The functions `git_repository_head_for_worktree` and
`git_repository_detached_head_for_worktree` both implement their
own logic to read the HEAD reference file. Use the new function
`git_reference__read_head` instead to unify the code paths.
The function `read_worktree_head` has the logic embedded to construct
the path to `HEAD` in the work tree's git directory, which is quite
useful for other callers. Extract the logic into its own function to
make it reusable by others.
If trying to set the HEAD of a repository to another reference, we have
to check whether this reference is already checked out in another linked
work tree. If it is, we will refuse setting the HEAD and return an
error, but do not set a meaningful error message. Add one.
Currently, we only provide functions to read references directly from a
repository's reference store via e.g. `git_reference_lookup`. But in
some cases, we may want to read files not connected to the current
repository, e.g. when looking up HEAD of connected work trees. This
commit implements `git_reference__read_head`, which will read out and
allocate a reference at an arbitrary path.
When executing `git_futils_mmap_ro_file`, we first try to guess whether
the file is mmapable at all. Part of this check is whether the file is
too large to be mmaped, which can be true on systems with 32 bit
`size_t` types.
The check is performed by first getting the file size wtih
`git_futils_filesize` and then checking whether the returned size can be
represented as `size_t`, returning an error if so. While this test also
catches the case where the function returned an error (as `-1` is not
representable by `size_t`), we will set the misleading error message
"file too large to mmap". But in fact, a negative return value from
`git_futils_filesize` will be caused by the inability to fstat the file.
Fix the error message by handling negative return values separately and
not overwriting the error message in that case.
Short-circuit the call to `git_path_resolve_relative` in case
`git_buf_joinpath` returns an error. While this does not fix any
immediate errors, the resulting code is easier to read and handles
potential new error conditions raised by `git_buf_joinpath`.
In the `_check_dir_contents` function, we first allocate memory for
joining the directory and subdirectory together and afterwards use
`git_buf_joinpath`. While this function in fact should not fail as
memory is already allocated, err on the safe side and check for returned
errors.
The current code in `parse_section_header_ext` is only prepared to
properly handle out-of-memory conditions for the `git_buf` structure.
While very unlikely and probably caused by a programming error, it is
also possible to run into error conditions other than out-of-memory
previous to reaching the actual parsing loop. In these cases, we will
run into undefined behavior as the `rpos` variable is only initialized
after these triggerable errors, but we use it in the cleanup-routine.
Fix the issue by unifying the function's cleanup code with an
`end_error` section, which will not use the `rpos` variable.
POSIX emulation retries should be configurable so that tests can disable
them. In particular, maniacally threading tests may end up trying to
open locked files and need retries, which will slow continuous
integration tests significantly.
This can prevent FILE_SHARED_VIOLATIONS when used in tools such as TortoiseGit TGitCache and FILE_SHARE_DELETE, because files can be opened w/o being locked any more.
Signed-off-by: Sven Strickroth <email@cs-ware.de>
When `git_repository_set_head` is provided a remote reference, update
the reflog with the tag name, like we do with a branch. This helps
consumers match the semantics of `git checkout remote`.
Provide a macro that will allow us to run a function with posix-like
return values multiple times in a retry loop, with an optional cleanup
function called between invocations.
Introduce mapping from windows error codes to errno values. This
allows us to replace our calls to the Windows posix emulation functions
with calls to the Win32 APIs for more fine-grained control over the
emulation.
These mappings match the Windows CRT's mappings for its posix emulation
as they were described to me.
While writing the tree inside of a buffer, we check whether the buffer
runs out of memory after each tree entry. While we set the error code as
soon as we detect the OOM situation, we happily proceed iterating over
the entries. This is not useful at all, as we will try to write into the
buffer repeatedly, which cannot work.
Fix this by exiting as soon as we are OOM.
The `git_tree_entry *entry` variable is defined twice inside of this
function. While this is not a problem currently, remove the shadowing
variable to avoid future confusion.
While we detect errors in `git_treebuilder_write_with_buffer`, we just
exit directly instead of freeing allocated memory. Fix this by
remembering error codes and skipping forward to the function's cleanup
code.
The recent addition of an error code to `pass_whole_blame` in ff8d2eb15
(blame_git: check return value of object lookup, 2017-03-20) introduced
a spurious goto. Remove it.
The config and attrcache file reading code would attempt to load a file
in a home directory by expanding the `~` and looking for the file, using
`git_sysdir_find_global_file`. If the file was not found, the error
handling would look for the literal path, eg `~/filename.txt`.
Use the new `git_config_expand_global_file` instead, which allows us to
get the path to the file separately, when the path is prefixed with
`~/`, and fail with a not found error without falling back to looking
for the literal path.
Provide a mechanism for callers to expand the full path of a file in the
global configuration directory (that is to say, the home directory) even
if the file doesn't necessarily exist. This lets callers use their own
logic for building paths separate from handling file existence.
