Only provide the empty tree internally, which matches git's behavior.
If we provide the empty blob then any users trying to write it with
libgit2 would omit it from actually landing in the odb, which appear
to git proper as a broken repository (missing that object).
The `SSLCopyPeerTrust` call can succeed but fail to return a trust
object if it can't load the certificate chain and thus cannot check the
validity of a certificate. This can lead to us calling `CFRelease` on a
`NULL` trust object, causing a crash.
Handle this by returning ECERTIFICATE.
Since writing multiple objects may all already exist in a single
packfile, avoid freshening that packfile repeatedly in a tight loop.
Instead, only freshen pack files every 2 seconds.
Don't try to determine when sysdirs are uninitialized. Instead, simply
initialize them all at `git_libgit2_init` time and never try to
reinitialize, except when consumers explicitly call `git_sysdir_set`.
Looking at the buffer length is especially problematic, since there may
no appropriate path for that value. (For example, the Windows-specific
programdata directory has no value on non-Windows machines.)
Previously we would continually trying to re-lookup these values,
which could get racy if two different threads are each calling
`git_sysdir_get` and trying to lookup / clear the value simultaneously.
According to git-fetch(1), "[t]he colon can be omitted when <dst>
is empty." So according to git, the refspec "refs/heads/master"
is the same as the refspec "refs/heads/master:" when fetching
changes. When trying to fetch from a remote with a trailing
colon with libgit2, though, the fetch actually fails while it
works when the trailing colon is left out. So obviously, libgit2
does _not_ treat these two refspec formats the same for fetches.
The problem results from parsing refspecs, where the resulting
refspec has its destination set to an empty string in the case of
a trailing colon and to a `NULL` pointer in the case of no
trailing colon. When passing this to our DWIM machinery, the
empty string gets translated to "refs/heads/", which is simply
wrong.
Fix the problem by having the parsing machinery treat both cases
the same for fetch refspecs.
After 1cd65991, we were passing a pointer to an `unsigned long` to
a function that now expected a pointer to a `size_t`. These types
differ on 64-bit Windows, which means that we trash the stack.
Use `size_t`s in the packbuilder to avoid this.
Somehow I ended up with the following in my ~/.gitconfig:
[branch "master"]
remote = origin
merge = master
rebase = true
I assume something went crazy while I was running the git.git tests
some time ago, and that I never noticed until now.
This is not a good configuration, but it shouldn't cause problems. But
it does. Specifically, if you have this in your config, and you
perform the following set of actions:
create a remote
fetch from that remote
create a branch off of the remote master branch called "master"
delete the branch
delete the remote
The remote delete fails with the message "Could not find key
'branch.master.rebase' to delete". This is because it's iterating over
the config entries (including the ones in the global config) and
believes that there is a master branch which must therefore have these
config keys.
https://github.com/libgit2/libgit2/issues/3856
Ensure that we include conflicts when calling `git_index_read_index`,
which will remove conflicts in the index that do not exist in the new
target, and will add conflicts from the new target.
Most of `git_index_read_index` is common to reading any iterator.
Refactor it out in case we want to implement `read_tree` in terms of it
in the future.
When we create a blame origin, we try to look up the blob that is
to be blamed at a certain revision. When this lookup fails, e.g.
because the file did not exist at that certain revision, we fail
to create the blame origin and return `NULL`. The blame origin
that we have just allocated is thereby free'd with
`origin_decref`.
The `origin_decref` function does not only decrement reference
counts for the blame origin, though, but also for its commit and
blob. When this is done in the error case, we will cause an
uneven reference count for these objects. This may result in
hard-to-debug failures at seemingly unrelated code paths, where
we try to access these objects when they in fact have already
been free'd.
Fix the issue by refactoring `make_origin` such that we only
allocate the object after the only function that may fail so that
we do not have to call `origin_decref` at all. Also fix the
`pass_blame` function, which indirectly calls `make_origin`, to
free the commit when `make_origin` failed.
When showing copy information because we are duplicating contents,
for example, when performing a `diff --find-copies-harder -M100 -B100`,
then show copy from/to lines in a patch, and do not show context.
Ensure that we can also parse such patches.
find_repo had a complex loop and heavily nested conditionals, making it
difficult to follow. Simplify this as much as possible:
- Separate assignments from conditionals.
- Check the complex loop condition in the only place it can change.
- Break out of the loop on error, rather than going through the rest of
the loop body first.
- Handle error cases by immediately breaking, rather than nesting
conditionals.
- Free repo_link unconditionally on the way out of the function, rather
than in multiple places.
- Add more comments on the remaining complex steps.
git_repository_open_ext provides parameters for the start path, whether
to search across filesystems, and what ceiling directories to stop at.
git commands have standard environment variables and defaults for each
of those, as well as various other parameters of the repository. To
avoid duplicate environment variable handling in users of libgit2, add a
GIT_REPOSITORY_OPEN_FROM_ENV flag, which makes git_repository_open_ext
automatically handle the appropriate environment variables. Commands
that intend to act just like those built into git itself can use this
flag to get the expected default behavior.
git_repository_open_ext with the GIT_REPOSITORY_OPEN_FROM_ENV flag
respects $GIT_DIR, $GIT_DISCOVERY_ACROSS_FILESYSTEM,
$GIT_CEILING_DIRECTORIES, $GIT_INDEX_FILE, $GIT_NAMESPACE,
$GIT_OBJECT_DIRECTORY, and $GIT_ALTERNATE_OBJECT_DIRECTORIES. In the
future, when libgit2 gets worktree support, git_repository_open_env will
also respect $GIT_WORK_TREE and $GIT_COMMON_DIR; until then,
git_repository_open_ext with this flag will error out if either
$GIT_WORK_TREE or $GIT_COMMON_DIR is set.
GIT_REPOSITORY_OPEN_NO_SEARCH does not search up through parent
directories, but still tries the specified path both directly and with
/.git appended. GIT_REPOSITORY_OPEN_BARE avoids appending /.git, but
opens the repository in bare mode even if it has a working directory.
To support the semantics git uses when given $GIT_DIR in the
environment, provide a new GIT_REPOSITORY_OPEN_NO_DOTGIT flag to not try
appending /.git.
git only checks ceiling directories when its search ascends to a parent
directory. A ceiling directory matching the starting directory will not
prevent git from finding a repository in the starting directory or a
parent directory. libgit2 handled the former case correctly, but
differed from git in the latter case: given a ceiling directory matching
the starting directory, but no repository at the starting directory,
libgit2 would stop the search at that point rather than finding a
repository in a parent directory.
Test case using git command-line tools:
/tmp$ git init x
Initialized empty Git repository in /tmp/x/.git/
/tmp$ cd x/
/tmp/x$ mkdir subdir
/tmp/x$ cd subdir/
/tmp/x/subdir$ GIT_CEILING_DIRECTORIES=/tmp/x git rev-parse --git-dir
fatal: Not a git repository (or any of the parent directories): .git
/tmp/x/subdir$ GIT_CEILING_DIRECTORIES=/tmp/x/subdir git rev-parse --git-dir
/tmp/x/.git
Fix the testsuite to test this case (in one case fixing a test that
depended on the current behavior), and then fix find_repo to handle this
case correctly.
In the process, simplify and document the logic in find_repo():
- Separate the concepts of "currently checking a .git directory" and
"number of iterations left before going further counts as a search"
into two separate variables, in_dot_git and min_iterations.
- Move the logic to handle in_dot_git and append /.git to the top of the
loop.
- Only search ceiling_dirs and find ceiling_offset after running out of
min_iterations; since ceiling_offset only tracks the longest matching
ceiling directory, if ceiling_dirs contained both the current
directory and a parent directory, this change makes find_repo stop the
search at the parent directory.
Avoid declaring old-style functions without any parameters.
Functions not accepting any parameters should be declared with
`void fn(void)`. See ISO C89 $3.5.4.3.
The old pthread-file did re-implement the pthreads API with exact symbol
matching. As the thread-abstraction has now been split up between Unix- and
Windows-specific files within the `git_` namespace to avoid symbol-clashes
between libgit2 and pthreads, the rewritten wrappers have nothing to do with
pthreads anymore.
Rename the Windows-specific pthread-files to honor this change.
The thread local storage is used to hold some global state that
is dynamically allocated and should be freed upon exit. On
Windows, we clean up the C run-time right after execution of
registered shutdown callbacks and before cleaning up the TLS.
When we clean up the CRT, we also cause it to analyze for memory
leaks. As we did not free the TLS yet this will lead to false
positives.
Fix the issue by first freeing the TLS and cleaning up the CRT
only afterwards.
When removing an entry from the index by its position, we first
retrieve the position from the index's entries and then try to
remove the retrieved value from the index map with
`DELETE_IN_MAP`. When `index_remove_entry` returns `NULL` we try
to feed it into the `DELETE_IN_MAP` macro, which will
unconditionally call `idxentry_hash` and then happily dereference
the `NULL` entry pointer.
Fix the issue by not passing a `NULL` entry into `DELETE_IN_MAP`.
When we receive a packet of exactly four bytes encoding its
length as those four bytes it can be treated as an empty line.
While it is not really specified how those empty lines should be
treated, we currently ignore them and do not return an error when
trying to parse it but simply advance the data pointer.
Callers invoking `git_pkt_parse_line` are currently not prepared
to handle this case as they do not explicitly check this case.
While they could always reset the passed out-pointer to `NULL`
before calling `git_pkt_parse_line` and determine if the pointer
has been set afterwards, it makes more sense to update
`git_pkt_parse_line` to set the out-pointer to `NULL` itself when
it encounters such an empty packet. Like this it is guaranteed
that there will be no invalid memory references to free'd
pointers.
As such, the issue has been fixed such that `git_pkt_parse_line`
always sets the packet out pointer to `NULL` when an empty packet
has been received and callers check for this condition, skipping
such packets.
When adding a new entry to an existing index via `git_index_read_index`,
be sure to remove the tree cache entry for that new path. This will
mark all parent trees as dirty.
Clear any error state upon each iteration. If one of the iterations
ends (with an error of `GIT_ITEROVER`) we need to reset that error to 0,
lest we stop the whole process prematurely.
It looks like we're getting the operation and not doing anything
with it, when in fact we are asserting that it's not null. Simply
assert that we are within the operation boundary instead of using
the `git_array_get` macro to do this for us.
Parse values up to and including `\377` (`0xff`) when unquoting.
Print octal values as an unsigned char when quoting, lest `printf`
think we're talking about negatives.
`oid_strlen` has meant one more than the length of the string.
This is mighty confusing. Make it mean only the string length!
Whomsoever needs to allocate a buffer to hold a string can null
terminate it like normal.
When a text file is added or deleted, use the file names from the
`diff --git` header instead of the `---` or `+++` lines. This is
for compatibility with git.
Now that `git_diff_delta` data can be produced by reading patch
file data, which may have an abbreviated oid, allow consumers to
know that the id is abbreviated.
Patches can now come from a variety of sources - either internally
generated (from diffing two commits) or as the results of parsing
some external data.
When we are provided some input buffer (with a length) to inflate,
and it contains more data than simply the deflated data, fail.
zlib will helpfully tell us when it is done reading (via Z_STREAM_END),
so if there is data leftover in the input buffer, fail lest we
continually try to inflate it.
Handle the application of binary patches. Include tests that
produce a binary patch (an in-memory `git_patch` object),
then enusre that the patch applies correctly.
Move the delta application functions into `delta.c`, next to the
similar delta creation functions. Make the `git__delta_apply`
functions adhere to other naming and parameter style within the
library.
When we want to remove the file, use the basename as the name of the
entry to remove, instead of the full one, which includes the directories
we've inserted into the stack.
Instead of going through the usual steps of reading a tree recursively
into an index, modifying it and writing it back out as a tree, introduce
a function to perform simple updates more efficiently.
`git_tree_create_updated` avoids reading trees which are not modified
and supports upsert and delete operations. It is not as versatile as
modifying the index, but it makes some common operations much more
efficient.
When calling `git_commit_create` with an empty array of `parents` and `parent_count == 0`
the call will segfault at https://github.com/libgit2/libgit2/blob/master/src/commit.c#L107
when it's trying to compare `current_id` to a null parent oid.
This just puts in a check to stop that segfault.
When determining diffs between two iterators we may need to
recurse into an unmatched directory for the "new" iterator when
it is either a prefix to the current item of the "old" iterator
or when untracked/ignored changes are requested by the user and
the directory is untracked/ignored.
When advancing into the directory and no files are found, we will
get back `GIT_ENOTFOUND`. If so, we simply skip the directory,
handling resulting unmatched old items in the next iteration. The
other case of `iterator_advance_into` returning either
`GIT_NOERROR` or any other error but `GIT_ENOTFOUND` will be
handled by the caller, which will now either compare the first
directory entry of the "new" iterator in case of `GIT_ENOERROR`
or abort on other cases.
Improve readability of the code to make the above logic more
clear.
We compute offsets by executing `off |= (*delta++ << 24)` for
multiple constants, where `off` is of type `size_t` and `delta`
is of type `unsigned char`. The usual arithmetic conversions (see
ISO C89 §3.2.1.5 "Usual arithmetic conversions") kick in here,
causing us to promote both operands to `int` and then extending
the result to an `unsigned long` when OR'ing it with `off`.
The integer promotion to `int` may result in wrong size
calculations for big values.
Fix the issue by making the constants `unsigned long`, causing both
operands to be promoted to `unsigned long`.
An object's size is computed by reading the object header's size
field until the most significant bit is not set anymore. To get
the total size, we increase the shift on each iteration and add
the shifted value to the total size.
We read the current value into a variable of type `unsigned
char`, from which we then take all bits except the most
significant bit and shift the result. We will end up with a
maximum shift of 60, but this exceeds the width of the value's
type, resulting in undefined behavior.
Fix the issue by instead reading the values into a variable of
type `unsigned long`, which matches the required width. This is
equivalent to git.git, which uses an `unsigned long` as well.
When `git_repository__cvar` fails we may end up with a
`ignorecase` value of `-1`. As we subsequently check if
`ignorecase` is non-zero, we may end up reporting that data
should be removed when in fact it should not.
Err on the safer side and set `ignorecase = 0` when
`git_repository__cvar` fails.
The `merge_file__xdiff` function checks if either `ours` or
`theirs` is `NULL`. The function is to be called with existing
files, though, and in fact already unconditionally dereferences
both pointers.
Remove the unnecessary check to silence warnings.
When we read the header, we want to know the size and type of the
object. We're currently inflating the full delta in order to read the
first few bytes. This can mean hundreds of kB needlessly inflated for
large objects.
Instead use a packfile stream to read just enough so we can read the two
varints in the header and avoid inflating most of the delta.
Differentiate between the ref_name used to create an annotated_commit
(that can subsequently be used to look up the reference) and the
description that we resolved this with (which _cannot_ be looked up).
The description is used for things like reflogs (and may be a ref name,
and ID something that we revparsed to get here), while the ref name must
actually be a reference name, and is used for things like rebase to
return to the initial branch.
openssl_read should return -1 in case of error.
SSL_read returns values <= 0 in case of error.
A return value of 0 can lead to an infinite loop, so the return value
of ssl_set_error will be returned if SSL_read is not successful (analog
to openssl_write).
While no extra header fields are defined for tags, git accepts them by
ignoring them and continuing the search for the message. There are a few
tags like this in the wild which git parses just fine, so we should do
the same.
When `init`ing a rebase from a detached HEAD, be sure to remember
that we were in a detached HEAD state so that we can correctly
`abort` the object that we just created.
In order to match the star-star, we disable the flag that's looking for
a single path element, but that leads to searching for the pattern in
the middle of elements in the input string.
Mark when we're handing a star-star so we jump over the elements in our
attempt to match the part of the pattern that comes after the star-star.
While here, tighten up the check so we don't allow invalid rules
through.
When we're dealing with proxy addresses, we only want a hostname and
port, and the user would not provide a path, so make it optional so we
can use this same function to parse git as well as proxy URLs.
If we cannot dwim the input, set the error message to be explicit about
that. Otherwise we leave the error for the last failed lookup, which
can be rather unexpected as it mentions a remote when the user thought
they were trying to look up a branch.
Allow callers to specify a start path with a trailing slash to match
a submodule, instead of just a directory. This is for some legacy
behavior that's sort of dumb, but there it is.
If we're looking for a symlink, realpath will give us the resolved path,
which is not what we're after, but a canonicalized version of the path
the user asked for.
The code initializing the merge driver registry accidentally
forgot a `goto done` in case of an error. Because of this the
next line, which registers the global shutdown callback for the
merge drivers, is only called when an error occured.
Fix this by adding the missing `goto done`. This fixes some
memory leaks when the global state is shut down.
The xdl_prepare_env() function may initialise an xdlclassifier_t
data structure via xdl_init_classifier(), which allocates memory
to several fields, for example 'rchash', 'rcrecs' and 'ncha'.
If this function later exits due to the failure of xdl_optimize_ctxs(),
then this xdlclassifier_t structure, and the memory allocated to it,
is not cleaned up.
In order to fix the memory leak, insert a call to xdl_free_classifier()
before returning.
This patch was originally written by Ramsay Jones (see commit
87f16258367a3b9a62663b11f898a4a6f3c19d31 in git.git).
Commit 307ab20b3 ("xdiff: PATIENCE/HISTOGRAM are not independent option
bits", 19-02-2012) introduced the XDF_DIFF_ALG() macro to access the
flag bits used to represent the diff algorithm requested. In addition,
code which had used explicit manipulation of the flag bits was changed
to use the macros.
However, one example of direct manipulation remains. Update this code to
use the XDF_DIFF_ALG() macro.
This patch was originally written by Ramsay Jones (see commit
5cd6978a9cfef58de061a9525f3678ade479564d in git.git).
If we hit the EOF while trying to write a new value, it may be that
we're already in the section that we were looking for. If so, do not
write a (duplicate) section header, just write the value.
Ensure that we have hit the end of iteration; previously we tested
that we saw all the values that we expected to see. We did not
then ensure that we were at the end of the iteration (and that there
were subsequently values in the iteration that we did *not* expect.)
Drop some of the layers of indirection between the workdir and the
filesystem iterators. This makes the code a little bit easier to
follow, and reduces the number of unnecessary allocations a bit as
well. (Prior to this, when we filter entries, we would allocate them,
filter them and then free them; now we do the filtering before
allocation.)
Also, rename `git_iterator_advance_over_with_status` to just
`git_iterator_advance_over`. Mostly because it's a fucking long-ass
function name otherwise.
Many code paths in checkout need the final, full on-disk path of the
file they're writing. (No surprise). However, they all munge the
`data->path` buffer themselves to get there. Provide a nice helper
method for them.
Plus, drop the use `git_iterator_current_workdir_path` which does the
same thing but different. Checkout is the only caller of this silly
function, which lets us remove it.
Refactored the tree iterator to never recurse; simply process the
next entry in order in `advance`. Additionally, reduce the number of
allocations and sorting as much as possible to provide a ~30% speedup
on case-sensitive iteration. (The gains for case-insensitive iteration
are less majestic.)
Disambiguate the reset and reset_range functions. Now reset_range
with a NULL path will clear the start or end; reset will leave the
existing start and end unchanged.
The callback mechanism makes it awkward to write data from an IO
source; move to `_fromstream()` which lets the caller remain in control,
in the same vein as we prefer iterators over foreach callbacks.
The pair of `git_blob_create_frombuffer()` and
`git_blob_create_frombuffer_commit()` is meant to replace
`git_blob_create_fromchunks()` by providing a way for a user to write a
new blob when they want filtering or they do not know the size.
This approach allows the caller to retain control over when to add data
to this buffer and a more natural fit into higher-level language's own
stream abstractions instead of having to handle IO wait in the callback.
The in-memory buffer size of 2MB is chosen somewhat arbitrarily to be a
round multiple of usual page sizes and a value where most blobs seem
likely to be either going to be way below or way over that size. It's
also a round number of pages.
This implementation re-uses the helper we have from `_fromchunks()` so
we end up writing everything to disk, but hopefully more efficiently
than with a default filebuf. A later optimisation can be to avoid
writing the in-memory contents to disk, with some extra complexity.
Allow setting the buffer size on open in order to use this data
structure more generally as a spill buffer, with larger buffer sizes for
specific use-cases.
This special-casing ignores that we might have a locked file, so the
hashtable does not represent the contents of the file we want to
write. This causes multivar writes to overwrite entries instead of add
to them when under lock.
There is no need for this as the normal code-path will write to the file
just fine, so simply get rid of it.
Take advantage of the constant size of tree-owned arrays and store them
in an array instead of a pool. This still lets us free them all at once
but lets the system allocator do the work of fitting them in.
Since the `apply` callback can defer, the `check` callback is not
necessary. Removing the `check` callback further makes the `payload`
unnecessary along with the `cleanup` callback.
Consumers can now register custom merged drivers with
`git_merge_driver_register`. This allows consumers to support the
merge drivers, as configured in `.gitattributes`. Consumers will be
asked to perform the file-level merge when a custom driver is
configured.
The function to extract signatures suffers from a similar bug to the
header field finding one by having an unecessary line feed check as a
break condition of its loop.
Fix that and add a test for this single-line signature situation.
While often similar, these are not the same on Windows. We want to use the page
size on Windows for the pools, but for mmap we need to use the allocation
granularity as the alignment.
On the other platforms these values remain the same.
This ensures that when using OpenSSL a safe default set of ciphers
is selected. This is done so that the client communicates securely
and we don't accidentally enable unsafe ciphers like RC4, or even
worse some old export ciphers.
Implements the first part of https://github.com/libgit2/libgit2/issues/3682
Callers of `git_config__cvar` already handle the case where the
function returns an error due to a failed configuration variable
lookup, but we are actually swallowing errors when calling
`git_config__lookup_entry` inside of the function.
Fix this by returning early when `git_config__lookup_entry`
returns an error. As we call `git_config__lookup_entry` with
`no_errors == false` which leads us to call `get_entry` with
`GET_NO_MISSING` we will not return early when the lookup fails
due to a missing entry. Like this we are still able to set the
default value of the cvar and exit successfully.
When writing to a file with locking not check if writing the
locked file actually succeeds. Fix the issue by returning error
code and message when writing fails.
Accessing the current values map is handled through the
`refcounder_strmap_take` function, which first acquires a mutex
before accessing its values. While this assures everybody is
trying to access the values with the mutex only we do not check
if the locking actually succeeds.
Fix the issue by checking if acquiring the lock succeeds and
returning `NULL` if we encounter an error. Adjust callers.
When normalizing options we try to look up HEAD's OID. While this
action may fail in malformed repositories we never check the
return value of the function.
Fix the issue by converting `normalize_options` to actually
return an error and handle the error in `git_blame_file`.
We usually check entries returned by `git_sortedcache_entry` for
NULL pointers. As we have a write lock in `packed_write`, though,
it really should not happen that the function returns NULL.
Assert that ref is not NULL to silence a Coverity warning.
When the user passes in a diff which has no repository associated
we may call `git_config__get_int_force` with a NULL-pointer
configuration. Even though `git_config__get_int_force` is
designed to swallow errors, it is not intended to be called with
a NULL pointer configuration.
Fix the issue by only calling `git_config__get_int_force` only
when configuration could be retrieved from the repository.
In C89 it is undefined behavior to pass `NULL` pointers to
`strncmp` and later on in C99 it has been explicitly stated that
functions with an argument declared as `size_t nmemb` specifying
the array length shall always have valid parameters, no matter if
`nmemb` is 0 or not (see ISO 9899 §7.21.1.2).
The function `str_equal_no_trailing_slash` always passes its
parameters to `strncmp` if their lengths match. This means if one
parameter is `NULL` and the other one either `NULL` or a string
with length 0 we will pass the pointers to `strncmp` and cause
undefined behavior.
Fix this by explicitly handling the case when both lengths are 0.
When computing a short OID we do this by first copying the
leading parts into the new OID structure and then setting the
trailing part to zero. In the case of the desired length being
`GIT_OID_HEXSZ - 1` we will call `memset` with an out of bounds
pointer and a length of 0. While this seems to cause no problems
for common platforms the C89 standard does not explicitly state
that calling `memset` with an out of bounds pointer and
length of 0 is valid.
Fix the potential issue by using the newly introduced
`git_oid__cpy_prefix` function.
When parsing a section header we expect something along the
format of '[section "subsection"]'. When a section is
mal-formated and is entirely missing its quotation marks we catch
this case by observing that `strchr(line, '"') - strrchr(line,
'"') = NULL - NULL = 0` and error out. Unfortunately, the error
message is misleading though, as we state that we are missing the
closing quotation mark while we in fact miss both quotation
marks.
Improve the error message by explicitly checking if the first
quotation mark could be found and, if not, stating that quotation
marks are completely missing.
