Implement LfsProtocolServlet handling the "Git LFS v1 Batch API"
protocol [1]. Add a simple file system based LFS content store and the
debug-lfs-store command to simplify testing.

Introduce a LargeFileRepository interface to enable additional storage
implementation while reusing the same protocol implementation.

At the client side we have to configure the lfs.url, specify that
we use the batch API and we don't use authentication:

  [lfs]
	  url = http://host:port/lfs
	  batch = true
  [lfs "http://host:port/lfs"]
	  access = none

the git-lfs client appends the "objects/batch" to the lfs.url.

Hard code an Authorization header in the FileLfsRepository.getAction
because then git-lfs client will skip asking for credentials. It will
just forward the Authorization header from the response to the
download/upload request.

The FileLfsServlet supports file content storage for "Large File
Storage" (LFS) server as defined by the Github LFS API [2].

- upload and download of large files is probably network bound hence use
  an asynchronous servlet for good scalability
- simple object storage in file system with 2 level fan-out
- use LockFile to protect writing large objects against multiple
  concurrent uploads of the same object
- to prevent corrupt uploads the uploaded file is rejected if its hash
  doesn't match id given in URL

The debug-lfs-store command is used to run the LfsProtocolServlet and,
optionally, the FileLfsServlet which makes it easier to setup a
local test server.

[1]
https://github.com/github/git-lfs/blob/master/docs/api/http-v1-batch.md
[2] https://github.com/github/git-lfs/tree/master/docs/api

Bug: 472961
Change-Id: I7378da5575159d2195138d799704880c5c82d5f3
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Signed-off-by: Sasa Zivkov <sasa.zivkov@sap.com>

The Large File Storage extension specified by GitHub [1] uses SHA-256 to
compute the ID of large files stored by the extension. Hence implement a
SHA-256 abstraction similar to the SHA-1 abstraction used by JGit.

[1] https://git-lfs.github.com/

Bug: 470333
Change-Id: I3a95954543c8570d73929e55f4a884b55dbf1b7a
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

If the specified ref can't be resolved we should throw a
RefNotFoundException instead of an NPE.

Bug: 455005
Change-Id: I6ec9bf1c0f330eea5eb8277268f62663bdf58f66
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: I8ced7098da5b345fd9af2fdfafd1ef6a44ccee0d

This breaks all existing callers once. Applications are not supposed
to build against the internal storage API unless they can accept API
churn and make necessary updates as versions change.

Change-Id: I2ab1327c202ef2003565e1b0770a583970e432e9

- Translate internal exceptions to corresponding API exception
- Do not catch GitAPI exceptions internally to an internal
exception. Just pass them to caller
- Mention thrown exceptions in javadoc

Change-Id: I9044cf86d2b0bcc8b63b7cc016e1bf0055a62053
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

All commands should throw a GitAPIException so new exceptions can be
added without breaking the builds of old code, i.e. anyone that calls
a Git API should catch GitAPIException and not just the currently known
exceptions.

Now the only checked exceptions on Git API calls are GitException and
subclasses of it. New checked exceptions that are subclasses of
GitException may be added without breaking the API.

Javadoc for GitAPIException is declared on GitCommand and
inherited to subclasses. JGitInternalException is not explicitly
documented anymore.

Unfortunately this change itself breaks the API. The intention is
that it shall be possible to add new checked subclasses of
GitAPIException without breaking the API.

Bug: 366914
EGit-Change-Id: I50380f13fc82c22d0036f47c7859cc3a77e767c5
Change-Id: I50380f13fc82c22d0036f47c7859cc3a77e767c5
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: I763590a45d75f00a09097ab6f89581a3bbd3c797

ReflogCommand command was throwing an incorrect exception type
when an IOException was wrapped and rethrown from the underlying
ReflogReader.  The IOException cause is now provided to the thrown
exception as well.

Change-Id: I9f1842c2d414d3e9c658843f9b448bc18891748e

This mirrors the default command-line behavior.

Change-Id: I4f819410fa6df3064c560beb3184b61fd7bb1f15
Signed-off-by: Kevin Sawicki <kevin@github.com>

Adds a git-reflog command and associated tests.

Bug: 347859
Change-Id: Iba146ac842cc9ca0be43d3381b4082c9e92bf56f
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

The strings are externalized into the root resource bundles.
The resource bundles are stored under the new "resources" source
folder to get proper maven build.

Strings from tests are, in general, not externalized. Only in
cases where it was necessary to make the test pass the strings
were externalized. This was typically necessary in cases where
e.getMessage() was used in assert and the exception message was
slightly changed due to reuse of the externalized strings.

Change-Id: Ic0f29c80b9a54fcec8320d8539a3e112852a1f7b
Signed-off-by: Sasa Zivkov <sasa.zivkov@sap.com>

Per CQ 3448 this is the initial contribution of the JGit project
to eclipse.org.  It is derived from the historical JGit repository
at commit 3a2dd9921c.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>