Re: What's cooking in git.git (Oct 2023, #01; Mon, 2)

> * eb/hash-transition (2023-10-02) 30 commits
>  - t1016-compatObjectFormat: add tests to verify the conversion between objects
>  - t1006: test oid compatibility with cat-file
>  - t1006: rename sha1 to oid
>  - test-lib: compute the compatibility hash so tests may use it
>  - builtin/ls-tree: let the oid determine the output algorithm
>  - object-file: handle compat objects in check_object_signature
>  - tree-walk: init_tree_desc take an oid to get the hash algorithm
>  - builtin/cat-file: let the oid determine the output algorithm
>  - rev-parse: add an --output-object-format parameter
>  - repository: implement extensions.compatObjectFormat
>  - object-file: update object_info_extended to reencode objects
>  - object-file-convert: convert commits that embed signed tags
>  - object-file-convert: convert commit objects when writing
>  - object-file-convert: don't leak when converting tag objects
>  - object-file-convert: convert tag objects when writing
>  - object-file-convert: add a function to convert trees between algorithms
>  - object: factor out parse_mode out of fast-import and tree-walk into in object.h
>  - cache: add a function to read an OID of a specific algorithm
>  - tag: sign both hashes
>  - commit: export add_header_signature to support handling signatures on tags
>  - commit: convert mergetag before computing the signature of a commit
>  - commit: write commits for both hashes
>  - object-file: add a compat_oid_in parameter to write_object_file_flags
>  - object-file: update the loose object map when writing loose objects
>  - loose: compatibilty short name support
>  - loose: add a mapping between SHA-1 and SHA-256 for loose objects
>  - repository: add a compatibility hash algorithm
>  - object-names: support input of oids in any supported hash
>  - oid-array: teach oid-array to handle multiple kinds of oids
>  - object-file-convert: stubs for converting from one object format to another
>
>  Teach a repository to work with both SHA-1 and SHA-256 hash algorithms.
>
>  Breaks a few CI jobs when merged to 'seen'.
>  cf. <xmqqbkdmjbkp.fsf@gitster.g>