Merge pull request #10044 from edolstra/empty-git-repos

Handle empty Git repositories / workdirs
This commit is contained in:
Théophane Hufschmitt 2024-02-20 14:01:23 +01:00 committed by GitHub
commit d2c6a93bd5
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GPG key ID: B5690EEEBB952194
8 changed files with 67 additions and 24 deletions

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@ -467,13 +467,13 @@ EvalState::~EvalState()
void EvalState::allowPath(const Path & path)
{
if (auto rootFS2 = rootFS.dynamic_pointer_cast<AllowListInputAccessor>())
rootFS2->allowPath(CanonPath(path));
rootFS2->allowPrefix(CanonPath(path));
}
void EvalState::allowPath(const StorePath & storePath)
{
if (auto rootFS2 = rootFS.dynamic_pointer_cast<AllowListInputAccessor>())
rootFS2->allowPath(CanonPath(store->toRealPath(storePath)));
rootFS2->allowPrefix(CanonPath(store->toRealPath(storePath)));
}
void EvalState::allowAndSetStorePathString(const StorePath & storePath, Value & v)

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@ -51,33 +51,33 @@ void FilteringInputAccessor::checkAccess(const CanonPath & path)
struct AllowListInputAccessorImpl : AllowListInputAccessor
{
std::set<CanonPath> allowedPaths;
std::set<CanonPath> allowedPrefixes;
AllowListInputAccessorImpl(
ref<InputAccessor> next,
std::set<CanonPath> && allowedPaths,
std::set<CanonPath> && allowedPrefixes,
MakeNotAllowedError && makeNotAllowedError)
: AllowListInputAccessor(SourcePath(next), std::move(makeNotAllowedError))
, allowedPaths(std::move(allowedPaths))
, allowedPrefixes(std::move(allowedPrefixes))
{ }
bool isAllowed(const CanonPath & path) override
{
return path.isAllowed(allowedPaths);
return path.isAllowed(allowedPrefixes);
}
void allowPath(CanonPath path) override
void allowPrefix(CanonPath prefix) override
{
allowedPaths.insert(std::move(path));
allowedPrefixes.insert(std::move(prefix));
}
};
ref<AllowListInputAccessor> AllowListInputAccessor::create(
ref<InputAccessor> next,
std::set<CanonPath> && allowedPaths,
std::set<CanonPath> && allowedPrefixes,
MakeNotAllowedError && makeNotAllowedError)
{
return make_ref<AllowListInputAccessorImpl>(next, std::move(allowedPaths), std::move(makeNotAllowedError));
return make_ref<AllowListInputAccessorImpl>(next, std::move(allowedPrefixes), std::move(makeNotAllowedError));
}
bool CachingFilteringInputAccessor::isAllowed(const CanonPath & path)

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@ -54,18 +54,19 @@ struct FilteringInputAccessor : InputAccessor
};
/**
* A wrapping `InputAccessor` that checks paths against an allow-list.
* A wrapping `InputAccessor` that checks paths against a set of
* allowed prefixes.
*/
struct AllowListInputAccessor : public FilteringInputAccessor
{
/**
* Grant access to the specified path.
* Grant access to the specified prefix.
*/
virtual void allowPath(CanonPath path) = 0;
virtual void allowPrefix(CanonPath prefix) = 0;
static ref<AllowListInputAccessor> create(
ref<InputAccessor> next,
std::set<CanonPath> && allowedPaths,
std::set<CanonPath> && allowedPrefixes,
MakeNotAllowedError && makeNotAllowedError);
using FilteringInputAccessor::FilteringInputAccessor;

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@ -2,6 +2,7 @@
#include "fs-input-accessor.hh"
#include "input-accessor.hh"
#include "filtering-input-accessor.hh"
#include "memory-input-accessor.hh"
#include "cache.hh"
#include "finally.hh"
#include "processes.hh"
@ -942,17 +943,21 @@ ref<InputAccessor> GitRepoImpl::getAccessor(const Hash & rev, bool exportIgnore)
ref<InputAccessor> GitRepoImpl::getAccessor(const WorkdirInfo & wd, bool exportIgnore, MakeNotAllowedError makeNotAllowedError)
{
auto self = ref<GitRepoImpl>(shared_from_this());
/* In case of an empty workdir, return an empty in-memory tree. We
cannot use AllowListInputAccessor because it would return an
error for the root (and we can't add the root to the allow-list
since that would allow access to all its children). */
ref<InputAccessor> fileAccessor =
AllowListInputAccessor::create(
makeFSInputAccessor(path),
std::set<CanonPath> { wd.files },
std::move(makeNotAllowedError));
if (exportIgnore) {
wd.files.empty()
? makeEmptyInputAccessor()
: AllowListInputAccessor::create(
makeFSInputAccessor(path),
std::set<CanonPath> { wd.files },
std::move(makeNotAllowedError)).cast<InputAccessor>();
if (exportIgnore)
return make_ref<GitExportIgnoreInputAccessor>(self, fileAccessor, std::nullopt);
}
else {
else
return fileAccessor;
}
}
ref<GitFileSystemObjectSink> GitRepoImpl::getFileSystemObjectSink()

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@ -158,6 +158,8 @@ std::vector<PublicKey> getPublicKeys(const Attrs & attrs)
} // end namespace
static const Hash nullRev{HashAlgorithm::SHA1};
struct GitInputScheme : InputScheme
{
std::optional<Input> inputFromURL(const ParsedURL & url, bool requireTree) const override
@ -708,10 +710,12 @@ struct GitInputScheme : InputScheme
if (auto ref = repo->getWorkdirRef())
input.attrs.insert_or_assign("ref", *ref);
auto rev = repoInfo.workdirInfo.headRev.value();
/* Return a rev of 000... if there are no commits yet. */
auto rev = repoInfo.workdirInfo.headRev.value_or(nullRev);
input.attrs.insert_or_assign("rev", rev.gitRev());
input.attrs.insert_or_assign("revCount", getRevCount(repoInfo, repoInfo.url, rev));
input.attrs.insert_or_assign("revCount",
rev == nullRev ? 0 : getRevCount(repoInfo, repoInfo.url, rev));
verifyCommit(input, repo);
} else {

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@ -20,4 +20,10 @@ ref<MemoryInputAccessor> makeMemoryInputAccessor()
return make_ref<MemoryInputAccessorImpl>();
}
ref<InputAccessor> makeEmptyInputAccessor()
{
static auto empty = makeMemoryInputAccessor().cast<InputAccessor>();
return empty;
}
}

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@ -13,4 +13,6 @@ struct MemoryInputAccessor : InputAccessor
ref<MemoryInputAccessor> makeMemoryInputAccessor();
ref<InputAccessor> makeEmptyInputAccessor();
}

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@ -271,3 +271,28 @@ git -C "$repo" add hello .gitignore
git -C "$repo" commit -m 'Bla1'
cd "$repo"
path11=$(nix eval --impure --raw --expr "(builtins.fetchGit ./.).outPath")
# Test a workdir with no commits.
empty="$TEST_ROOT/empty"
git init "$empty"
emptyAttrs='{ lastModified = 0; lastModifiedDate = "19700101000000"; narHash = "sha256-pQpattmS9VmO3ZIQUFn66az8GSmB4IvYhTTCFn6SUmo="; rev = "0000000000000000000000000000000000000000"; revCount = 0; shortRev = "0000000"; submodules = false; }'
[[ $(nix eval --impure --expr "builtins.removeAttrs (builtins.fetchGit $empty) [\"outPath\"]") = $emptyAttrs ]]
echo foo > "$empty/x"
[[ $(nix eval --impure --expr "builtins.removeAttrs (builtins.fetchGit $empty) [\"outPath\"]") = $emptyAttrs ]]
git -C "$empty" add x
[[ $(nix eval --impure --expr "builtins.removeAttrs (builtins.fetchGit $empty) [\"outPath\"]") = '{ lastModified = 0; lastModifiedDate = "19700101000000"; narHash = "sha256-wzlAGjxKxpaWdqVhlq55q5Gxo4Bf860+kLeEa/v02As="; rev = "0000000000000000000000000000000000000000"; revCount = 0; shortRev = "0000000"; submodules = false; }' ]]
# Test a repo with an empty commit.
git -C "$empty" rm -f x
git -C "$empty" config user.email "foobar@example.com"
git -C "$empty" config user.name "Foobar"
git -C "$empty" commit --allow-empty --allow-empty-message --message ""
nix eval --impure --expr "let attrs = builtins.fetchGit $empty; in assert attrs.lastModified != 0; assert attrs.rev != \"0000000000000000000000000000000000000000\"; assert attrs.revCount == 1; true"