625ed92134
If we're not given any refspecs (either on the command line or via config) and we have no branch merge config, then we fetch the remote HEAD into our local FETCH_HEAD. In that case we do not send any ref-prefix option to the server at all, and we see the full advertisement. But this is sub-optimal. We only care about HEAD, so we can just ask for that, and ignore all of the other refs. The new test demonstrates a case where we see fewer refs (in this case only one less, but in theory we could be ignoring millions of them). This also removes the only case where we care about seeing some refs from the other side, but don't add anything to the ref_prefixes list. Cleaning this up means one less maintenance burden. Before this patch, any code which wanted to add to the list had to make sure the list was not empty, since an empty list meant "ask for everything". Now it really means "we are not interested in any refs". This should let us optimize a few more cases in subsequent patches. Note that we'll add "HEAD" to the list of prefixes, and later code for updating "refs/remotes/<remote>/HEAD" may likewise do so. In theory this could cause duplicates in the list, but in practice these can't both trigger. We hit our new case only if there are no refspecs, and the "<remote>/HEAD" feature is enabled only when we are fetching from a remote with configured refspecs. We could be defensive with a flag, but it didn't seem worth it to me (the absolute worse case is a useless redundant ref-prefix line sent to the server). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git - fast, scalable, distributed revision control system
Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.
Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.
See Documentation/gittutorial.adoc to get started, then see
Documentation/giteveryday.adoc for a useful minimum set of commands, and
Documentation/git-<commandname>.adoc for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with man gittutorial or git help tutorial, and the
documentation of each command with man git-<commandname> or git help <commandname>.
CVS users may also want to read Documentation/gitcvs-migration.adoc
(man gitcvs-migration or git help cvs-migration if git is
installed).
The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission and Documentation/CodingGuidelines).
Those wishing to help with error message, usage and informational message
string translations (localization l10) should see po/README.md
(a po file is a Portable Object file that holds the translations).
To subscribe to the list, send an email to git+subscribe@vger.kernel.org (see https://subspace.kernel.org/subscribing.html for details). The mailing list archives are available at https://lore.kernel.org/git/, https://marc.info/?l=git and other archival sites.
Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.
The maintainer frequently sends the "What's cooking" reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very first version. He described the tool as "the stupid content tracker" and the name as (depending on your mood):
- random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
- "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks