GIT Updates: Detached HEAD, Packed Refs, Configuration, and More

your HEAD, you can go back to an existing branch with usual "git checkout $branch". Also you can start a new branch using "git checkout -b $newbranch" to start a new branch at that commit. - You can even pull from other repositories, make merges and commits while your HEAD is detached. Also you can use "git reset" to jump to arbitrary commit, while still keeping your HEAD detached. Remember that a detached state is volatile, i.e. it will be forgotten as soon as you move away from it with the checkout or reset command, unless a branch is created from it as mentioned above. It is also possible to rescue a lost detached state from the HEAD reflog. * Packed refs - Repositories with hundreds of tags have been paying large overhead, both in storage and in runtime, due to the traditional one-ref-per-file format. A new command, git-pack-refs, can be used to "pack" them in more efficient representation (you can let git-gc do this for you). - Clones and fetches over dumb transports are now aware of packed refs and can download from repositories that use them. * Configuration - configuration related to color setting are consolidated under color.* namespace (older diff.color.*, status.color.* are still supported). - 'git-repo-config' command is accessible as 'git-config' now. * Updated features - git-describe uses better criteria to pick a base ref. It used to pick the one with the newest timestamp, but now it picks the one that is topologically the closest (that is, among ancestors of commit C, the ref T that has the shortest output from "git-rev-list T..C" is chosen). - git-describe gives the number of commits since the base ref between the refname and the hash suffix. E.g. the commit one before v2.6.20-rc6 in the kernel repository is: v2.6.20-rc5-306-ga21b069 which tells you that its object name begins with a21b069, v2.6.20-rc5 is an ancestor of it (meaning, the commit contains everything -rc5 has), and there are 306 commits since v2.6.20-rc5. - git-describe with --abbrev=0 can be used to show only the name of the base ref. - git-blame learned a new option, --incremental, that tells it to output the blames as they are assigned. A sample script to use it is also included as contrib/blameview. - git-blame starts annotating from the working tree by default. * Less external dependency - We no longer require the "merge" program from the RCS suite. All 3-way file-level merges are now done internally. - The original implementation of git-merge-recursive which was in Python has been removed; we have a C implementation of it now. - git-shortlog is no longer a Perl script. It no longer requires output piped from git-log; it can accept revision parameters directly on the command line. * I18n - We have always encouraged the commit message to be encoded in UTF-8, but the users are allowed to use legacy encoding as appropriate for their projects. This will continue to be the case. However, a non UTF-8 commit encoding _must_ be explicitly set with i18n.commitencoding in the repository where a commit is made; otherwise git-commit-tree will complain if the log message does not look like a valid UTF-8

This update includes improvements to detached HEAD handling, introduction of packed refs for efficient storage, consolidated color configuration settings, and updates to features like git-describe and git-blame, as well as reduced external dependencies and improved internationalization support.