This reverts commit 14c7fa269e.
The core.repositoryFormatVersion field was introduced in ab9cb76f66
(Repository format version check., 2005-11-25), providing a welcome
bit of forward compatibility, thanks to some welcome analysis by
Martin Atukunda. The semantics are simple: a repository with
core.repositoryFormatVersion set to 0 should be comprehensible by all
Git implementations in active use; and Git implementations should
error out early instead of trying to act on Git repositories with
higher core.repositoryFormatVersion values representing new formats
that they do not understand.
A new repository format did not need to be defined until 00a09d57eb
(introduce "extensions" form of core.repositoryformatversion,
2015-06-23). This provided a finer-grained extension mechanism for
Git repositories. In a repository with core.repositoryFormatVersion
set to 1, Git implementations can act on "extensions.*" settings that
modify how a repository is interpreted. In repository format version
1, unrecognized extensions settings cause Git to error out.
What happens if a user sets an extension setting but forgets to
increase the repository format version to 1? The extension settings
were still recognized in that case; worse, unrecognized extensions
settings do *not* cause Git to error out. So combining repository
format version 0 with extensions settings produces in some sense the
worst of both worlds.
To improve that situation, since 14c7fa269e
(check_repository_format_gently(): refuse extensions for old
repositories, 2020-06-05) Git instead ignores extensions in v0 mode.
This way, v0 repositories get the historical (pre-2015) behavior and
maintain compatibility with Git implementations that do not know about
the v1 format. Unfortunately, users had been using this sort of
configuration and this behavior change came to many as a surprise:
- users of "git config --worktree" that had followed its advice
to enable extensions.worktreeConfig (without also increasing the
repository format version) would find their worktree configuration
no longer taking effect
- tools such as copybara[*] that had set extensions.partialClone in
existing repositories (without also increasing the repository format
version) would find that setting no longer taking effect
The behavior introduced in 14c7fa269e might be a good behavior if we
were traveling back in time to 2015, but we're far too late. For some
reason I thought that it was what had been originally implemented and
that it had regressed. Apologies for not doing my research when
14c7fa269e was under development.
Let's return to the behavior we've had since 2015: always act on
extensions.* settings, regardless of repository format version. While
we're here, include some tests to describe the effect on the "upgrade
repository version" code path.
[*] ca76c0b1e1
Reported-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
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).
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
11664196ac
