Re: [PATCH] Documentation/i18n.txt: clarify character encoding support

Am 15.06.2015 um 02:12 schrieb Junio C Hamano:

Karsten Blees [off-list ref] writes:

quoted

diff --git a/Documentation/i18n.txt b/Documentation/i18n.txt
index e9a1d5d..e5f6233 100644
--- a/Documentation/i18n.txt
+++ b/Documentation/i18n.txt

@@ -1,18 +1,28 @@
-At the core level, Git is character encoding agnostic.
-
- - The pathnames recorded in the index and in the tree objects
-   are treated as uninterpreted sequences of non-NUL bytes.
-   What readdir(2) returns are what are recorded and compared
-   with the data Git keeps track of, which in turn are expected
-   to be what lstat(2) and creat(2) accepts.  There is no such
-   thing as pathname encoding translation.
+Git is to some extent character encoding agnostic.

I do not think the removal of the text makes much sense here unless
you add the equivalent to the new text below.

quoted

  - The contents of the blob objects are uninterpreted sequences
    of bytes.  There is no encoding translation at the core
    level.
 
- - The commit log messages are uninterpreted sequences of non-NUL
-   bytes.
+ - Pathnames are encoded in UTF-8 normalization form C. This

That is true only on some systems like OSX (with HFS+) and Windows,
no?  BSDs in general and Linux do not do any such mangling IIRC.

Modern Unices don't need any such mangling because UTF-8 NFC should
be the default system encoding. I'm not sure for BSDs, but it has
been the default on all major Linux distros for more than 10 years.

I
am OK with mangling described as a notable oddball to warn users,
though; i.e. not as a norm as your new text suggests but as an
exception.

I would guess that non-UTF-8 Unices (or file systems) are the oddball
case, which is why I described them last. But I could be wrong.

quoted

+   platforms. If file system APIs don't use UTF-8 (which may be
+   file system specific), it is recommended to stick to pure
+   ASCII file names.

Hmph, who endorsed such a recommendation?  It is recommended to
stick to whatever naming scheme that would not cause troubles to
project participants.  If your participants all want to (and can)
use ISO-8859-1, we do not discourage them from doing so.

ISO-8859-x file names may be fine if you won't ever need to:
- use git-web, JGit, gitk, git-gui...
- exchange repos with "normal" (UTF-8) Unices, Mac and Windows systems
- publish your work on a git hosting service (and expect file and
  ref names to show up correctly in the web interface)
- store the repo on Unicode-based file systems (JFS, Joliet, UDF,
  exFat, NTFS, HFS, CIFS...)

These restrictions are not that obvious when you start a new git
project, and while converting file names after the fact is possible
(e.g. using the recodetree script we shipped with Git for Windows
1.7.10), it will destroy history.

Thus I think we should strongly discourage users from using anything
but UTF-8.