Upstream symbolic link support on Windows from Git-for-Windows.
* js/symlink-windows:
mingw: special-case index entries for symlinks with buggy size
mingw: emulate `stat()` a little more faithfully
mingw: try to create symlinks without elevated permissions
mingw: add support for symlinks to directories
mingw: implement basic `symlink()` functionality (file symlinks only)
mingw: implement `readlink()`
mingw: allow `mingw_chdir()` to change to symlink-resolved directories
mingw: support renaming symlinks
mingw: handle symlinks to directories in `mingw_unlink()`
mingw: add symlink-specific error codes
mingw: change default of `core.symlinks` to false
mingw: factor out the retry logic
mingw: compute the correct size for symlinks in `mingw_lstat()`
mingw: teach dirent about symlinks
mingw: let `mingw_lstat()` error early upon problems with reparse points
mingw: drop the separate `do_lstat()` function
mingw: implement `stat()` with symlink support
mingw: don't call `GetFileAttributes()` twice in `mingw_lstat()`
Further preparation to upstream symbolic link support on Windows.
* js/prep-symlink-windows:
trim_last_path_component(): avoid hard-coding the directory separator
strbuf_readlink(): support link targets that exceed 2*PATH_MAX
strbuf_readlink(): avoid calling `readlink()` twice in corner-cases
init: do parse _all_ core.* settings early
mingw: do resolve symlinks in `getcwd()`
The final clean-up phase of the diff output could turn the result of
histogram diff algorithm suboptimal, which has been corrected.
Comments?
* yc/histogram-hunk-shift-fix:
xdiff: re-diff shifted change groups when using histogram algorithm
Introduce a more robust way to parse a decimal integer stored in a
piece of memory that is not necessarily terminated with NUL (which
Asan strict-string-check complains even when use of strtol() is
safe due to varified existence of whitespace after the digits).
* jk/parse-int:
fsck: use parse_unsigned_from_buf() for parsing timestamp
cache-tree: use parse_int_from_buf()
parse: add functions for parsing from non-string buffers
parse: prefer bool to int for boolean returns
The "-z" and "--max-depth" documentation (and implementation of
"-z") in the "git last-modified" command have been updated.
* tc/last-modified-options-cleanup:
fixup! last-modified: document option --max-depth
last-modified: document how depth is handled better
last-modified: document option --max-depth
last-modified: handle and document NUL termination
A mechanism to specify what reference backend to use and store
references in which directory is introduced, which would likely to
be useful during ref migration.
Comments?
* kn/ref-location:
refs: add GIT_REF_URI to specify reference backend and directory
refs: support obtaining ref_store for given dir
The command line completion script (in contrib/) learned to
complete "git -<TAB>" to give single-letter options like "-C".
* wm/complete-git-short-opts:
completion: complete "git -<TAB>" with short options
Avoid local submodule repository directory paths overlapping with
each other by encoding submodule names before using them as path
components.
Comments?
* ar/submodule-gitdir-tweak:
submodule: detect conflicts with existing gitdir configs
submodule: hash the submodule name for the gitdir path
submodule: fix case-folding gitdir filesystem collisions
submodule--helper: fix filesystem collisions by encoding gitdir paths
builtin/credential-store: move is_rfc3986_unreserved to url.[ch]
submodule--helper: add gitdir migration command
submodule: allow runtime enabling extensions.submodulePathConfig
submodule: introduce extensions.submodulePathConfig
builtin/submodule--helper: add gitdir command
submodule: always validate gitdirs inside submodule_name_to_gitdir
submodule--helper: use submodule_name_to_gitdir in add_submodule
The packfile_store data structure is moved from object store to odb
source.
* ps/packfile-store-in-odb-source:
packfile: move MIDX into packfile store
packfile: refactor `find_pack_entry()` to work on the packfile store
packfile: inline `find_kept_pack_entry()`
packfile: only prepare owning store in `packfile_store_prepare()`
packfile: only prepare owning store in `packfile_store_get_packs()`
packfile: move packfile store into object source
packfile: refactor misleading code when unusing pack windows
packfile: refactor kept-pack cache to work with packfile stores
packfile: pass source to `prepare_pack()`
packfile: create store via its owning source
The split command in "git subtree" (in contrib/) has been taught to
deal better with rebased history.
* cs/rebased-subtree-split:
contrib/subtree: detect rewritten subtree commits
"git fsck" used inconsistent set of refs to show a confused
warning, which has been corrected.
* en/fsck-snapshot-ref-state:
fsck: snapshot default refs before object walk
"git patch-id" documentation updates.
* kh/doc-patch-id:
doc: patch-id: --verbatim locks in --stable
doc: patch-id: spell out the git-diff-tree(1) form
doc: patch-id: use definite article for the result
patch-id: use “patch ID” throughout
doc: patch-id: capitalize Git version
doc: patch-id: don’t use semicolon between bullet points
Update a FAQ entry on synching two separate repositories using the
"git stash export/import" recently introduced.
* bc/doc-stash-import-export:
gitfaq: document using stash import/export to sync working tree
Import newer version of "clar", unit testing framework.
* ps/clar-integers:
gitattributes: disable blank-at-eof errors for clar test expectations
t/unit-tests: demonstrate use of integer comparison assertions
t/unit-tests: update clar to 39f11fe
Improve the error message when a bad argument is given to the
`--onto` option of "git replay". Test coverage of "git replay" has
been improved.
* kh/replay-invalid-onto-advance:
t3650: add more regression tests for failure conditions
replay: die if we cannot parse object
replay: improve code comment and die message
replay: die descriptively when invalid commit-ish is given
replay: find *onto only after testing for ref name
replay: remove dead code and rearrange
Miscellaneous fixes on object database layer.
* ps/odb-misc-fixes:
odb: properly close sources before freeing them
builtin/gc: fix condition for whether to write commit graphs
Code clean-up, unifying various hand-rolled "list of commit
objects" and use the commit_stack API.
* rs/commit-stack:
commit-reach: use commit_stack
commit-graph: use commit_stack
commit: add commit_stack_grow()
shallow: use commit_stack
pack-bitmap-write: use commit_stack
commit: add commit_stack_init()
test-reach: use commit_stack
remote: use commit_stack for src_commits
remote: use commit_stack for sent_tips
remote: use commit_stack for local_commits
name-rev: use commit_stack
midx: use commit_stack
log: use commit_stack
revision: export commit_stack
Diagnose invalid bundle-URI that lack the URI entry, instead of
crashing.
* sb/bundle-uri-without-uri:
bundle-uri: validate that bundle entries have a uri
More doc style updates.
* ja/doc-synopsis-style-more:
doc: convert git-remote to synopsis style
doc: convert git stage to use synopsis block
doc: convert git-status tables to AsciiDoc format
doc: convert git-status to synopsis style
doc: fix t0450-txt-doc-vs-help to select only first synopsis block
git subtree split --prefix P
detects splits that are outside of path prefix `P` and prunes
them from history graph processing. This improves the performance
of repeated `split --rejoin` with many different prefixes.
Both before and after 83f9dad7d6 (contrib/subtree: fix split with
squashed subtrees, 2025-09-09), the pruning logic does not detect
**rebased** or **cherry-picked** git-subtree commits. If `split`
encounters any of these commits, the split output may have
incomplete history.
All commits authored by
git subtree merge [--squash] --prefix Q
have a first or second parent that has *only* subtree commits
as ancestors. When splitting a completely different path `P/`,
it is safe to ignore:
1. the merged tree
2. the subtree parent
3. *all* of that parent's ancestry, which applies only to
path `Q/` and not `P/`.
But this relationship no longer holds if the git-subtree commit
is rebased or otherwise reauthored. After a rebase, the former
git-subtree commit will have other unrelated commits as ancestors.
Ignoring these commits may exclude the history of `P/`,
leading to incomplete `subtree split` output.
The pruning logic relies solely on the `git-subtree-*:` trailers
to detect git-subtree commits, which it blindly accepts without
further validation. The split logic also takes its time about
being wrong: `cmd_split()` execs a `git show` for *every* commit
in the split range… twice. This is inefficient in a shell script.
Add a "reality check" to ignore rebased or rewritten commits:
* Rewrites of non-merge commits cannot be detected, so the new
detector no longer looks for them.
* Merges carry a `git-subtree-mainline:` trailer with the hash of
the **first parent**. If this hash differs, or if the "merge"
commit no longer has multiple parents, a rewrite has occurred.
To increase speed, package this logic in a new method,
`find_other_splits()`. Perform the check up-front by iterating
over a single `git log`. Add ignored subtrees to:
1. the `notree` cache, which excludes them from the `split` history
2. a `prune` negative refs list. The negative refs prevent
recursing into other subtrees. Since there are potentially a
*lot* of these, cache them on disk and use rev-list's
`--stdin` mode.
Reported-by: George <george@mail.dietrich.pub>
Signed-off-by: Colin Stagner <ask+git@howdoi.land>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In https://github.com/git-for-windows/git/pull/2637, we fixed a bug
where symbolic links' target path sizes were recorded incorrectly in the
index. The downside of this fix was that every user with tracked
symbolic links in their checkouts would see them as modified in `git
status`, but not in `git diff`, and only a `git add <path>` (or `git add
-u`) would "fix" this.
Let's do better than that: we can detect that situation and simply
pretend that a symbolic link with a known bad size (or a size that just
happens to be that bad size, a _very_ unlikely scenario because it would
overflow our buffers due to the trailing NUL byte) means that it needs
to be re-checked as if we had just checked it out.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When creating directories via `safe_create_leading_directories()`, we
might encounter an already-existing directory which is not
readable by the current user. To handle that situation, Git's code calls
`stat()` to determine whether we're looking at a directory.
In such a case, `CreateFile()` will fail, though, no matter what, and
consequently `mingw_stat()` will fail, too. But POSIX semantics seem to
still allow `stat()` to go forward.
So let's call `mingw_lstat()` to the rescue if we fail to get a file
handle due to denied permission in `mingw_stat()`, and fill the stat
info that way.
We need to be careful to not allow this to go forward in case that we're
looking at a symbolic link: to resolve the link, we would still have to
create a file handle, and we just found out that we cannot. Therefore,
`stat()` still needs to fail with `EACCES` in that case.
This fixes https://github.com/git-for-windows/git/issues/2531.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As of Windows 10 Build 14972 in Developer Mode, a new flag is supported
by `CreateSymbolicLink()` to create symbolic links even when running
outside of an elevated session (which was previously required).
This new flag is called `SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE`
and has the numeric value 0x02.
Previous Windows 10 versions will not understand that flag and return
an `ERROR_INVALID_PARAMETER`, therefore we have to be careful to try
passing that flag only when the build number indicates that it is
supported.
For more information about the new flag, see this blog post:
https://blogs.windows.com/buildingapps/2016/12/02/symlinks-windows-10/
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Symlinks on Windows have a flag that indicates whether the target is a
file or a directory. Symlinks of wrong type simply don't work. This even
affects core Win32 APIs (e.g. `DeleteFile()` refuses to delete directory
symlinks).
However, `CreateFile()` with FILE_FLAG_BACKUP_SEMANTICS does work. Check
the target type by first creating a tentative file symlink, opening it,
and checking the type of the resulting handle. If it is a directory,
recreate the symlink with the directory flag set.
It is possible to create symlinks before the target exists (or in case
of symlinks to symlinks: before the target type is known). If this
happens, create a tentative file symlink and postpone the directory
decision: keep a list of phantom symlinks to be processed whenever a new
directory is created in `mingw_mkdir()`.
Limitations: This algorithm may fail if a link target changes from file
to directory or vice versa, or if the target directory is created in
another process. It's the best Git can do, though.
Signed-off-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement `symlink()`. This implementation always creates _file_
symlinks (remember: Windows discerns between symlinks pointing to
directories and those pointing to files). Support for directory symlinks
will be added in a subseqeuent commit.
This implementation fails with `ENOSYS` if symlinks are disabled or
unsupported.
Signed-off-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement `readlink()` by reading NTFS reparse points via the
`read_reparse_point()` function that was introduced earlier to determine
the length of symlink targets. Works for symlinks and directory
junctions.
Signed-off-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If symlinks are enabled, resolve all symlinks when changing directories,
as required by POSIX.
Note: Git's `real_path()` function bases its link resolution algorithm
on this property of `chdir()`. Unfortunately, the current directory on
Windows is limited to only MAX_PATH (260) characters. Therefore using
symlinks and long paths in combination may be problematic.
Signed-off-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Older MSVCRT's `_wrename()` function cannot rename symlinks over
existing files: it returns success without doing anything. Newer
MSVCR*.dll versions probably do not share this problem: according to CRT
sources, they just call `MoveFileEx()` with the `MOVEFILE_COPY_ALLOWED`
flag.
Avoid the `_wrename()` call, and go with directly calling
`MoveFileEx()`, with proper error handling of course.
Signed-off-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `_wunlink()` and `DeleteFileW()` functions refuse to delete symlinks
to directories on Windows; The error code would be `ERROR_ACCESS_DENIED`
in that case. Take that error code as an indicator that we need to try
`_wrmdir()` as well. In the best case, it will remove a symlink. In the
worst case, it will fail with the same error code again.
Signed-off-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The Win32 API calls do not set `errno`; Instead, error codes for failed
operations must be obtained via the `GetLastError()` function. Git would
not know what to do with those error values, though, which is why Git's
Windows compatibility layer translates them to `errno` values.
Let's handle a couple of symlink-related error codes that will become
relevant with the upcoming support for symlinks on Windows.
Signed-off-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Symlinks on Windows don't work the same way as on Unix systems. For
example, there are different types of symlinks for directories and
files, and unless using a recent-ish Windows version in Developer Mode,
creating symlinks requires administrative privileges.
By default, disable symlink support on Windows. That is, users
explicitly have to enable it with `git config [--system|--global]
core.symlinks true`; For convenience, `git init` (and `git clone`)
will perform a test whether the current setup allows creating symlinks
and will configure that setting in the repository config.
The test suite ignores system / global config files. Allow
testing *with* symlink support by checking if native symlinks are
enabled in MSYS2 (via setting the special environment variable
`MSYS=winsymlinks:nativestrict` to ask the MSYS2 runtime to enable
creating symlinks).
Note: This assumes that Git's test suite is run in MSYS2's Bash, which
is true for the time being (an experiment to switch to BusyBox-w32
failed due to the experimental nature of BusyBox-w32).
Signed-off-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In several places, Git's Windows-specific code follows the pattern where
it tries to perform an operation, and retries several times when that
operation fails, sleeping an increasing amount of time, before finally
giving up and asking the user whether to rety (after, say, closing an
editor that held a handle to a file, preventing the operation from
succeeding).
This logic is a bit hard to use, and inconsistent:
`mingw_unlink()` and `mingw_rmdir()` duplicate the code to retry,
and both of them do so incompletely. They also do not restore `errno` if the
user answers 'no'.
Introduce a `retry_ask_yes_no()` helper function that handles retry with
small delay, asking the user, and restoring `errno`.
Note that in `mingw_unlink()`, we include the `_wchmod()` call in the
retry loop (which may fail if the file is locked exclusively).
In `mingw_rmdir()`, we include special error handling in the retry loop.
Signed-off-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
POSIX specifies that upon successful return from `lstat()`: "the
value of the st_size member shall be set to the length of the pathname
contained in the symbolic link not including any terminating null byte".
Git typically doesn't trust the `stat.st_size` member of symlinks (e.g.
see `strbuf_readlink()`). Therefore, it is tempting to save on the extra
overhead of opening and reading the reparse point merely to calculate
the exact size of the link target.
This is, in fact, what Git for Windows did, from May 2015 to May 2020.
At least almost: some functions take shortcuts if `st_size` is 0 (e.g.
`diff_populate_filespec()`), hence Git for Windows hard-coded the length
of all symlinks to MAX_PATH.
This did cause problems, though, specifically in Git repositories
that were also accessed by Git for Cygwin or Git for WSL. For example,
doing `git reset --hard` using Git for Windows would update the size of
symlinks in the index to be MAX_PATH; at a later time Git for Cygwin
or Git for WSL would find that symlinks have changed size during `git
status` and update the index. And then Git for Windows would think that
the index needs to be updated. Even if the symlinks did not, in fact,
change. To avoid that, the correct size must be determined.
Signed-off-by: Bill Zissimopoulos <billziss@navimatics.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the `S_IFLNK` detection to `file_attr_to_st_mode()`.
Implement `DT_LNK` detection in dirent.c's `readdir()` function.
Signed-off-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When obtaining lstat information for reparse points, we need to call
`FindFirstFile()` in addition to `GetFileInformationEx()` to obtain
the type of the reparse point (symlink, mount point etc.). However,
currently there is no error handling whatsoever if `FindFirstFile()`
fails.
Call `FindFirstFile()` before modifying the `stat *buf` output parameter
and error out if the call fails.
Note: The `FindFirstFile()` return value includes all the data
that we get from `GetFileAttributesEx()`, so we could replace
`GetFileAttributesEx()` with `FindFirstFile()`. We don't do that because
`GetFileAttributesEx()` is about twice as fast for single files. I.e.
we only pay the extra cost of calling `FindFirstFile()` in the rare case
that we encounter a reparse point.
Please also note that the indentation the remaining reparse point
code changed, and hence the best way to look at this diff is with
`--color-moved -w`. That code was _not_ moved because a subsequent
commit will move it to an altogether different function, anyway.
Signed-off-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
