[Announce] libgit2 v0.17.0

Hello everyone,

A new libgit2 release is here. This one is huge (most new features to date). Check out the diff API. It's shiny.

We're nearing the 1.0.0 milestone, and things are moving much faster now. Stay tuned for more features and more projects using the library.

The release has been tagged at:

 https://github.com/libgit2/libgit2/tree/v0.17.0

A dist package can be found at:

 https://github.com/downloads/libgit2/libgit2/libgit2-0.17.0.tar.gz

Updated documentation can be found at:

 http://libgit2.github.com/libgit2/

The full change log follows after the message.

Cheers, Vicent

=======================

libgit2 v0.17.0 "Lord of Diffstruction"

Welcome to yet another libgit2 release, this one being the biggest we've shipped so far. Highlights on this release include diff, branches, notes and submodules support. The new diff API is shiny and powerful. Check it out.

Apologies, one more time, to all the early adopters for the breaking API changes. We've been iterating on the error handling for the library until we reached its current state, which we believe it's significantly more usable both for normal users and for developers of bindings to other languages. Also, we've renamed a few legacy calls to ensure that the whole external API uses a consistent naming scheme.

As always, check the API docs for the full list of new API calls and backwards-incompatible changes.

	http://libgit2.github.com/libgit2/

Changelog of new features follows:

Attributes:
	- Added function macros to check attribute values instead of having
	to manually compare them
	- Added support for choosing the attribute loading order (workdir files
	vs index) and to skip the systems' default `.gitattributes`
	- Fixed issues when fetching attribute data on bare repositories

Blob:
	- Added support for creating blobs from any file on disk (not
	restricted to the repository's working directory)
	- Aded support for smudge filters when writing blobs to the ODB
		- So far only CRLF normalization is available

Branches:
	- Added a high-level branch API:
		- git_branch_create
		- git_branch_delete
		- git_branch_list
		- git_branch_move

Commit:
	- Commit messages are now filtered to match Git rules (stripping
	comments and adding proper whitespacing rules)

Config:
	- Added support for setting and getting multivars
	- Added `git_config_get_mapped` to map the value of a config
	variable based on its defaults

Diff:
	- Added full diff API:
		- tree to tree
		- index to tree
		- workdir to index
		- workdir to tree
		- blob to blob

	- Added helper functions to print the diffs as valid patchfiles

Error handling:
	- New design for the error handling API, taking into consideration
	the requirements of dynamic languages

Indexer:
	- Added streaming packfile indexer

Merge:
	- Added support for finding the merge base between two commits

Notes:
	- Full git-notes support:
		- git_note_read
		- git_note_message/git_note_oid
		- git_note_create
		- git_note_remove
		- git_note_free
		- git_note_foreach

References:
	- Added `git_reference_name_to_oid` helper to resolve
	a reference to its final OID

	- Added `git_reference_cmp` to compare two references with
	a stable order

Remotes:
	- Added support for writing and saving remotes
		- `git_remote_add`
		- `git_remote_save`
		- Setters for all the attributes of a remote
	- Switched remote download to the new streaming packfile indexer
	- Fixed fetch on HTTP and Git under Windows
	- Added `git_remote_supported_url` helper to check if a protocol
	can be accessed by the library
	- Added `git_remote_list`

Repository:
	- Made `git_repository_open` smarter when finding the `.git` folder.
	- Added `git_repository_open_ext` with extra options when
	opening a repository

Revwalk:
	- Added support for pushing/hiding several references through a glob
	- Added helper to push/hide the current HEAD to the walker
	- Added helper to push/hide a single reference to the walker

Status:
	- Greatly improved Status implementation using the new `diff` code
	as a backend

Submodules:
	- Added a partial submodules API to get information about a
	submodule and list all the submodules in a repository
		- git_submodule_foreach
		- git_submodule_lookup

Tag:
	- Added `git_tag_peel` helper to peel a tag to its pointed object
	- Tag messages are now filtered to match Git rules (stripping comments
	and adding proper whitespacing rules)

Tree:
	- Killed the old `git_tree_diff` API, which is replaced by the
	new diff code.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

Vicent Marti <vicent@github.com> writes:

This is cool. I've wanted this for a while. How do you ensure that the operation of libgit2 matches that of git proper? Is there any plan to slowly convert git commands over to a libgit2 implementation?

                             -Dave

<dag@cray.com> writes:

There is no "plan" in the "concrete timeline and implementation strategy" sense, but it is what any sane person would hope is a good longer-term direction.

But it is also a bit of a chicken and an egg problem.

I am hoping that the library would become solid enough to allow us to start attempting such an experiment some day, but at the same time, I know that that "some day" is not in a very near future, after having seen at $DAYJOB that a certain internal tool linked with a version of libgit2 breaking user's trees from time to time, bugs against the internal tool getting filed and then some of them getting fixed at libgit2 level, either by upstreaming fix or by updating to newer snapshot of libgit2.

On Wed, May 23, 2012 at 6:51 PM, Junio C Hamano <gitster@pobox.com> wrote:

If you're building internal tools with libgit2 and encountering issues, maybe somebody from $DAYJOB could spend some of his 20% time in throwing us a hand pushing the library forward. That way $DAYJOB and the whole community would benefit.

Love, Vicent