Re: [PATCH] setup: avoid double slashes when looking for HEAD

> From: Jeff King <peff@peff.net>
> 
> Andrew Baumann reported that when called outside of any Git worktree,
> `git rev-parse --is-inside-work-tree` eventually tries to access
> `//HEAD`, i.e.  any `HEAD` file in the root directory, but with a double
> slash.
> 
> This double slash is not only unintentional, but is allowed by the POSIX
> standard to have a special meaning. And most notably on Windows, it
> does, where it refers to a UNC path of the form `//server/share/`.
> 
> As a consequence, afore-mentioned `rev-parse` call not only looks for
> the wrong thing, but it also causes serious delays, as Windows will try
> to access a server called `HEAD`.  Let's simply avoid the unintended
> double slash.
> 
> Signed-off-by: Jeff King <peff@peff.net>
> Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>