When stashing the workdir tree, examine the index as well. Using
a mechanism similar to `git_diff_tree_to_workdir_with_index`
allows us to determine that a file was added in the index and
subsequently modified in the working directory. Without examining
the index, we would erroneously believe that this file was
untracked and fail to include it in the working directory tree.
Use a slightly modified `git_diff_tree_to_workdir_with_index` in
order to avoid some of the behavior custom to `git diff`. In
particular, be sure to include the working directory side of a
file when it was deleted in the index.
This is something we do on re-init but not when opening a
repository. This hasn't particularly mattered up to now as the version
has been 0 ever since the first release of git, but the times, they're
a-changing and we will soon see version 1 in the wild. We need to make
sure we don't open those.
If an index entry for a file that is not in HEAD is in conflicted state,
when diffing HEAD with the index, the status field of the corresponding git_diff_delta was incorrectly reported as GIT_DELTA_ADDED instead of GIT_DELTA_CONFLICTED.
This was due to handle_unmatched_new_item() initially setting the status
to GIT_DELTA_CONFLICTED but then overriding it later with GIT_DELTA_ADDED.
This allows the user to look up fields which we don't parse in libgit2,
and allows them to access gpgsig or mergetag fields if they wish to
check the signature.
When an entry has a racy timestamp, we need to check whether the file
itself has changed since we put its entry in the index. Only then do we
smudge the size field to force a check the next time around.
When a file on the workdir has the same or a newer timestamp than the
index, we need to perform a full check of the contents, as the update of
the file may have happened just after we wrote the index.
The iterator changes are such that we can reach inside the workdir
iterator from the diff, though it may be better to have an accessor
instead of moving these structs into the header.
When updating the index during a diff, preserve the original mode,
which prevents us from dropping the mode to what we have interpreted
as on our system (eg, what the working directory claims it to be,
which may be a lie on some systems.)
This is used by the submodule in order to figure out if the index has
changed since it last read it. Using a timestamp is racy, so let's make
it use the checksum, just like we now do for reloading the index itself.
We currently use a timetamp to check whether an index file has been
modified since we last read it, but this is racy. If two updates happen
in the same second and we read after the first one, we won't detect the
second one.
Instead read the SHA-1 checksum of the file, which are its last 20 bytes which
gives us a sure-fire way to detect whether the file has changed since we
last read it.
As we're now keeping track of it, expose an accessor to this data.
When checking out some file 'foo' that has been modified in the
working directory, allow the checkout to proceed (do not conflict)
if 'foo' is identical to the target of the checkout.
In order to avoid racy-git, we zero out the file size for entries with
the same timestamp as the index (or during the initial checkout). This
is the case in a couple of crlf tests, as the code is fast enough to do
everything in the same second.
As we know that we do not perform the modification just after writing
out the index, which is what this is designed to work around, tick the
mtime of the index file such that it doesn't agree with the files
anymore, and we do not zero out these entries.
If a file entry has the same timestamp as the index itself, it is
considered racily-clean, as it may have been modified after the index
was written, but during the same second. We take extra steps to check
the contents, but this is just one part of avoiding races.
For files which do have changes but have not been updated in the index,
updating the on-disk index means updating its timestamp, which means we
would no longer recognise these entries as racy and we would trust the
timestamp to tell us whether they have changed.
In order to work around this, git zeroes out the file-size field in
entries with the same timestamp as the index in order to force the next
diff to check the contents. Do so in libgit2 as well.
Arguably all uses of readdir_r are unnecessary, but in this case
especially so, as the directory handle only exists within this function,
so we don't race with anybody.
Introduce a new binary diff callback to provide the actual binary
delta contents to callers. Create this data from the diff contents
(instead of directly from the ODB) to support binary diffs including
the workdir, not just things coming out of the ODB.
The read and write callbacks passed to SSLSetIOFuncs() have been
rewritten to match the implementation used on opensource.apple.com and
other open source projects like VLC.
This change also fixes a bug where the read callback could get into
an infinite loop when 0 bytes were read.
Some tools create multiple author fields. git is rather lax when parsing
them, although fsck does complain about them. This means that they exist
in the wild.
As it's not too taxing to check for them, and there shouldn't be a
noticeable slowdown when dealing with correct commits, add logic to skip
over these extra fields when parsing the commit.
When we hit an error writing to the next stream from a file, we jump to
'done' which currently skips over closing the file descriptor.
Make sure to close the descriptor if it has been set to a valid value.
