From: Jeff King <peff@peff.net>
Date: Tue, 01 Jun 2010 17:14:00 GMT
Subject: Re: Best way to apply textconv to a working tree file
Message-ID: <20100601171359.GD9702@sigill.intra.peff.net>
In-Reply-To: <vpqd3walot1.fsf@bauges.imag.fr>

On Tue, Jun 01, 2010 at 06:07:06PM +0200, Matthieu Moy wrote:

> After thinking about it, I think a mix of these solutions would be
> OK:
> 
> git cat-file --textconv <blob-sha1>            # Run textconv on blob

This wouldn't work. The textconv is defined by the diff driver, which is
associated with a pathname, not a blob. You don't have a pathname here
(and in fact the same blob could potentially even be represented by
different textconvs if it appeared in different contexts).

> git cat-file --textconv <tree-sha1>:<filename> # Run textconv on file
>                                                # (in object database)

This could work in theory, but will not be as easy to implement as you
hope. The code to parse <tree-ish>:<filename> will give you only a blob
sha1, and you will have to look up the tree manually (which you will
have to split at the ":" manually, remembering that it may be as complex
as "HEAD@{12:00 yesterday}:foo.c", then check the diff attr manually for
that filename.

It would be nice if there was some way in the get_sha1* functions to
save some context, like tree context and filename. This would be helpful
for something like "git show HEAD:foo.txt", which probably should be
respecting autocrlf and smudge/clean filters.

> git cat-file --textconv ./<filename>           # Run textconv on file
>                                                # (in worktree)

FWIW, I think this combination is the best of the possible syntaxes
outlined in the original mail.

-Peff