The index's checksum is not an object ID, so we should not use the
`git_oid` type. Use a byte array for checksum calculation and storage.
Deprecate the `git_indexer_hash` function. Callers should use the new
`git_indexer_name` function which provides a unique packfile name.
libgit2 has two distinct requirements that were previously solved by
`git_buf`. We require:
1. A general purpose string class that provides a number of utility APIs
for manipulating data (eg, concatenating, truncating, etc).
2. A structure that we can use to return strings to callers that they
can take ownership of.
By using a single class (`git_buf`) for both of these purposes, we have
confused the API to the point that refactorings are difficult and
reasoning about correctness is also difficult.
Move the utility class `git_buf` to be called `git_str`: this represents
its general purpose, as an internal string buffer class. The name also
is an homage to Junio Hamano ("gitstr").
The public API remains `git_buf`, and has a much smaller footprint. It
is generally only used as an "out" param with strict requirements that
follow the documentation. (Exceptions exist for some legacy APIs to
avoid breaking callers unnecessarily.)
Utility functions exist to convert a user-specified `git_buf` to a
`git_str` so that we can call internal functions, then converting it
back again.
The information about the type of a revision spec is not information
about the parser. Name it accordingly, so that `git_revparse_mode_t`
is now `git_revspec_t`. Deprecate the old name.
We _dispose_ the contents of objects; we _free_ objects (and their
contents). Update `git_strarray_free` to be `git_strarray_dispose`.
`git_strarray_free` remains as a deprecated proxy function.
We avoid abbreviations where possible; rename git_cred to
git_credential.
In addition, we have standardized on a trailing `_t` for enum types,
instead of using "type" in the name. So `git_credtype_t` has become
`git_credential_t` and its members have become `GIT_CREDENTIAL` instead
of `GIT_CREDTYPE`.
Finally, the source and header files have been renamed to `credential`
instead of `cred`.
Keep previous name and values as deprecated, and include the new header
files from the previous ones.
Static analysis of example code found multiple findings of `printf` usage
where filling value is members of git_indexer_progress object. Specifier
used was for signed int but git_indexer_progress members are typed as
unsigned ints. `printf` specifiers were altered to match type.
