Re: [PATCH/RFC v2] Document format of basic Git objects

From: Jeff King <peff@peff.net>
Date: Feb 20, 2012, 16:11 UTC
Message-ID: <20120220161101.GA27105@sigill.intra.peff.net>
In-Reply-To: <CACsJy8CEeZPf55idLB9NE-rf--ySmZh_9gkMc_zo0VmiVftMUg@mail.gmail.com>

On Mon, Feb 20, 2012 at 08:55:28PM +0700, Nguyen Thai Ngoc Duy wrote:

Show 7 quoted lines

> > Author-ident is typically utf-8 already, so you cannot assume "ASCII".
> 
> I wonder if anyone puts non utf-8 strings in there, or could we
> enforce utf-8 (i.e. validate and reject non utf-8 strings) and accept
> encoded word syntax (rfc 2047) with the help of the new
> $GIT_IDENT_ENCODING variable. The "accept ..." part can wait until
> someone is hit by "utf-8 only" check and steps up.

I was just having a similar discussion with libgit2 folks, who were wondering if there would ever be non-utf8 in there. When we call "reencode_commit_message", it looks like we do the whole object. In other words, your author name _must_ match any encoding you specify in the "encoding" header.

I.e., if you do:

  # latin1 é
  e=`printf '\xe9'`

  export GIT_AUTHOR_NAME="P${e}ff King"
  git init
  git config i18n.commitencoding iso8859-1
  touch foo && git add foo &&
  git commit --allow-empty -m "more latin1 ${e}ncoding"

both the name and the message should show fine on your utf8 terminal if you do this:

  git config i18n.logoutputencoding utf8
  git show

And similarly, we do the right thing in format-patch, both with and without logoutputencoding set:

  $ git format-patch --root --stdout | grep -Ei "^(from|subject):"
  From: =?iso8859-1?q?P=E9ff=20King?= <peff@peff.net>
  Subject: [PATCH] =?iso8859-1?q?more=20latin1=20=E9ncoding?=

  $ git config i18n.logoutputencoding utf8
  $ git format-patch --root --stdout | grep -Ei "^(from|subject):"
  From: =?utf8?q?P=C3=A9ff=20King?= <peff@peff.net>
  Subject: [PATCH] =?utf8?q?more=20latin1=20=C3=A9ncoding?=

(where 0xc3a9 is the utf8 equivalent of latin1 0xe9).

So I have no idea if people are using it or not, but it is actually usable.

-Peff