Commit Graph

129211 Commits

Author SHA1 Message Date
Johannes Schindelin
7cdbfa1f44 t5532: workaround for BusyBox on Windows
While it may seem super convenient to some old Unix hands to simpy
require Perl to be available when running the test suite, this is a
major hassle on Windows, where we want to verify that Perl is not,
actually, required in a NO_PERL build.

As a super ugly workaround, we "install" a script into /usr/bin/perl
reading like this:

	#!/bin/sh

	# We'd much rather avoid requiring Perl altogether when testing
	# an installed Git. Oh well, that's why we cannot have nice
	# things.
	exec c:/git-sdk-64/usr/bin/perl.exe "$@"

The problem with that is that BusyBox assumes that the #! line in a
script refers to an executable, not to a script. So when it encounters
the line #!/usr/bin/perl in t5532's proxy-get-cmd, it barfs.

Let's help this situation by simply executing the Perl script with the
"interpreter" specified explicitly.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:14 -08:00
Neeraj Singh
ec09abd426 update-index: use the bulk-checkin infrastructure
The update-index functionality is used internally by 'git stash push' to
setup the internal stashed commit.

This change enables bulk-checkin for update-index infrastructure to
speed up adding new objects to the object database by leveraging the
pack functionality and the new bulk-fsync functionality.

There is some risk with this change, since under batch fsync, the object
files will not be available until the update-index is entirely complete.
This usage is unlikely, since any tool invoking update-index and
expecting to see objects would have to synchronize with the update-index
process after passing it a file path.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-24 11:15:14 -08:00
Johannes Schindelin
380de44cd6 t5003: use binary file from t/lib-diff/
At some stage, t5003-archive-zip wants to add a file that is not ASCII.
To that end, it uses /bin/sh. But that file may actually not exist (it
is too easy to forget that not all the world is Unix/Linux...)! Besides,
we already have perfectly fine binary files intended for use solely by
the tests. So let's use one of them instead.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:14 -08:00
Neeraj Singh
0ea7bafa77 core.fsyncobjectfiles: add windows support for batch mode
This commit adds a win32 implementation for fsync_no_flush that is
called git_fsync. The 'NtFlushBuffersFileEx' function being called is
available since Windows 8. If the function is not available, we
return -1 and Git falls back to doing a full fsync.

The operating system is told to flush data only without a hardware
flush primitive. A later full fsync will cause the metadata log
to be flushed and then the disk cache to be flushed on NTFS and
ReFS. Other filesystems will treat this as a full flush operation.

I added a new file here for this system call so as not to conflict with
downstream changes in the git-for-windows repository related to fscache.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-24 11:15:14 -08:00
Johannes Schindelin
d3e8cf9ea2 t0021: use Windows path when appropriate
Since c6b0831c9c (docs: warn about possible '=' in clean/smudge filter
process values, 2016-12-03), t0021 writes out a file with quotes in its
name, and MSYS2's path conversion heuristics mistakes that to mean that
we are not talking about a path here.

Therefore, we need to use Windows paths, as the test-helper is a Win32
program that would otherwise have no idea where to look for the file.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:14 -08:00
Neeraj Singh
c1f4fba705 core.fsyncobjectfiles: batched disk flushes
When adding many objects to a repo with core.fsyncObjectFiles set to
true, the cost of fsync'ing each object file can become prohibitive.

One major source of the cost of fsync is the implied flush of the
hardware writeback cache within the disk drive. Fortunately, Windows,
and macOS offer mechanisms to write data from the filesystem page cache
without initiating a hardware flush. Linux has the sync_file_range API,
which issues a pagecache writeback request reliably after version 5.2.

This patch introduces a new 'core.fsyncObjectFiles = batch' option that
batches up hardware flushes. It hooks into the bulk-checkin plugging and
unplugging functionality and takes advantage of tmp-objdir.

When the new mode is enabled do the following for each new object:
1. Create the object in a tmp-objdir.
2. Issue a pagecache writeback request and wait for it to complete.

At the end of the entire transaction when unplugging bulk checkin:
1. Issue an fsync against a dummy file to flush the hardware writeback
   cache, which should by now have processed the tmp-objdir writes.
2. Rename all of the tmp-objdir files to their final names.
3. When updating the index and/or refs, we assume that Git will issue
   another fsync internal to that operation. This is not the case today,
   but may be a good extension to those components.

On a filesystem with a singular journal that is updated during name
operations (e.g. create, link, rename, etc), such as NTFS, HFS+, or XFS
we would expect the fsync to trigger a journal writeout so that this
sequence is enough to ensure that the user's data is durable by the time
the git command returns.

This change also updates the macOS code to trigger a real hardware flush
via fnctl(fd, F_FULLFSYNC) when fsync_or_die is called. Previously, on
macOS there was no guarantee of durability since a simple fsync(2) call
does not flush any hardware caches.

_Performance numbers_:

Linux - Hyper-V VM running Kernel 5.11 (Ubuntu 20.04) on a fast SSD.
Mac - macOS 11.5.1 running on a Mac mini on a 1TB Apple SSD.
Windows - Same host as Linux, a preview version of Windows 11.
	  This number is from a patch later in the series.

Adding 500 files to the repo with 'git add' Times reported in seconds.

core.fsyncObjectFiles | Linux | Mac   | Windows
----------------------|-------|-------|--------
                false | 0.06  |  0.35 | 0.61
                true  | 1.88  | 11.18 | 2.47
                batch | 0.15  |  0.41 | 1.53

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-24 11:15:14 -08:00
Johannes Schindelin
bdc0b99f4d test-lib: add BUSYBOX prerequisite
When running with BusyBox, we will want to avoid calling executables on
the PATH that are implemented in BusyBox itself.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:14 -08:00
Neeraj Singh
29ee906ca2 bulk-checkin: rename 'state' variable and separate 'plugged' boolean
Preparation for adding bulk-fsync to the bulk-checkin.c infrastructure.

* Rename 'state' variable to 'bulk_checkin_state', since we will later
  be adding 'bulk_fsync_state'.  This also makes the variable easier to
  find in the debugger, since the name is more unique.

* Move the 'plugged' data member of 'bulk_checkin_state' into a separate
  static variable. Doing this avoids resetting the variable in
  finish_bulk_checkin when zeroing the 'bulk_checkin_state'. As-is, we
  seem to unintentionally disable the plugging functionality the first
  time a new packfile must be created due to packfile size limits. While
  disabling the plugging state only results in suboptimal behavior for
  the current code, it would be fatal for the bulk-fsync functionality
  later in this patch series.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-24 11:15:14 -08:00
Johannes Schindelin
131ad234e2 tests (mingw): remove Bash-specific pwd option
The -W option is only understood by MSYS2 Bash's pwd command. We already
make sure to override `pwd` by `builtin pwd -W` for MINGW, so let's not
double the effort here.

This will also help when switching the shell to another one (such as
BusyBox' ash) whose pwd does *not* understand the -W option.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:14 -08:00
Johannes Schindelin
5f59fd69e0 mingw: only use Bash-ism builtin pwd -W when available
Traditionally, Git for Windows' SDK uses Bash as its default shell.
However, other Unix shells are available, too. Most notably, the Win32
port of BusyBox comes with `ash` whose `pwd` command already prints
Windows paths as Git for Windows wants them, while there is not even a
`builtin` command.

Therefore, let's be careful not to override `pwd` unless we know that
the `builtin` command is available.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:14 -08:00
Johannes Schindelin
376cd722dd tests: use the correct path separator with BusyBox
BusyBox-w32 is a true Win32 application, i.e. it does not come with a
POSIX emulation layer.

That also means that it does *not* use the Unix convention of separating
the entries in the PATH variable using colons, but semicolons.

However, there are also BusyBox ports to Windows which use a POSIX
emulation layer such as Cygwin's or MSYS2's runtime, i.e. using colons
as PATH separators.

As a tell-tale, let's use the presence of semicolons in the PATH
variable: on Unix, it is highly unlikely that it contains semicolons,
and on Windows (without POSIX emulation), it is virtually guaranteed, as
everybody should have both $SYSTEMROOT and $SYSTEMROOT/system32 in their
PATH.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:14 -08:00
Bert Belder
f385152c68 Win32: symlink: add test for symlink attribute
To verify that the symlink is resolved correctly, we use the fact that
`git.exe` is a native Win32 program, and that `git.exe config -f <path>`
therefore uses the native symlink resolution.

Signed-off-by: Bert Belder <bertbelder@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
6884be78c6 mingw: Windows Docker volumes are *not* symbolic links
... even if they may look like them.

As looking up the target of the "symbolic link" (just to see whether it
starts with `/ContainerMappedDirectories/`) is pretty expensive, we
do it when we can be *really* sure that there is a possibility that this
might be the case.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: JiSeop Moon <zcube@zcube.kr>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
0f85860d90 mingw: special-case index entries for symlinks with buggy size
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>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
87fb8ed931 Unbreak interactive GPG prompt upon signing
With the recent update in efee955 (gpg-interface: check gpg signature
creation status, 2016-06-17), we ask GPG to send all status updates to
stderr, and then catch the stderr in an strbuf.

But GPG might fail, and send error messages to stderr. And we simply
do not show them to the user.

Even worse: this swallows any interactive prompt for a passphrase. And
detaches stderr from the tty so that the passphrase cannot be read.

So while the first problem could be fixed (by printing the captured
stderr upon error), the second problem cannot be easily fixed, and
presents a major regression.

So let's just revert commit efee9553a4.

This fixes https://github.com/git-for-windows/git/issues/871

Cc: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
4a3ad211e9 compat/fsmonitor/fsm-*-win32: support long paths
Update wchar_t buffers to use MAX_LONG_PATH instead of MAX_PATH in
the Win32 backend source files.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
5a9521c026 mingw: ensure that core.longPaths is handled *always*
A ton of Git commands simply do not read (or at least parse) the core.*
settings. This is not good, as Git for Windows relies on the
core.longPaths setting to be read quite early on.

So let's just make sure that all commands read the config and give
platform_core_config() a chance.

This patch teaches tons of Git commands to respect the config setting
`core.longPaths = true`, including `pack-refs`, thereby fixing
https://github.com/git-for-windows/git/issues/1218

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
ae0072ed85 tests: only override sort & find if there are usable ones in /usr/bin/
The idea is to allow running the test suite on MinGit with BusyBox
installed in /mingw64/bin/sh.exe. In that case, we will want to exclude
sort & find (and other Unix utilities) from being bundled.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Bert Belder
cf732ad2ba mingw: allow to specify the symlink type in .gitattributes
On Windows, symbolic links have a type: a "file symlink" must point at
a file, and a "directory symlink" must point at a directory. If the
type of symlink does not match its target, it doesn't work.

Git does not record the type of symlink in the index or in a tree. On
checkout it'll guess the type, which only works if the target exists
at the time the symlink is created. This may often not be the case,
for example when the link points at a directory inside a submodule.

By specifying `symlink=file` or `symlink=dir` the user can specify what
type of symlink Git should create, so Git doesn't have to rely on
unreliable heuristics.

Signed-off-by: Bert Belder <bertbelder@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
JiSeop Moon
a914067228 mingw: move the file_attr_to_st_mode() function definition
In preparation for making this function a bit more complicated (to allow
for special-casing the `ContainerMappedDirectories` in Windows
containers, which look like a symbolic link, but are not), let's move it
out of the header.

Signed-off-by: JiSeop Moon <zcube@zcube.kr>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
ca1233b0bb mingw: emulate stat() a little more faithfully
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()` for 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>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
628f2322ed mingw (git_terminal_prompt): do fall back to CONIN$/CONOUT$ method
To support Git Bash running in a MinTTY, we use a dirty trick to access
the MSYS2 pseudo terminal: we execute a Bash snippet that accesses
/dev/tty.

The idea was to fall back to writing to/reading from CONOUT$/CONIN$ if
that Bash call failed because Bash was not found.

However, we should fall back even in other error conditions, because we
have not successfully read the user input. Let's make it so.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
d89a17a1f3 Win32: fix 'lstat("dir/")' with long paths
Use a suffciently large buffer to strip the trailing slash.

Signed-off-by: Karsten Blees <blees@dcon.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
6b85691ca4 tests: move test PNGs into t/lib-diff/
We already have a directory where we store files intended for use by
multiple test scripts. The same directory is a better home for the
test-binary-*.png files than t/.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
9c0cdc3140 Introduce helper to create symlinks that knows about index_state
On Windows, symbolic links actually have a type depending on the target:
it can be a file or a directory.

In certain circumstances, this poses problems, e.g. when a symbolic link
is supposed to point into a submodule that is not checked out, so there
is no way for Git to auto-detect the type.

To help with that, we will add support over the course of the next
commits to specify that symlink type via the Git attributes. This
requires an index_state, though, something that Git for Windows'
`symlink()` replacement cannot know about because the function signature
is defined by the POSIX standard and not ours to change.

So let's introduce a helper function to create symbolic links that
*does* know about the index_state.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
JiSeop Moon
0ad5f54af1 mingw: when running in a Windows container, try to rename() harder
It is a known issue that a rename() can fail with an "Access denied"
error at times, when copying followed by deleting the original file
works. Let's just fall back to that behavior.

Signed-off-by: JiSeop Moon <zcube@zcube.kr>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
f3fc327f0f mingw: try to create symlinks without elevated permissions
With 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/

This patch is loosely based on the patch submitted by Samuel D. Leslie
as https://github.com/git-for-windows/git/pull/1184.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
7404cb8e91 compat/terminal.c: only use the Windows console if bash 'read -r' fails
Accessing the Windows console through the special CONIN$ / CONOUT$ devices
doesn't work properly for non-ASCII usernames an passwords.

It also doesn't work for terminal emulators that hide the native console
window (such as mintty), and 'TERM=xterm*' is not necessarily a reliable
indicator for such terminals.

The new shell_prompt() function, on the other hand, works fine for both
MSys1 and MSys2, in native console windows as well as mintty, and properly
supports Unicode. It just needs bash on the path (for 'read -s', which is
bash-specific).

On Windows, try to use the shell to read from the terminal. If that fails
with ENOENT (i.e. bash was not found), use CONIN/OUT as fallback.

Note: To test this, create a UTF-8 credential file with non-ASCII chars,
e.g. in git-bash: 'echo url=http://täst.com > cred.txt'. Then in git-cmd,
'git credential fill <cred.txt' works (shell version), while calling git
without the git-wrapper (i.e. 'mingw64\bin\git credential fill <cred.txt')
mangles non-ASCII chars in both console output and input.

Signed-off-by: Karsten Blees <blees@dcon.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
b9397bd8ab gitattributes: mark .png files as binary
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Bert Belder
c3c65f5995 Win32: symlink: move phantom symlink creation to a separate function
Signed-off-by: Bert Belder <bertbelder@gmail.com>
2022-01-24 11:15:13 -08:00
JiSeop Moon
443b1e4f49 mingw: introduce code to detect whether we're inside a Windows container
This will come in handy in the next commit.

Signed-off-by: JiSeop Moon <zcube@zcube.kr>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
042e7ff6cf Win32: symlink: add support for symlinks to directories
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 doesn't seem to care.
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.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
e512125c8a mingw: Support git_terminal_prompt with more terminals
The `git_terminal_prompt()` function expects the terminal window to be
attached to a Win32 Console. However, this is not the case with terminal
windows other than `cmd.exe`'s, e.g. with MSys2's own `mintty`.

Non-cmd terminals such as `mintty` still have to have a Win32 Console
to be proper console programs, but have to hide the Win32 Console to
be able to provide more flexibility (such as being resizeable not only
vertically but also horizontally). By writing to that Win32 Console,
`git_terminal_prompt()` manages only to send the prompt to nowhere and
to wait for input from a Console to which the user has no access.

This commit introduces a function specifically to support `mintty` -- or
other terminals that are compatible with MSys2's `/dev/tty` emulation. We
use the `TERM` environment variable as an indicator for that: if the value
starts with "xterm" (such as `mintty`'s "xterm_256color"), we prefer to
let `xterm_prompt()` handle the user interaction.

The most prominent user of `git_terminal_prompt()` is certainly
`git-remote-https.exe`. It is an interesting use case because both
`stdin` and `stdout` are redirected when Git calls said executable, yet
it still wants to access the terminal.

When running inside a `mintty`, the terminal is not accessible to the
`git-remote-https.exe` program, though, because it is a MinGW program
and the `mintty` terminal is not backed by a Win32 console.

To solve that problem, we simply call out to the shell -- which is an
*MSys2* program and can therefore access `/dev/tty`.

Helped-by: nalla <nalla@hamal.uberspace.de>
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
34b005f968 tests(mingw): if iconv is unavailable, use test-helper --iconv
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
244611982b Win32: implement basic symlink() functionality (file symlinks only)
Implement symlink() that always creates file symlinks. Fails with ENOSYS
if symlinks are disabled or unsupported.

Note: CreateSymbolicLinkW() was introduced with symlink support in Windows
Vista. For compatibility with Windows XP, we need to load it dynamically
and fail gracefully if it isnt's available.

Signed-off-by: Karsten Blees <blees@dcon.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
3edab306f9 test-tool: learn to act as a drop-in replacement for iconv
It is convenient to assume that everybody who wants to build & test Git
has access to a working `iconv` executable (after all, we already pretty
much require libiconv).

However, that limits esoteric test scenarios such as Git for Windows',
where an end user installation has to ship with `iconv` for the sole
purpose of being testable. That payload serves no other purpose.

So let's just have a test helper (to be able to test Git, the test
helpers have to be available, after all) to act as `iconv` replacement.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Bill Zissimopoulos
6487f16a42 mingw: lstat: compute correct size for symlinks
This commit fixes mingw_lstat by computing the proper size for symlinks
according to POSIX. 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".

Prior to this commit the mingw_lstat function returned a fixed size of
4096. This caused problems in git repositories that were 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 4096; at a later time git for Cygwin or git for WSL would find
that symlinks have changed size during `git status`. Vice versa doing
`git reset --hard` in git for Cygwin or git for WSL would update the
size of symlinks in the index with the correct value, only for git for
Windows to find incorrectly at a later time that the size had changed.

Signed-off-by: Bill Zissimopoulos <billziss@navimatics.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
ed15090f47 tests: replace mingw_test_cmp with a helper in C
This helper is slightly more performant than the script with MSYS2's
Bash. And a lot more readable.

To accommodate t1050, which wants to compare files weighing in with 3MB
(falling outside of t1050's malloc limit of 1.5MB), we simply lift the
allocation limit by setting the environment variable GIT_ALLOC_LIMIT to
zero when calling the helper.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
43f0262b80 Win32: implement readlink()
Implement readlink() by reading NTFS reparse points. Works for symlinks
and directory junctions. If symlinks are disabled, fail with ENOSYS.

Signed-off-by: Karsten Blees <blees@dcon.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
28689ef32b test-lib: avoid unnecessary Perl invocation
It is a bit strange, and even undesirable, to require Perl just to run
the test suite even when NO_PERL was set.

This patch does not fix this problem by any stretch of imagination.
However, it fixes *the* Perl invocation that *every single* test script
has to run.

While at it, it makes the source code also more grep'able, as the code
that unsets some, but not all, GIT_* environment variables just became a
*lot* more explicit. And all that while still reducing the total number
of lines.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
71042ba0ab Win32: mingw_chdir: change to symlink-resolved directory
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 <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
51b1cec839 mingw: when path_lookup() failed, try BusyBox
BusyBox comes with a ton of applets ("applet" being the identical
concept to Git's "builtins"). And similar to Git's builtins, the applets
can be called via `busybox <command>`, or the BusyBox executable can be
copied/hard-linked to the command name.

The similarities do not end here. Just as with Git's builtins, it is
problematic that BusyBox' hard-linked applets cannot easily be put into
a .zip file: .zip archives have no concept of hard-links and therefore
would store identical copies (and also extract identical copies,
"inflating" the archive unnecessarily).

To counteract that issue, MinGit already ships without hard-linked
copies of the builtins, and the plan is to do the same with BusyBox'
applets: simply ship busybox.exe as single executable, without
hard-linked applets.

To accommodate that, Git is being taught by this commit a very special
trick, exploiting the fact that it is possible to call an executable
with a command-line whose argv[0] is different from the executable's
name: when `sh` is to be spawned, and no `sh` is found in the PATH, but
busybox.exe is, use that executable (with unchanged argv).

Likewise, if any executable to be spawned is not on the PATH, but
busybox.exe is found, parse the output of `busybox.exe --help` to find
out what applets are included, and if the command matches an included
applet name, use busybox.exe to execute it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
15657f8824 Win32: mingw_rename: support renaming symlinks
MSVCRT's _wrename() cannot rename symlinks over existing files: it returns
success without doing anything. Newer MSVCR*.dll versions probably do not
have this problem: according to CRT sources, they just call MoveFileEx()
with the MOVEFILE_COPY_ALLOWED flag.

Get rid of _wrename() and call MoveFileEx() with proper error handling.

Signed-off-by: Karsten Blees <blees@dcon.de>
2022-01-24 11:15:13 -08:00
Johannes Schindelin
4ef9f4b4a4 mingw: explicitly specify with which cmd to prefix the cmdline
The main idea of this patch is that even if we have to look up the
absolute path of the script, if only the basename was specified as
argv[0], then we should use that basename on the command line, too, not
the absolute path.

This patch will also help with the upcoming patch where we automatically
substitute "sh ..." by "busybox sh ..." if "sh" is not in the PATH but
"busybox" is: we will do that by substituting the actual executable, but
still keep prepending "sh" to the command line.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
75fc0369b2 Win32: mingw_unlink: support symlinks to directories
_wunlink() / DeleteFileW() refuses to delete symlinks to directories. If
_wunlink() fails with ERROR_ACCESS_DENIED, try _wrmdir() as well.

Signed-off-by: Karsten Blees <blees@dcon.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
1b446b80d0 Win32: add symlink-specific error codes
Signed-off-by: Karsten Blees <blees@dcon.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
5e4104f30e Win32: change default of 'core.symlinks' to false
Symlinks on Windows don't work the same way as on Unix systems. E.g. there
are different types of symlinks for directories and files, creating
symlinks requires administrative privileges etc.

By default, disable symlink support on Windows. I.e. users explicitly have
to enable it with 'git config [--system|--global] core.symlinks true'.

The test suite ignores system / global config files. Allow testing *with*
symlink support by checking if native symlinks are enabled in MSys2 (via
'MSYS=winsymlinks:nativestrict').

Reminder: This would need to be changed if / when we find a way to run the
test suite in a non-MSys-based shell (e.g. dash).

Signed-off-by: Karsten Blees <blees@dcon.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
4c02239d59 Win32: factor out retry logic
The retry pattern is duplicated in three places. It also seems to be too
hard to use: 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.

mingw_unlink: include _wchmod in the retry loop (which may fail if the
file is locked exclusively).

mingw_rmdir: include special error handling in the retry loop.

Signed-off-by: Karsten Blees <blees@dcon.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
630009e3df Win32: lstat(): return adequate stat.st_size for symlinks
Git typically doesn't trust the stat.st_size member of symlinks (e.g. see
strbuf_readlink()). However, some functions take shortcuts if st_size is 0
(e.g. diff_populate_filespec()).

In mingw_lstat() and fscache_lstat(), make sure to return an adequate size.

The extra overhead of opening and reading the reparse point to calculate
the exact size is not necessary, as git doesn't rely on the value anyway.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00
Karsten Blees
0c45a293ce mingw: teach fscache and dirent about symlinks
Move S_IFLNK detection to file_attr_to_st_mode() and reuse it in fscache.

Implement DT_LNK detection in dirent.c and the fscache readdir version.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-24 11:15:13 -08:00