In get_active_slot(), we return a CURL handle that may have been used
before (reusing them is good because it lets curl reuse the same
connection across many requests). We set a few curl options back to
defaults that may have been modified by previous requests.
We reset POSTFIELDS to NULL, but do not reset POSTFIELDSIZE (which
defaults to "-1"). This usually doesn't matter because most POSTs will
set both fields together anyway. But there is one exception: when
handling a large request in remote-curl's post_rpc(), we don't set
_either_, and instead set a READFUNCTION to stream data into libcurl.
This can interact weirdly with a stale POSTFIELDSIZE setting, because
curl will assume it should read only some set number of bytes from our
READFUNCTION. However, it has worked in practice because we also
manually set a "Transfer-Encoding: chunked" header, which libcurl uses
as a clue to set the POSTFIELDSIZE to -1 itself.
So everything works, but we're better off resetting the size manually
for a few reasons:
- there was a regression in curl 8.7.0 where the chunked header
detection didn't kick in, causing any large HTTP requests made by
Git to fail. This has since been fixed (but not yet released). In
the issue, curl folks recommended setting it explicitly to -1:
https://github.com/curl/curl/issues/13229#issuecomment-2029826058
and it indeed works around the regression. So even though it won't
be strictly necessary after the fix there, this will help folks who
end up using the affected libcurl versions.
- it's consistent with what a new curl handle would look like. Since
get_active_slot() may or may not return a used handle, this reduces
the possibility of heisenbugs that only appear with certain request
patterns.
Note that the recommendation in the curl issue is to actually drop the
manual Transfer-Encoding header. Modern libcurl will add the header
itself when streaming from a READFUNCTION. However, that code wasn't
added until 802aa5ae2 (HTTP: use chunked Transfer-Encoding for HTTP_POST
if size unknown, 2019-07-22), which is in curl 7.66.0. We claim to
support back to 7.19.5, so those older versions still need the manual
header.
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.txt to get started, then see
Documentation/giteveryday.txt for a useful minimum set of commands, and
Documentation/git-<commandname>.txt 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.txt
(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