238191ecfc
When we have an "onbranch" condition we need to ask the reference
database whether HEAD currently points at the configured branch. This
unfortunately creates a chicken-and-egg problem:
- The reference database needs to read the configuration so that it
can configure itself.
- The configuration needs to construct a reference database to fully
parse all of its conditionals.
The way we handle this is by simply excluding "onbranch" conditionals
when we haven't yet configured the reference database.
The mechanism for this is broken though: to verify whether or not we
have configured the reference database we check whether its format is
set to `REF_STORAGE_UNKNOWN` in `include_by_branch()`. But typically,
the format _is_ already known at that time because we set it up during
repository discovery in "setup.c".
The consequence is that we have recursion:
1. We call `get_main_ref_store()`.
2. We don't yet have a reference store, so we call `ref_store_init()`.
3. We parse the configuration required for the reference store.
4. We eventually end up in `include_by_branch()`.
5. We have already configured the reference storage format, so we end
up calling `get_main_ref_store()` again.
We still haven't finished (1) though, so `get_main_ref_store()` will now
call `ref_store_init()` a second time. The end result is that we have
constructed the same reference store twice.
Of course, as both reference stores would be assigned to `refs_private`,
we leak one of those two instances. This never surfaced as an actual
leak though because the pointer is kept alive by the "chdir_notify"
subsystem.
For now, we can fix the issue by explicitly unsetting the reference
storage format before constructing it. This makes the mentioned check
trigger as expected, and consequently we won't end up constructing a
second reference database at all. Ultimately, this means that we
consistently stop evaluating "onbranch" conditions when constructing the
main reference database.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
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).
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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