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.
git's default rename limit is 1000, ours should match.
When a split src gets turned into a rename, it should also lose the IS_RENAME_TARGET flag, so that it doesn't get processed in a subsequent iteration as a rename target. Doing so can cause an assertion failure because it no longer has the SPLIT flag. Fixes #5811.
The new git_repository_workdir_path function does error checking on working directory inputs on Windows; use it to construct paths within working directories.
Propagate failures caused by pool initialization errors.
libgit2 does not use `type_t` suffixes as it's redundant; thus, rename `git_iterator_type_t` to `git_iterator_t` for consistency.
Instead of using a signed type (`off_t`) use a new `git_object_size_t` for the sizes of objects.
Our file utils functions all have a "futils" prefix, e.g. `git_futils_touch`. One would thus naturally guess that their definitions and implementation would live in files "futils.h" and "futils.c", respectively, but in fact they live in "fileops.h". Rename the files to match expectations.
The only function that is named `issomething` (without underscore) was `git_oid_iszero`. Rename it to `git_oid_is_zero` for consistency with the rest of the library.