If this extension is used in a repository, then no
operations should run which may drop objects from the object
storage. This can be useful if you are sharing that storage
with other repositories whose refs you cannot see.
For instance, if you do:
$ git clone -s parent child
$ git -C parent config extensions.preciousObjects true
$ git -C parent config core.repositoryformatversion 1
you now have additional safety when running git in the
parent repository. Prunes and repacks will bail with an
error, and `git gc` will skip those operations (it will
continue to pack refs and do other non-object operations).
Older versions of git, when run in the repository, will
fail on every operation.
Note that we do not set the preciousObjects extension by
default when doing a "clone -s", as doing so breaks
backwards compatibility. It is a decision the user should
make explicitly.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Normally we try to avoid bumps of the whole-repository
core.repositoryformatversion field. However, it is
unavoidable if we want to safely change certain aspects of
git in a backwards-incompatible way (e.g., modifying the set
of ref tips that we must traverse to generate a list of
unreachable, safe-to-prune objects).
If we were to bump the repository version for every such
change, then any implementation understanding version `X`
would also have to understand `X-1`, `X-2`, and so forth,
even though the incompatibilities may be in orthogonal parts
of the system, and there is otherwise no reason we cannot
implement one without the other (or more importantly, that
the user cannot choose to use one feature without the other,
weighing the tradeoff in compatibility only for that
particular feature).
This patch documents the existing repositoryformatversion
strategy and introduces a new format, "1", which lets a
repository specify that it must run with an arbitrary set of
extensions. This can be used, for example:
- to inform git that the objects should not be pruned based
only on the reachability of the ref tips (e.g, because it
has "clone --shared" children)
- that the refs are stored in a format besides the usual
"refs" and "packed-refs" directories
Because we bump to format "1", and because format "1"
requires that a running git knows about any extensions
mentioned, we know that older versions of the code will not
do something dangerous when confronted with these new
formats.
For example, if the user chooses to use database storage for
refs, they may set the "extensions.refbackend" config to
"db". Older versions of git will not understand format "1"
and bail. Versions of git which understand "1" but do not
know about "refbackend", or which know about "refbackend"
but not about the "db" backend, will refuse to run. This is
annoying, of course, but much better than the alternative of
claiming that there are no refs in the repository, or
writing to a location that other implementations will not
read.
Note that we are only defining the rules for format 1 here.
We do not ever write format 1 ourselves; it is a tool that
is meant to be used by users and future extensions to
provide safety with older implementations.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Doing:
GIT_CONFIG=foo git config ...
is equivalent to:
git config --file=foo ...
The latter is easier to read and slightly less error-prone,
because of issues with one-shot variables and shell
functions (e.g., you cannot use the former with
test_must_fail).
Note that we explicitly leave one case in t1300 which checks
the same operation on both GIT_CONFIG and "git config
--file". They are equivalent in the code these days, but
this will make sure it remains so.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Breaks in a test assertion's && chain can potentially hide
failures from earlier commands in the chain.
Commands intended to fail should be marked with !, test_must_fail, or
test_might_fail. The examples in this patch do not require that.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This test is from 2007, which is late enough for the style to be
recognizably modern but still a while ago. Freshen it up to
follow new best practices:
- guard setup commands with test_expect_setup, so errors at
that stage can be caught;
- use <<\EOF in preference to <<EOF, to save reviewers the
trouble of looking for variable interpolations;
- use test_cmp instead of test "$foo" = "$bar", for better
output with -v on failure;
- indent commands in subshells and let them span multiple lines;
- combine the two "gitdir required mode" tests that do not make
as much sense alone.
Cc: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Format the subshells introduced by the previous patch (Several tests:
cd inside subshell instead of around, 2010-09-06) like so:
(
cd subdir &&
...
) &&
This is generally easier to read and has the nice side-effect that
this patch will show what commands are used in the subshell, making
it easier to check for lost environment variables and similar
behavior changes.
Cc: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fixed all places where it was a straightforward change from cd'ing into a
directory and back via "cd .." to a cd inside a subshell.
Found these places with "git grep -w "cd \.\.".
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch changes every occurrence of "! git" -- with the meaning
that a git call has to gracefully fail -- into "test_must_fail git".
This is useful to
- make sure the test does not fail because of a signal,
e.g. SIGSEGV, and
- advertise the use of "test_must_fail" for new tests.
Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Originally, test_expect_failure was designed to be the opposite
of test_expect_success, but this was a bad decision. Most tests
run a series of commands that leads to the single command that
needs to be tested, like this:
test_expect_{success,failure} 'test title' '
setup1 &&
setup2 &&
setup3 &&
what is to be tested
'
And expecting a failure exit from the whole sequence misses the
point of writing tests. Your setup$N that are supposed to
succeed may have failed without even reaching what you are
trying to test. The only valid use of test_expect_failure is to
check a trivial single command that is expected to fail, which
is a minority in tests of Porcelain-ish commands.
This large-ish patch rewrites all uses of test_expect_failure to
use test_expect_success and rewrites the condition of what is
tested, like this:
test_expect_success 'test title' '
setup1 &&
setup2 &&
setup3 &&
! this command should fail
'
test_expect_failure is redefined to serve as a reminder that
that test *should* succeed but due to a known breakage in git it
currently does not pass. So if git-foo command should create a
file 'bar' but you discovered a bug that it doesn't, you can
write a test like this:
test_expect_failure 'git-foo should create bar' '
rm -f bar &&
git foo &&
test -f bar
'
This construct acts similar to test_expect_success, but instead
of reporting "ok/FAIL" like test_expect_success does, the
outcome is reported as "FIXED/still broken".
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This pushes check_repository_format() (actually _gently() version)
to setup_git_directory_gently() in order to prevent from
using unsupported repositories.
New setup_git_directory_gently()'s behaviour is stop searching
for a valid gitdir and return as if there is no gitdir if a
unsupported repository is found. Warning will be thrown in these
cases.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
