we don't support to change this config to NFC/NFD in this case.
Only unicode-normalization 'none' is allowed.

>
>   Or will duplicate paths need to be discarded from history?
>    How can the user filter the paths, and how can the user decide
>    which path is kept?

I think we don't support these. Maybe repository admin users
can remove one of duplicated filenames from history in repository
and try to load again, I wonder?

>
>    Or will duplicate paths be renamed throughout history?
>    How can the user rename the paths?

I think users can only normalize filenames during load command.
Users cannot rename filenames arbitrarily.

>
> Anything else? I cannot think of more questions but there might
> be more things to consider here.

-- 
)Hiroaki Nakamura) hnakamur_at_gmail.com