Re: [PATCH] diff: add support for reading files literally with --no-index

From: Jeff King <peff@peff.net>
Date: Dec 20, 2018, 17:17 UTC
Message-ID: <20181220171725.GB6684@sigill.intra.peff.net>
In-Reply-To: <CACsJy8CScTBbYJt_LLp-rBdmJubEQOZqkPQeszzax9YpbCPUkg@mail.gmail.com>

On Thu, Dec 20, 2018 at 06:06:11PM +0100, Duy Nguyen wrote:

Show 13 quoted lines

> On Thu, Dec 20, 2018 at 1:26 AM brian m. carlson
> <sandals@crustytoothpaste.net> wrote:
> > @@ -5159,6 +5159,8 @@ int diff_opt_parse(struct diff_options *options,
> >                 options->flags.funccontext = 1;
> >         else if (!strcmp(arg, "--no-function-context"))
> >                 options->flags.funccontext = 0;
> > +       else if (!strcmp(arg, "--literally"))
> > +               options->flags.read_literally = 1;
> 
> You probably want to check in diff_setup_done() that if
> flags.read_literally is set but flags.no_index is not, then abandon
> ship and die() because --literally is not used with --no-index. Even
> when --no-index is implicit, flags.no_index should be set.

Yeah, good catch. "git diff --literally HEAD" should report an error.

Show 5 quoted lines

> I wonder if --follow-symlinks would be a good alternative for this
> (then if the final destination is unmmapable then we just read the
> file whole in memory without the user asking, so it will work with
> pipes). --follow-symlinks then could be made work with non-"no-index"
> case too. But --literally is also ok.

It's more than symlinks, though. Reading from a named pipe, we'd want to see the actual contents with --literally (and not "oops, I don't know how to represent a named pipe").

-Peff