This is a fairly functional variation of Gitblit with one notable
exception:

    The security filters are not working properly.

This is a design flaw in Guice that I have reported upstream [1].  The
general idea is that Guice-Servlet filters are not properly wrapping the
ServletRequest. This has historically been a problem for Guice-Servlet
servlets but Google has fixed most of those issues.  Unfortunately, all
the same flaws reported against the servlet delegation also exist in
Guice-Servlet filter delegation. :(

[1]: https://code.google.com/p/google-guice/issues/detail?id=807

The Jetty 9.2 quick start mechanism provides almost an order of
magnitude improvement in start time [1].

[1] https://webtide.com/jetty-9-quick-start/

Plugins are stored in `${baseFolder}/plugins` and are loaded
during startup by the PluginManager.

A plugin defines it's metadata in META-INF/MANIFEST.MF:

    Plugin-Class: com.gitblit.plugins.cookbook.CookbookPlugin
    Plugin-Dependencies: foo, bar
    Plugin-Id: gitblit-plugin
    Plugin-Provider: John Doe
    Plugin-Version: 1.0

Plugins can define extension points that can be implemented
by other plugins and they can depend on other plugins:

    Plugin-Dependencies: foo, bar

During the load phase, a directed acyclic graph is built and the loading
order of the dependency chain is reversed using a topological sort;
parent followed by children. The parent plugin classloader is the
combined classloader of all parent plugins.

Change-Id: I738821fa2bff02a5dbe339a944cc7e3c4dd8e299

Change-Id: Ic7e204fb7ee2eb172f4c8424fc3d4b7e6c631ddd

Gitblit would greatly benefit from an integrated SSH server.  This would
complete the transport trifecta.

Change-Id: I6fb95abe65655fa74d47ea71522d8d9a1541450c

A basic issue tracker styled as a hybrid of GitHub and BitBucket issues.
You may attach commits to an existing ticket or you can push a single
commit to create a *proposal* ticket.

Tickets keep track of patchsets (one or more commits) and allow patchset
rewriting (rebase, amend, squash) by detecing the non-fast-forward
update and assigning a new patchset number to the new commits.

Ticket tracker
--------------

The ticket tracker stores tickets as an append-only journal of changes.
The journals are deserialized and a ticket is built by applying the
journal entries.  Tickets are indexed using Apache Lucene and all
queries and searches are executed against this Lucene index.

There is one trade-off to this persistence design: user attributions are
non-relational.

What does that mean?  Each journal entry stores the username of the
author.  If the username changes in the user service, the journal entry
will not reflect that change because the values are hard-coded.

Here are a few reasons/justifications for this design choice:

1. commit identifications (author, committer, tagger) are non-relational
2. maintains the KISS principle
3. your favorite text editor can still be your administration tool

Persistence Choices
-------------------

**FileTicketService**: stores journals on the filesystem
**BranchTicketService**: stores journals on an orphan branch
**RedisTicketService**: stores journals in a Redis key-value datastore

It should be relatively straight-forward to develop other backends
(MongoDB, etc) as long as the journal design is preserved.

Pushing Commits
---------------

Each push to a ticket is identified as a patchset revision.  A patchset
revision may add commits to the patchset (fast-forward) OR a patchset
revision may rewrite history (rebase, squash, rebase+squash, or amend).
Patchset authors should not be afraid to polish, revise, and rewrite
their code before merging into the proposed branch.

Gitblit will create one ref for each patchset.  These refs are updated
for fast-forward pushes or created for rewrites.  They are formatted as
`refs/tickets/{shard}/{id}/{patchset}`.  The *shard*  is the last two
digits of the id.  If the id < 10, prefix a 0.  The *shard* is always
two digits long.  The shard's purpose is to ensure Gitblit doesn't
exceed any filesystem directory limits for file creation.

**Creating a Proposal Ticket**

You may create a new change proposal ticket just by pushing a **single
commit** to `refs/for/{branch}` where branch is the proposed integration
branch OR `refs/for/new` or `refs/for/default` which both will use the
default repository branch.

    git push origin HEAD:refs/for/new

**Updating a Patchset**

The safe way to update an existing patchset is to push to the patchset
ref.

    git push origin HEAD:refs/heads/ticket/{id}

This ensures you do not accidentally create a new patchset in the event
that the patchset was updated after you last pulled.

The not-so-safe way to update an existing patchset is to push using the
magic ref.

    git push origin HEAD:refs/for/{id}

This push ref will update an exisitng patchset OR create a new patchset
if the update is non-fast-forward.

**Rebasing, Squashing, Amending**

Gitblit makes rebasing, squashing, and amending patchsets easy.

Normally, pushing a non-fast-forward update would require rewind (RW+)
repository permissions.  Gitblit provides a magic ref which will allow
ticket participants to rewrite a ticket patchset as long as the ticket
is open.

    git push origin HEAD:refs/for/{id}

Pushing changes to this ref allows the patchset authors to rebase,
squash, or amend the patchset commits without requiring client-side use
of the *--force* flag on push AND without requiring RW+ permission to
the repository.  Since each patchset is tracked with a ref it is easy to
recover from accidental non-fast-forward updates.

Features
--------

- Ticket tracker with status changes and responsible assignments
- Patchset revision scoring mechanism
- Update/Rewrite patchset handling
- Close-on-push detection
- Server-side Merge button for simple merges
- Comments with Markdown syntax support
- Rich mail notifications
- Voting
- Mentions
- Watch lists
- Querying
- Searches
- Partial miletones support
- Multiple backend options