Re: [PATCH 1/1] mingw: only test index entries for backslashes, not tree entries

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Jonathan,

On Fri, 3 Jan 2020, Jonathan Nieder wrote:

> Johannes Schindelin wrote:
>
> > As mentioned above, the idea is to prevent Git from attempting to create
> > files with illegal file name characters.
> [...]
> > On Thu, 26 Dec 2019, Jonathan Nieder wrote:
>
> >> Is there anything we can or should do to prevent people checking in
> >> new examples of paths with backslash in them (on all platforms)?
> >
> > As mentioned in my reply to Junio, I don't think that it would be wise to
> > even try to warn about backslashes in the file names. There are _so_ many
> > Git users out there, I am convinced that at least some of them have valid
> > use cases for file names with backslashes in them.
>
> Thanks for the quick answers.  It helps.
>
> I think allowing people to clone
> https://github.com/zephyrproject-rtos/civetweb but not to check out
> the problematic historic revision is a reasonable choice, especially
> since it's still possible to get the data from there using
>
> 	git checkout <rev> -- . ':!bad-paths'
>
> [...]
> > Or maybe you know of a code path in the `unpack_trees()` machinery that
> > does _not_ go through `add_index_entry()`? I would be very interested to
> > learn about such code paths.
>
> Every once in a while someone (e.g., in #git) has wanted "git checkout
> --skip-index <rev> -- <paths>", and that would be the natural way to
> implement such a thing.  But no one has done it yet. :)
>
> We'll just have to keep a watchful eye as people make new
> contributions.

Right.

As to my patch, in the meantime I wondered whether I should simply extend
`verify_path()` to take a `flags` parameter where I can specify whether
this is intended for checkout, and handle the backslashes _there_. That
would cover e.g. uses of `make_transient_cache_entry()`, too.

The only reason why I would want to introduce `flags` is that `git apply`
has this `--unsafe-paths` option where `verify_paths()` is called on the
file names in the diff, and I was unsure whether there are legitimate use
cases with diffs containing DOS-style paths (I suspect that there are
legitimate scenarios where this is desirable).

What do you think of that?

Ciao,
Dscho