Hi, when starting up, Git will initialize `the_repository` by calling `initialize_the_repository()`. Part of this is also that we set the hash algo of `the_repository` to SHA1, which implicitly sets `the_hash_algo` because it is a macro expanding to `the_repository->hash_algo`. Usually, we eventually set up the correct hash algorithm here once we have properly set up `the_repository` via `setup_git_directory()`. But in some commands we actually don't require a Git repository, and thus we will leave the SHA1 hash algorithm in place. This has led to some subtle bugs when the context really asks for a SHA256 repository, which this patch series corrects for most of the part. Some commands need further work, like for example git-diff(1), where the user might want to have the ability to pick a hash function when run outside of a repository. Ultimately, the last patch then drops the setup of the fallback hash algorithm completely. This will cause `the_hash_algo` to be a `NULL` pointer unless explicitly configured, and thus we now start to crash when it gets accessed without doing so beforehand. This is a rather risky thing to do, but it does catch bugs where we might otherwise accidentally do the wrong thing. And even though I think it is the right thing to do even conceptually, I'd be okay to drop it if folks think that the risk is not worth it. Patrick Patrick Steinhardt (11): path: harden validation of HEAD with non-standard hashes parse-options-cb: only abbreviate hashes when hash algo is known attr: don't recompute default attribute source attr: fix BUG() when parsing attrs outside of repo remote-curl: fix parsing of detached SHA256 heads builtin/rev-parse: allow shortening to more than 40 hex characters builtin/blame: don't access potentially unitialized `the_hash_algo` builtin/bundle: abort "verify" early when there is no repository builtin/diff: explicitly set hash algo when there is no repo builtin/shortlog: don't set up revisions without repo repository: stop setting SHA1 as the default object hash attr.c | 31 ++++++++++++++++++++++--------- builtin/blame.c | 5 ++--- builtin/bundle.c | 5 +++++ builtin/diff.c | 9 +++++++++ builtin/rev-parse.c | 5 ++--- builtin/shortlog.c | 2 +- parse-options-cb.c | 3 ++- path.c | 2 +- remote-curl.c | 19 ++++++++++++++++++- repository.c | 2 -- t/t0003-attributes.sh | 15 +++++++++++++++ t/t0040-parse-options.sh | 17 +++++++++++++++++ t/t1500-rev-parse.sh | 6 ++++++ t/t5550-http-fetch-dumb.sh | 15 +++++++++++++++ 14 files changed, 115 insertions(+), 21 deletions(-) -- 2.44.GIT
Attachment:
signature.asc
Description: PGP signature
