git/t/t1302-repo-version.sh

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#!/bin/sh
#
# Copyright (c) 2007 Nguyễn Thái Ngọc Duy
#
test_description='Test repository version check'
. ./test-lib.sh
test_expect_success 'setup' '
test_oid_cache <<-\EOF &&
version sha1:0
version sha256:1
EOF
cat >test.patch <<-\EOF &&
diff --git a/test.txt b/test.txt
new file mode 100644
--- /dev/null
+++ b/test.txt
@@ -0,0 +1 @@
+123
EOF
test_create_repo "test" &&
test_create_repo "test2" &&
git config --file=test2/.git/config core.repositoryformatversion 99
'
test_expect_success 'gitdir selection on normal repos' '
echo $(test_oid version) >expect &&
git config core.repositoryformatversion >actual &&
git -C test config core.repositoryformatversion >actual2 &&
test_cmp expect actual &&
test_cmp expect actual2
'
test_expect_success 'gitdir selection on unsupported repo' '
# Make sure it would stop at test2, not trash
config: only read .git/config from configured repos When git_config() runs, it looks in the system, user-wide, and repo-level config files. It gets the latter by calling git_pathdup(), which in turn calls get_git_dir(). If we haven't set up the git repository yet, this may simply return ".git", and we will look at ".git/config". This seems like it would be helpful (presumably we haven't set up the repository yet, so it tries to find it), but it turns out to be a bad idea for a few reasons: - it's not sufficient, and therefore hides bugs in a confusing way. Config will be respected if commands are run from the top-level of the working tree, but not from a subdirectory. - it's not always true that we haven't set up the repository _yet_; we may not want to do it at all. For instance, if you run "git init /some/path" from inside another repository, it should not load config from the existing repository. - there might be a path ".git/config", but it is not the actual repository we would find via setup_git_directory(). This may happen, e.g., if you are storing a git repository inside another git repository, but have munged one of the files in such a way that the inner repository is not valid (e.g., by removing HEAD). We have at least two bugs of the second type in git-init, introduced by ae5f677 (lazily load core.sharedrepository, 2016-03-11). It causes init to use git_configset(), which loads all of the config, including values from the current repo (if any). This shows up in two ways: 1. If we happen to be in an existing repository directory, we'll read and respect core.sharedrepository from it, even though it should have no bearing on the new repository. A new test in t1301 covers this. 2. Similarly, if we're in an existing repo that sets core.logallrefupdates, that will cause init to fail to set it in a newly created repository (because it thinks that the user's templates already did so). A new test in t0001 covers this. We also need to adjust an existing test in t1302, which gives another example of why this patch is an improvement. That test creates an embedded repository with a bogus core.repositoryformatversion of "99". It wants to make sure that we actually stop at the bogus repo rather than continuing upward to find the outer repo. So it checks that "git config core.repositoryformatversion" returns 99. But that only works because we blindly read ".git/config", even though we _know_ we're in a repository whose vintage we do not understand. After this patch, we avoid reading config from the unknown vintage repository at all, which is a safer choice. But we need to tweak the test, since core.repositoryformatversion will not return 99; it will claim that it could not find the variable at all. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-13 03:24:15 +00:00
test_expect_code 1 git -C test2 config core.repositoryformatversion >actual
'
test_expect_success 'gitdir not required mode' '
git apply --stat test.patch &&
git -C test apply --stat ../test.patch &&
git -C test2 apply --stat ../test.patch
'
test_expect_success 'gitdir required mode' '
git apply --check --index test.patch &&
git -C test apply --check --index ../test.patch &&
test_must_fail git -C test2 apply --check --index ../test.patch
Sane use of test_expect_failure 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>
2008-02-01 09:50:53 +00:00
'
introduce "extensions" form of core.repositoryformatversion 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>
2015-06-23 10:53:58 +00:00
check_allow () {
git rev-parse --git-dir >actual &&
echo .git >expect &&
test_cmp expect actual
}
check_abort () {
test_must_fail git rev-parse --git-dir
}
# avoid git-config, since it cannot be trusted to run
# in a repository with a broken version
mkconfig () {
echo '[core]' &&
echo "repositoryformatversion = $1" &&
shift &&
if test $# -gt 0; then
echo '[extensions]' &&
for i in "$@"; do
echo "$i"
done
fi
}
while read outcome version extensions; do
test_expect_success "$outcome version=$version $extensions" "
mkconfig $version $extensions >.git/config &&
check_${outcome}
"
done <<\EOF
allow 0
allow 1
allow 1 noop
abort 1 no-such-extension
allow 0 no-such-extension
verify_repository_format(): complain about new extensions in v0 repo We made the mistake in the past of respecting extensions.* even when the repository format version was set to 0. This is bad because forgetting to bump the repository version means that older versions of Git (which do not know about our extensions) won't complain. I.e., it's not a problem in itself, but it means your repository is in a state which does not give you the protection you think you're getting from older versions. For compatibility reasons, we are stuck with that decision for existing extensions. However, we'd prefer not to extend the damage further. We can do that by catching any newly-added extensions and complaining about the repository format. Note that this is a pretty heavy hammer: we'll refuse to work with the repository at all. A lesser option would be to ignore (possibly with a warning) any new extensions. But because of the way the extensions are handled, that puts the burden on each new extension that is added to remember to "undo" itself (because they are handled before we know for sure whether we are in a v1 repo or not, since we don't insist on a particular ordering of config entries). So one option would be to rewrite that handling to record any new extensions (and their values) during the config parse, and then only after proceed to handle new ones only if we're in a v1 repository. But I'm not sure if it's worth the trouble: - ignoring extensions is likely to end up with broken results anyway (e.g., ignoring a proposed objectformat extension means parsing any object data is likely to encounter errors) - this is a sign that whatever tool wrote the extension field is broken. We may be better off notifying immediately and forcefully so that such tools don't even appear to work accidentally. The only downside is that fixing the situation is a little tricky, because programs like "git config" won't want to work with the repository. But: git config --file=.git/config core.repositoryformatversion 1 should still suffice. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-16 12:25:13 +00:00
allow 0 noop
abort 0 noop-v1
allow 1 noop-v1
introduce "extensions" form of core.repositoryformatversion 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>
2015-06-23 10:53:58 +00:00
EOF
test_expect_success 'precious-objects allowed' '
mkconfig 1 preciousObjects >.git/config &&
check_allow
'
test_expect_success 'precious-objects blocks destructive repack' '
test_must_fail git repack -ad
'
test_expect_success 'other repacks are OK' '
test_commit foo &&
git repack
'
test_expect_success 'precious-objects blocks prune' '
test_must_fail git prune
'
test_expect_success 'gc runs without complaint' '
git gc
'
test_done