When calling gitfo_exists() on a symbolic link, sometimes we need to
simply check whether the link exists and sometimes we need to check
whether the file pointed to by the symlink exists.

Introduce a new function gitfo_shallow_exists that only checks if the
link exists and revert gitfo_exists to the original functionality of
checking whether the file pointed to by the link exists.

This reverts commit df1c98ab6d6171ed63729195bd190b54b67fe530.

As 8a27b6b reverts the exposition of struct stat to the external API, we
do not need - indeed, do not want - struct stat to be in the outer
include layer.

00582bc introduced a change that required the caller of
git_blob_create_fromfile() to pass a struct stat with the stat
information for the file. Several developers pointed out that this would
make life hard for the bindings developers as struct stat isn't widely
supported by other languages.

Make git_blob_create_fromfile() stat the path itself, eliminating the
need for the file to be stat'ed by the caller. This makes
index_init_entry() more costly as the file will be stat'ed twice but
makes life easier for everyone else.

00582bcb introduced a change to git_blob_create_fromfile() that required
the caller to pass a stat struct. This means that we need to include
stat.h higher in the hierarchy of includes.

The entry mode flags for an entry created from a path name were not
correctly written if the entry was a symlink. The st_mode of a statted
symlink is 0120777, however git requires the mode to read 0120000,
because it does not care about permissions of symlinks.

Introduce index_create_mode() that correctly writes the mode flags in
the form expected by git.

gitfo_exists() used to error out if the given file was a symbolic link,
due to access() returning an error code. This is not expected behaviour,
as gitfo_exists() should only check whether the file itself exists, not
its link target if it is a symbolic link.

Fix this by calling gitfo_lstat() instead, which is just a wrapper for
lstat().

Also fix the same error in index_init_entry().

In order to be able to write symlinks with git_blob_create_fromfile(),
we need to check whether the file to be written is a symbolic link or
not. Since the calling function of git_blob_create_fromfile() is likely to have
stated the file before calling, we make it pass the stat.

The reason for this is that writing symbolic link blobs is significantly
different from writing ordinary files - we do not want to open the link
destination but instead want to write the link itself, regardless of
whether it exists or not.

Previously, index_init_entry() used to error out if the file to be added
was a symlink that pointed to a nonexistent file. Fix this behaviour to
add the file regardless of whether it exists. This mimics git.git's
behaviour.

This time for good.

This commit uploaded an old broken test. Oops!

Tree: Added a function that returns the type of a tree entry.

Search objects of different types given OID prefix

Better name for git_oid_match

Fix build errors on MSVC

[Tree | Index] API uniformisation

reference_rename: respect all references v2

Cleanup the thread-utils file. Do not define TLS if libgit2 is not
threadsafe.

[Discovery path] Fix and tests

As suggested by carlosmn, git_oid_ncmp would probably
be a better name than git_oid_match, for it does the same
as git_oid_cmp but only up to a certain amount of hex digits.

given an OID prefix.

Repository: A little fix in error code. GIT_ENOTFOUND is returned when a gitfile is malformed and GIT_ENOTAREPO when the pointed dir is not a repo.
Fixed tests so that it check the right error code.

The filebuf was not being properly written after a flush. This should
cut it now.

Fixes #228

Feature Added: Search an unmerged entry by path (git_index_get_unmerged
renamed to git_index_get_unmerged_bypath) or by index (git_index_get_unmerged_byindex).

the error returned by the subsystem; clarify error message.

Fix tiny typo.

Signed-off-by: schu <schu-github@schulog.org>

Add a new function reference_available() to check if a reference name
actually is free and can be used.

Signed-off-by: schu <schu-github@schulog.org>

Signed-off-by: schu <schu-github@schulog.org>

Unfortunately, the across_fs flag can't be tested automaticly, as we can't
create a temporary new filesystem.

It used to discard the last directory if the path didn't have a trailing slash.

Now the ceiling_dirs are compared with their symbolic free version (like base_path).
The ceiling dirs check is now performed after getting the parent directory.

Discovery path v2

Repository: Added the git_repository_discover function that finds by itself the git directory that manage a given directory path.

Repository: Splitted the repository destructor into a helper part (only free directories path) and the complete public destructor.