[PATCH 0/2] handling alternates paths with colons

[Jeff King <peff@peff.net>]

On Sat, Dec 10, 2016 at 03:51:33AM -0500, Jeff King wrote:

> So here's the array of options, as I see it:
> 
>   1. Disable quarantine by default; only turn it on if you don't have
>      any of the funny corner cases.
> 
>   2. Introduce an extra single-item environment variable that gets
>      appended to the list of alternates, and side-steps quoting issues.
> 
>   3. Introduce a new variable that can hold an alternate list, and
>      either teach it reasonable quoting semantics, or give it a
>      less-common separator.
> 
>   4. Introduce quoting to the existing variable, but make the quoting
>      character sufficiently obscure that nobody cares about the lack of
>      backwards compatibility.

So I started on (4), but writing the user-facing documentation made me
throw up in my mouth a little. Fortunately that inspired me to come up
with a fifth option: introduce a quoting mechanism that needs a more
obscure signature to kick in, but once kicked-in, uses a less obscure
syntax.

So here are patches that do that. It kicks in only when the first
character of a path is a double-quote, and then expects the usual
C-style quoting. My reasoning is that we wouldn't want to sacrifice
'"' for ':', but it's probably OK if we only care about '"' at the very
beginning of a path. And it's consistent with many other parts of git
which allow optional quoting.

Thoughts?

  [1/2]: alternates: accept double-quoted paths
  [2/2]: tmp-objdir: quote paths we add to alternates

 Documentation/git.txt      |  6 ++++++
 sha1_file.c                | 47 +++++++++++++++++++++++++++++++++++-----------
 t/t5547-push-quarantine.sh | 19 +++++++++++++++++++
 t/t5615-alternate-env.sh   | 18 ++++++++++++++++++
 tmp-objdir.c               | 18 +++++++++++++++++-
 5 files changed, 96 insertions(+), 12 deletions(-)

-Peff