Add an option not to use link(src, dest) && unlink(src) when that is unreliable

It seems that accessing NTFS partitions with ufsd (at least on my EeePC)
has an unnerving bug: if you link() a file and unlink() it right away,
the target of the link() will have the correct size, but consist of NULs.

It seems as if the calls are simply not serialized correctly, as single-stepping
through the function move_temp_to_file() works flawlessly.

As ufsd is "Commertial software" (sic!), I cannot fix it, and have to work
around it in Git.

At the same time, it seems that this fixes msysGit issues 222 and 229 to
assume that Windows cannot handle link() && unlink().

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/cache.h b/cache.h
index ab1294d6fb..ff9e145be0 100644
--- a/cache.h
+++ b/cache.h
@@ -554,6 +554,8 @@ extern enum branch_track git_branch_track;
 extern enum rebase_setup_type autorebase;
 extern enum push_default_type push_default;
 
+extern int unreliable_hardlinks;
+
 #define GIT_REPO_VERSION 0
 extern int repository_format_version;
 extern int check_repository_format(void);