Commit Graph

826 Commits

Author SHA1 Message Date
Johannes Schindelin 4840a56325
Cygwin: Adjust CWD magic to accommodate for the latest Windows previews
Reportedly Windows 11 build 25*** from Insider changed the current
working directory logic a bit, and Cygwin's "magic" (or:
"technologically sufficiently advanced") code needs to be adjusted
accordingly.

This fixes https://github.com/git-for-windows/git/issues/4429

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2023-05-24 20:44:52 +01:00
Corinna Vinschen 2898a359b8 Cygwin: dirname: fix handling of leading slashes
Per https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/xbd_chap04.html:

  "A pathname that begins with two successive slashes may be interpreted
   in an implementation-defined manner, although more than two leading
   slashes shall be treated as a single slash."

So more than 2 leading slashes are supposed to be folded into one,
which our dirname neglected.  Fix that.

Fixes: 24e8fc6872 ("* cygwin.din (basename): Export.")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2023-03-29 10:23:05 +02:00
Corinna Vinschen 09cb4cd294 Cygwin: path_conv: make sure sym.path_flags is always initialized
Commit c1023ee353 introduced a split between mount flags and
path flags.  It didn't initialize symlink_info::path_flags in
path_conv::check, because that's done in symlink_info::check.

However, there are two code paths expecting symlink_info::path_flags
being already initialized and both skip symlink_info::check.

Make sure symlink_info::path_flags is initalized to 0 early in
path_conv::check.

Fixes: c1023ee353 ("Cygwin: path_conv: decouple path_types from mount types")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2022-12-21 13:13:24 +01:00
Corinna Vinschen fd3ce87f73 Cygwin: check_reparse_point_target: fix comment format
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2022-12-20 10:13:59 +01:00
Corinna Vinschen 5ba5e09b9d Cygwin: path handling: never substitute virtual drive with target path
Move the drive substitution code after the call to
GetFinalPathNameByHandleW into a local function revert_virtual_drive
and add code to handle non-remote virtual drives, i. e., those
created with the subst command.  (Try to) make sure that virtual
drives are never treated like symlinks.

Fixes: 19d59ce75d ("Cygwin: path_conv: Rework handling native symlinks as inner path components")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2022-12-12 21:56:14 +01:00
Corinna Vinschen 6951d258eb Cygwin: simplify FAST_CWD access
Dropping Windows 7 and 8 also drops the need to handle three
different FAST_CWD structures.  Simplify code accordingly.

While at it, use dynamic allocation of the FAST_CWD structure
based on the length of the CWD path.  This may help in future
to enable working with systems and native apps with long paths
enabled (Win 10 1607 and later), see
https://learn.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation?tabs=registry#enable-long-paths-in-windows-10-version-1607-and-later

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2022-12-04 14:01:41 +01:00
Corinna Vinschen 0819679a7a Cygwin: cwd: use SRWLOCK instead of muto
To reduce thread contention, use reader/writer locks as required.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2022-08-23 12:09:44 +02:00
Ken Brown 5cdf8ade28 Cygwin: fix return value of symlink_info::check
Currently it is possible for symlink_info::check to return -1 in case
we're searching for foo and find foo.lnk that is not a Cygwin symlink.
This contradicts the new meaning attached to a negative return value
in commit 19d59ce75d.  Fix this by setting "res" to 0 at the beginning
of the main loop and not seting it to -1 later.

Also fix the commentary preceding the function definition to reflect
the current behavior.

Addresses: https://cygwin.com/pipermail/cygwin/2022-August/252030.html
2022-08-09 16:58:08 -04:00
Corinna Vinschen d097a96e6e Cygwin: drop last usage of RtlCreateUnicodeStringFromAsciiz
This function is just bad.  It really only works for ASCII
chars, everything else is broken after the conversion.

Introduce new helper function sys_mbstouni to replace
RtlCreateUnicodeStringFromAsciiz in hash_path_name.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2022-08-05 11:45:49 +02:00
Takashi Yano 8b502d8635 Cygwin: path: Make some symlinks to /cygdrive/* work.
- Previously, some symbolic links to /cygdrive/* (e.g. /cygdrive/C,
  /cygdrive/./c, /cygdrive//c, etc.) did not work. This patch fixes
  the issue.
  Addresses: https://cygwin.com/pipermail/cygwin/2022-July/251994.html
2022-08-03 13:36:09 +09:00
Ken Brown e1ce752a1d Cygwin: remove miscellaneous 32-bit code 2022-05-29 17:54:32 -04:00
Ken Brown 3e917daec1 Cygwin: remove some 32-bit only path conversion functions 2022-05-29 17:45:52 -04:00
Ken Brown 2126f966ae Cygwin: remove regparm.h
This file defines the macros __reg1, __reg2, and __reg3, which are
defined to be empty on 64-bit Cygwin.  Remove all occurrences of these
macros.
2022-05-29 17:45:52 -04:00
Ken Brown 2d9b48760c Cygwin: simplify some function names
Remove "32" or "64" from each of the following names: acl32,
aclcheck32, aclfrommode32, aclfrompbits32, aclfromtext32, aclsort32,
acltomode32, acltopbits32, acltotext32, facl32, fchown32, fcntl64,
fstat64, _fstat64, _fstat64_r, ftruncate64, getgid32, getgrent32,
getgrgid32, getgrnam32, getgroups32, getpwuid32, getpwuid_r32,
getuid32, getuid32, initgroups32, lseek64, lstat64, mknod32, mmap64,
setegid32, seteuid32, setgid32, setgroups32, setregid32, setreuid32,
setuid32, stat64, _stat64_r, truncate64.

Remove prototypes and macro definitions of these names.

Remove "#ifndef __INSIDE_CYGWIN__" from some headers so that the new
names will be available when compiling Cygwin.

Remove aliases that are no longer needed.

Include <unistd.h> in fhandler_clipboard.cc for the declarations of
geteuid and getegid.
2022-05-29 17:45:52 -04:00
Corinna Vinschen d4df9c6de1 Cygwin: drop a few minor references to WOW64
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2022-05-13 14:32:21 +02:00
Corinna Vinschen 2610b681a4 Cygwin: wincap: drop wow64 flag and all conditions depending on it
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2022-05-13 14:15:47 +02:00
Takashi Yano 0dad577b4b Cygwin: path: Convert type of variable 'remlen' to DWORD.
- Variable remlen stores the return value of QueryDosDeviceW(), so
  it is better to be DWORD.
2022-03-14 21:56:03 +09:00
Takashi Yano 7df94e3b4f Cygwin: path: Add fallback for DFS mounted drive.
- If UNC path for DFS is mounted to a drive with drive letter, the
  error "Too many levels of symbolic links" occurs when accessing
  to that drive. This is because GetDosDeviceW() returns unexpected
  string such as "\Device\Mup\DfsClient\;Z:000000000003fb89\dfsserver
  \dfs\linkname" for the mounted UNC path "\??\UNC\fileserver\share".
  This patch adds a workaround for this issue.

  Addresses: https://cygwin.com/pipermail/cygwin/2022-March/250979.html
2022-03-14 20:29:23 +09:00
Takashi Yano e5aca9ced9 Cygwin: path: Fix UNC path handling for SMB3 mounted to a drive.
- If an UNC path is mounted to a drive using SMB3.11, accessing to
  the drive fails with error "Too many levels of symbolic links."
  This patch fixes the issue.
2022-02-03 12:21:21 +09:00
Johannes Schindelin bd4fdcc059 Cygwin: path_conv: do not get confused by a directory with `.lnk` suffix
When trying to create a directory called `xyz` in the presence of a
directory `xyz.lnk`, the Cygwin runtime errors out with an `ENOENT`.

The root cause is actually a bit deeper: the `symlink_info::check()`
method tries to figure out whether the given path refers to a symbolic
link as emulated via `.lnk` files, but since it is a directory, that is
not the case, and that hypothesis is rejected.

However, the `fileattr` field is not cleared, so that a later
`.exists()` call on the instance mistakenly thinks that the symlink
actually exists. Let's clear that field.

This fixes https://github.com/msys2/msys2-runtime/issues/81

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-01-18 11:55:44 +01:00
Takashi Yano 5aa2be8ac2 Cygwin: path: Fix path conversion of virtual drive.
- The last change in path.cc introduced a bug that causes an error
  when accessing a virtual drive which mounts UNC path such as
  "\\server\share\dir" rather than "\\server\share". This patch
  fixes the issue.
2021-12-11 22:49:52 +09:00
Takashi Yano 30089b3fbd Cygwin: path: Convert UNC path prefix back to drive letter.
- When symlink_info::check() is called with the path having drive
  letter and UNC path is mounted to the drive, the path is replaced
  with UNC path. With this patch, UNC path prefix is converted back
  to drive letter.  This fixes the issue:
  https://cygwin.com/pipermail/cygwin/2021-November/250087.html
  https://cygwin.com/pipermail/cygwin/2021-December/250103.html
2021-12-08 20:20:30 +09:00
Corinna Vinschen 9980177def Revert "Cygwin: set the FILE_ATTRIBUTE_ARCHIVE DOS attribute on file creation"
This reverts commit 2b28977149.

This patch fixes the symptoms, but not the actual problem.  Revert
and try again.
2021-11-16 19:58:56 +01:00
Corinna Vinschen 2b28977149 Cygwin: set the FILE_ATTRIBUTE_ARCHIVE DOS attribute on file creation
Do this for normal files and symlinks, not for temporary files,
device files or unix sockets.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-11-15 20:59:41 +01:00
Jon Turney 38965159df
Cygwin: Add winsymlinks:sys
Add winsymlinks:sys, to explicitly select always using plain files with
the system attribute containing a magic cookie to represent a symlink.
2021-07-30 15:48:26 +01:00
Jon Turney 66eefa25f2
Cygwin: Rename WSYM_sysfile to WSYM_default
Rename WSYM_sysfile to WSYM_default, since it selects more than just
sysfile with magic cookie now.
2021-07-30 15:48:21 +01:00
Jeremy Drake 4fca7b0da6 Cygwin: respect PC_SYM_FOLLOW and PC_SYM_NOFOLLOW_REP with inner links.
The new GetFinalPathNameW handling for native symlinks in inner path
components is disabled if caller doesn't want to follow symlinks, or
doesn't want to follow reparse points.
2021-07-07 10:46:06 +02:00
Jeremy Drake d0e42141b8 Revert "Cygwin: Handle virtual drives as non-symlinks"
This reverts commit c8949d0400.
2021-07-06 16:57:02 +02:00
Corinna Vinschen 782b338530 Cygwin: path_conv: fix mqueue path check
The check for a file or dir within /dev/mqueue is accidentally using
the incoming path, which could be a relative path.  Make sure to
restore the absolute POSIX path in path_copy and only then test the
path.

Also, move the actual check for a valid path below /dev/mqueue into
the fhandler_mqueue class.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-05-25 22:03:36 +02:00
Corinna Vinschen 4c09dc4f9c Cygwin: cwdstuff: check if /dev exists
/dev has been handled as virtual dir in cwdstuff, thus not allowing
to start native apps from /dev as CWD, even if /dev actually exists
on disk.  Unfortunately this also affects Cygwin executables started
from a debugger.

When chdir'ing to /dev, check if /dev exists on disk.  If so, treat
it as any other existing path.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-05-25 21:46:13 +02:00
Corinna Vinschen b62450cf17 Cygwin: POSIX msg queues: implement open/mq_open entirely in fhandler
The mq_open call is just a framework now.  This patch moves the
entire functionality into fhandler_mqueue.  To support standard
OS calls (as on Linux), make fhandler_mqueue a derived class from
fhandler_disk_file and keep the base handle the handle to the
default stream, to allow implementing O_PATH functionlaity as well
as reading from the file and NOT reading binary message queue data.

Implement a standard fhandler_mqueue::open method, allowing, for
instance, to touch a file under /dev/mqueue and if it doesn't exist,
to create a message queue file.

FIXME: This introduces a BAD HACK into path_conv::check, which needs
reviewing.

Keep the posix path intact in the fhandler, and change get_proc_fd_name
accordingly to return only the basename plus leading slash for
/proc/<PID>/fd.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-05-25 16:49:04 +02:00
Corinna Vinschen 15c96f2b26 Cygwin: get_nt_native_path: allow to append suffix
POSIX message queues will be moved into NTFS streams.
Extend get_nt_native_path to provide a filename suffix which is not
subject to special character transposition, to allow specifying
a colon.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-05-25 16:31:26 +02:00
Jeremy Drake 338548f82f Cygwin: suppress FAST_CWD warnings on ARM64
The old check was insufficient: new insider preview builds of Windows
allow running x86_64 process on ARM64.  The IsWow64Process2 function
seems to be the intended way to figure this situation out.
2021-05-19 14:40:51 +02:00
Jeremy Drake c8949d0400 Cygwin: Handle virtual drives as non-symlinks
This avoids MAX_PATH-related problems in native tools in case the
virtual drive points to a deep directory

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-05-19 14:40:51 +02:00
Corinna Vinschen 44eb416323 Cygwin: fetch Windows directory on all platforms and use throughout
Rather than fetching the system Windows directory at dll init time
only on 32 bit, fetch it on all platforms.  Store as WCHAR and
UNICODE_STRING.  Use where appropriate to simplify code.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-05-07 23:05:24 +02:00
Corinna Vinschen 19d59ce75d Cygwin: path_conv: Rework handling native symlinks as inner path components
commit 456c3a4638 was only going half-way.  It handled symlinks and
junction points as inner path components and made realpath return the
correct path, but it ignored drive letter substitution, i. e., virtual
drives created with, e. g.

  subst X: C:\foo\bar

It was also too simple.  Just returning an error code from
symlink_info::check puts an unnecessary onus on the symlink evaluation
loop in path_conv::check.

Rework the code to use GetFinalPathNameByHandle, and only do this after
checking the current file for being a symlink failed.

If the final path returned by GetFinalPathNameByHandle is not the same
as the incoming path, replace the incoming path with the POSIXified
final path.  This also short-circuits path evaluation, because
path_conv::check doesn't have to recurse over the inner path components
multiple times if all symlinks are of a native type, while still getting
the final path as end result.

Virtual drives are now handled like symlinks.  This is a necessary change
from before to make sure virtual drives are handled identically across
different access methods.  An example is realpath(1) from coreutils.  It
doesn't call readlink(2), but iterates over all path components using
lstat/readlink calls.  Both methods should result in the same real path.

Fixes: 456c3a4638 ("path_conv: Try to handle native symlinks more sanely")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-05-07 22:52:16 +02:00
Corinna Vinschen 13fd26ecf5 Cygwin: skip native symlink check in Windows dir under WOW64
Commit 456c3a4638 added a workaround when handling paths with native
symlinks as inner path components.  This patch introduced a problem for
paths handled by the WOW64 File System Redirector (FSR).

Fix this problem by not performing the new code from commit 456c3a4638
for paths under the Windows directory.  Only do this in WOW64.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-04-21 17:41:08 +02:00
Corinna Vinschen 456c3a4638 Cygwin: path_conv: Try to handle native symlinks more sanely
For local paths, add a check if the inner path components contain native
symlinks or junctions.  Compare the incoming path with the path returned
by NtQueryInformationFile(FileNameInformation).  If they differ, there
must be at least one native symlink or junction in the path.  If so,
treat the currently evaluated file as non-existant.  This forces
path_conv::check to backtrack inner path components until we eliminated
all native symlinks or junctions and have a normalized path.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2021-04-19 14:49:14 +02:00
Johannes Schindelin 0631c6644e Cygwin: Treat Windows Store's "app execution aliases" as symbolic links
When the Windows Store version of Python is installed, so-called "app
execution aliases" are put into the `PATH`. These are reparse points
under the hood, with an undocumented format.

We do know a bit about this format, though, as per the excellent analysis:
https://www.tiraniddo.dev/2019/09/overview-of-windows-execution-aliases.html

	The first 4 bytes is the reparse tag, in this case it's
	0x8000001B which is documented in the Windows SDK as
	IO_REPARSE_TAG_APPEXECLINK. Unfortunately there doesn't seem to
	be a corresponding structure, but with a bit of reverse
	engineering we can work out the format is as follows:

	Version: <4 byte integer>
	Package ID: <NUL Terminated Unicode String>
	Entry Point: <NUL Terminated Unicode String>
	Executable: <NUL Terminated Unicode String>
	Application Type: <NUL Terminated Unicode String>

Let's treat them as symbolic links. For example, in this developer's
setup, this will result in the following nice output:

	$ cd $LOCALAPPDATA/Microsoft/WindowsApps/

	$ ls -l python3.exe
	lrwxrwxrwx 1 me 4096 105 Aug 23  2020 python3.exe -> '/c/Program Files/WindowsApps/PythonSoftwareFoundation.Python.3.7_3.7.2544.0_x64__qbz5n2kfra8p0/python.exe'

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-03-23 16:54:37 +01:00
Ken Brown 05e2751665 Cygwin: recognize native Windows AF_UNIX sockets as reparse points
Allow check_reparse_point_target to recognize reparse points with
reparse tag IO_REPARSE_TAG_AF_UNIX.  These are used in recent versions
of Windows 10 to represent AF_UNIX sockets.

check_reparse_point_target now returns PATH_REP on files of this type,
so that they are treated as known reparse points (but not as sockets).
This allows tools like 'rm', 'ls', etc. to operate on these files.

Addresses: https://cygwin.com/pipermail/cygwin/2020-September/246362.html
	   https://cygwin.com/pipermail/cygwin/2021-January/247666.html
2021-02-01 09:55:40 -05:00
Ken Brown 4aefad2bb8 Cygwin: normalize_posix_path: fix error handling when .. is encountered
When .. is in the source path and the path prefix exists but is not a
directory, return ENOTDIR instead of ENOENT.  This fixes a POSIX
compliance issue for realpath(3):

  https://pubs.opengroup.org/onlinepubs/9699919799/functions/realpath.html

Addresses: https://lists.gnu.org/archive/html/bug-gnulib/2021-01/msg00214.html
2021-01-22 10:31:09 -05:00
Corinna Vinschen aec6479820 Cygwin: add flag to indicate reparse points unknown to WinAPI
https://cygwin.com/pipermail/cygwin/2020-December/246938.html
reports a problem where, when adding a Cygwin default symlink
to $PATH since Cygwin 3.1.5, $PATH handling appears to be broken.

3.1.5 switched to WSL symlinks as Cygwin default symlinks.

A piece of code in path handling skips resolving reparse points
if they are the last component in the path.  Thus a reparse point
in $PATH is not resolved but converted to Windows path syntax
verbatim.

If you do this with a WSL symlink, certain WinAPI functions fail.
The underlying $PATH handling fails to recognize the reparse
point in $PATH and returns with STATUS_IO_REPARSE_TAG_NOT_HANDLED.
As a result, the calling WinAPI function fails, most prominently
so CreateProcess.

Fix this problem by adding a PATH_REP_NOAPI bit to path_types
and a matching method path_conv::is_winapi_reparse_point().

Right now this flag is set for WSL symlinks and Cygwin AF_UNIX
sockets (new type implemented as reparse points).

The aforementioned code skipping repare point path resolution calls
is_winapi_reparse_point() rather than is_known_reparse_point(),
so now path resolution is only skipped for reparse points known
to WinAPI.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2020-12-02 16:14:41 +01:00
Christian Franke 3434d35a64 Cygwin: Fix access to block devices below /proc/sys.
Use fhandler_dev_floppy instead of fhandler_procsys for such devices.
The read()/write() functions from fhandler_procsys do not ensure
sector aligned transfers and lseek() fails always.

Signed-off-by: Christian Franke <franke@computer.org>
2020-11-30 11:53:00 +01:00
Ken Brown 0e29048956 Cygwin: always recognize AF_UNIX sockets as reparse points
If __WITH_AF_UNIX is defined when Cygwin is built, then a named
AF_UNIX socket is represented by a reparse point with a
Cygwin-specific tag and GUID.  Make such files recognizable as reparse
points (but not as sockets) even if __WITH_AF_UNIX is not defined.
That way utilities such as 'ls' and 'rm' still behave reasonably.

This requires two changes:

- Define the GUID __cygwin_socket_guid unconditionally.

- Make check_reparse_point_target return PATH_REP on a reparse point
  of this type if __WITH_AF_UNIX is not defined.
2020-10-04 12:53:05 -04:00
Ken Brown 0b4beaf46f Cygwin: fix handling of known reparse points that are not symlinks
Commit aa467e6e, "Cygwin: add AF_UNIX reparse points to path
handling", changed check_reparse_point_target so that it could return
a positive value on a known reparse point that is not a symlink.  But
some of the code in check_reparse_point that handles this positive
return value was executed unconditionally, when it should have been
executed only for symlinks.

As a result, posixify could be called on a buffer containing garbage,
and check_reparse_point could erroneously return a positive value on a
non-symlink.  This is now fixed so that posixify is only called if the
reparse point is a symlink, and check_reparse_point returns 0 if the
reparse point is not a symlink.

Also fix symlink_info::check to handle this last case, in which
check_reparse_point returns 0 on a known reparse point.
2020-10-04 12:53:05 -04:00
Ken Brown 6b6dd5fede Cygwin: check_reparse_point_target: update comment
Commit aa467e6e, "Cygwin: add AF_UNIX reparse points to path
handling", changed the return values of check_reparse_point_target.
Update the comment accordingly.
2020-09-26 16:44:44 -04:00
Ken Brown 6775ac8cb5 Cygwin: path_conv::check: handle error from fhandler_process::exists
fhandler_process::exists is called when we are checking a path
starting with "/proc/<pid>/fd".  If it returns virt_none and sets an
errno, there is no need for further checking.  Just set 'error' and
return.
2020-09-08 15:00:55 -04:00
Ken Brown c1f177d6a9 Cygwin: cwdstuff::get: clean up debug_printf output
Set errno = 0 at the beginning so that the debug_printf call at the
end doesn't report a nonzero errno left over from some other function
call.
2020-08-23 18:50:00 -04:00
Corinna Vinschen 50ad198085 Cygwin: Add 'fallthrough' pseudo keyword for switch/case use
This patch has been inspired by the Linux kernel patch

  294f69e662d1 compiler_attributes.h: Add 'fallthrough' pseudo keyword for switch/case use

written by Joe Perches <joe AT perches DOT com> based on an idea from
Dan Carpenter <dan DOT carpenter AT oracle DOT com>.  The following text
is from the original log message:

Reserve the pseudo keyword 'fallthrough' for the ability to convert the
various case block /* fallthrough */ style comments to appear to be an
actual reserved word with the same gcc case block missing fallthrough
warning capability.

All switch/case blocks now should end in one of:

	break;
	fallthrough;
	goto <label>;
	return [expression];
	continue;

In C mode, GCC supports the __fallthrough__ attribute since 7.1,
the same time the warning and the comment parsing were introduced.

Cygwin-only: add an explicit -Wimplicit-fallthrough=5 to the build
flags.
2020-08-05 21:58:22 +02:00
Corinna Vinschen 6b97962073 Cygwin: symlinks: fix WSL symlink creation if cygdrive prefix is /
If the cygdrive prefix is /, then the following happens right now:

  $ ln -s /tmp/foo .
  $ ls -l foo
  lrwxrwxrwx 1 user group 12 Apr 15 23:44 foo -> /mnt/tmp/foo

Fix this by skipping cygdrive prefix conversion to WSL drive
prefix "/mnt", if the cygdrive prefix is just "/".  There's no
satisfying way to do the right thing all the time in this case
anyway.  For a description and the alternatives, see
https://cygwin.com/pipermail/cygwin-developers/2020-April/011859.html

Also, fix a typo in a comment.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2020-04-21 10:39:36 +02:00