Re: [PATCH] Allow git-diff exit with codes similar to diff(1)

["Alex Riesen" <raa.lkml@gmail.com>]

On 3/14/07, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> > > So, big master to hom everybody bows, how to return the correct value
> > > when executing a pager? Because this _has_ to be done if we go that
> > > way.
> >
> > Why? If you execute the pager, nobody cares about the error value
> > anyway.
> >
> > I don't see why you would mix in a pager here. If you do
> >
> >       diff -u file1 file2 | less -S
> >
> > the return value of the pipe will not only generally be totally
> > uninteresting and never used, but it will be the return value of "less"
> > anyway. Which is what we'd get quite naturally.
>
> The thing is, most people do not realize that
>
>         git diff file1 file2
>
> _will_ execute a pager. As foreground process. And the return value is
> that of the pager.

In this example this is obviously (sometimes it is obscurely) interactive.
The return code is seldom expected.

More sneaky case could be this:

  git diff file1 file2 > tmp && do_something
  rm -f tmp

But we have isatty in setup_pager, so this works properly.