Re: [PATCH] setup.c: don't try to access '//HEAD' during repo discovery

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Nov 3, 2017, 12:36 UTC
Message-ID: <alpine.DEB.2.21.1.1711031334000.6482@virtualbox>
In-Reply-To: <20171103010645.25499-1-szeder.dev@gmail.com>

Hi Gábor,

On Fri, 3 Nov 2017, SZEDER Gábor wrote:

Show 11 quoted lines

> Commit ce9b8aab5 (setup_git_directory_1(): avoid changing global state,
> 2017-03-13) changed how the git directory is discovered, and as a side
> effect when the discovery reaches the root directory Git tries to
> access paths like '//HEAD' and '//objects'.  This interacts badly with
> Cygwin, which interprets it as a UNC file share, and so demand-loads a
> bunch of extra DLLs and attempts to resolve/contact the server named
> HEAD.  This obviously doesn't work too well, especially over a slow
> network link.
> 
> Special case the root directory in is_git_directory() to prevent
> accessing paths with leading double slashes.

I would rather not special-case the (Unix) root directory. The underlying problem, as Peff pointed out, is that an extra slash is appended if the directory. And as `is_git_directory()` is not marked as static, we must assume that there are other callers that may pass in directory paths ending in a slash already.

Ciao, Dscho