From: Jeff King <peff@peff.net>
Date: Tue, 14 Jan 2020 21:25:48 GMT
Subject: Re: [PATCH 8/8] sparse-checkout: write escaped patterns in cone mode
Message-ID: <20200114212548.GD3949560@coredump.intra.peff.net>
In-Reply-To: <79b6e9a565fde766954d7cda84a835b9015af6cb.1579029963.git.gitgitgadget@gmail.com>

On Tue, Jan 14, 2020 at 07:26:02PM +0000, Derrick Stolee via GitGitGadget wrote:

> From: Derrick Stolee <dstolee@microsoft.com>
> 
> If a user somehow creates a directory with an asterisk (*) or backslash
> (\), then the "git sparse-checkout set" command will struggle to provide
> the correct pattern in the sparse-checkout file. When not in cone mode,
> the provided pattern is written directly into the sparse-checkout file.
> However, in cone mode we expect a list of paths to directories and then
> we convert those into patterns.
> 
> Even more specifically, the goal is to always allow the following from
> the root of a repo:
> 
>   git ls-tree --name-only -d HEAD | git sparse-checkout set --stdin
> 
> The ls-tree command provides directory names with an unescaped asterisk.
> It also quotes the directories that contain an escaped backslash. We
> must remove these quotes, then keep the escaped backslashes.

Do we need to document these rules somewhere? Naively I'd expect
"--stdin" to take in literal pathnames. But of course it can't represent
a path with a newline. So perhaps it makes sense to take quoted names by
default, and allow literal NUL-separated input with "-z" if anybody
wants it.

-Peff