read-cache: optionally disallow HFS+ .git variants

The point of disallowing ".git" in the index is that we
would never want to accidentally overwrite files in the
repository directory. But this means we need to respect the
filesystem's idea of when two paths are equal. The prior
commit added a helper to make such a comparison for HFS+;
let's use it in verify_path.

We make this check optional for two reasons:

  1. It restricts the set of allowable filenames, which is
     unnecessary for people who are not on HFS+. In practice
     this probably doesn't matter, though, as the restricted
     names are rather obscure and almost certainly would
     never come up in practice.

  2. It has a minor performance penalty for every path we
     insert into the index.

This patch ties the check to the core.protectHFS config
option. Though this is expected to be most useful on OS X,
we allow it to be set everywhere, as HFS+ may be mounted on
other platforms. The variable does default to on for OS X,
though.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/environment.c b/environment.c
index 0a15349cfe..828b574a29 100644
--- a/environment.c
+++ b/environment.c
@@ -63,6 +63,11 @@ int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
 struct startup_info *startup_info;
 unsigned long pack_size_limit_cfg;
 
+#ifndef PROTECT_HFS_DEFAULT
+#define PROTECT_HFS_DEFAULT 0
+#endif
+int protect_hfs = PROTECT_HFS_DEFAULT;
+
 /*
  * The character that begins a commented line in user-editable file
  * that is subject to stripspace.