/*
 * tclWinFile.c --
 *
 *	This file contains temporary wrappers around UNIX file handling
 *	functions. These wrappers map the UNIX functions to Win32 HANDLE-style
 *	files, which can be manipulated through the Win32 console redirection
 *	interfaces.
 *
 * Copyright (c) 1995-1998 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tclWinInt.h"
#include "tclFileSystem.h"
#include <winioctl.h>
#include <shlobj.h>
#include <lm.h>		        /* For TclpGetUserHome(). */
#include <userenv.h>		/* For TclpGetUserHome(). */
#include <aclapi.h>             /* For GetNamedSecurityInfo */

#ifdef _MSC_VER
#   pragma comment(lib, "userenv.lib")
#endif
/*
 * The number of 100-ns intervals between the Windows system epoch (1601-01-01
 * on the proleptic Gregorian calendar) and the Posix epoch (1970-01-01).
 */

#define POSIX_EPOCH_AS_FILETIME	\
	((Tcl_WideInt)116444736 * (Tcl_WideInt)1000000000)

/*
 * Declarations for 'link' related information. This information should come
 * with VC++ 6.0, but is not in some older SDKs. In any case it is not well
 * documented.
 */

#ifndef IO_REPARSE_TAG_RESERVED_ONE
#  define IO_REPARSE_TAG_RESERVED_ONE	0x000000001
#endif
#ifndef IO_REPARSE_TAG_RESERVED_RANGE
#  define IO_REPARSE_TAG_RESERVED_RANGE	0x000000001
#endif
#ifndef IO_REPARSE_TAG_VALID_VALUES
#  define IO_REPARSE_TAG_VALID_VALUES	0x0E000FFFF
#endif
#ifndef IO_REPARSE_TAG_HSM
#  define IO_REPARSE_TAG_HSM		0x0C0000004
#endif
#ifndef IO_REPARSE_TAG_NSS
#  define IO_REPARSE_TAG_NSS		0x080000005
#endif
#ifndef IO_REPARSE_TAG_NSSRECOVER
#  define IO_REPARSE_TAG_NSSRECOVER	0x080000006
#endif
#ifndef IO_REPARSE_TAG_SIS
#  define IO_REPARSE_TAG_SIS		0x080000007
#endif
#ifndef IO_REPARSE_TAG_DFS
#  define IO_REPARSE_TAG_DFS		0x080000008
#endif

#ifndef IO_REPARSE_TAG_RESERVED_ZERO
#  define IO_REPARSE_TAG_RESERVED_ZERO	0x00000000
#endif
#ifndef FILE_FLAG_OPEN_REPARSE_POINT
#  define FILE_FLAG_OPEN_REPARSE_POINT	0x00200000
#endif
#ifndef IO_REPARSE_TAG_MOUNT_POINT
#  define IO_REPARSE_TAG_MOUNT_POINT	0xA0000003
#endif
#ifndef IsReparseTagValid
#  define IsReparseTagValid(x) \
    (!((x)&~IO_REPARSE_TAG_VALID_VALUES)&&((x)>IO_REPARSE_TAG_RESERVED_RANGE))
#endif
#ifndef IO_REPARSE_TAG_SYMBOLIC_LINK
#  define IO_REPARSE_TAG_SYMBOLIC_LINK	IO_REPARSE_TAG_RESERVED_ZERO
#endif
#ifndef FILE_SPECIAL_ACCESS
#  define FILE_SPECIAL_ACCESS		(FILE_ANY_ACCESS)
#endif
#ifndef FSCTL_SET_REPARSE_POINT
#  define FSCTL_SET_REPARSE_POINT \
    CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 41, METHOD_BUFFERED, FILE_SPECIAL_ACCESS)
#  define FSCTL_GET_REPARSE_POINT \
    CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 42, METHOD_BUFFERED, FILE_ANY_ACCESS)
#  define FSCTL_DELETE_REPARSE_POINT \
    CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 43, METHOD_BUFFERED, FILE_SPECIAL_ACCESS)
#endif
#ifndef INVALID_FILE_ATTRIBUTES
#define INVALID_FILE_ATTRIBUTES		((DWORD)-1)
#endif

/*
 * Maximum reparse buffer info size. The max user defined reparse data is
 * 16KB, plus there's a header.
 */

#define MAX_REPARSE_SIZE		17000

/*
 * Undocumented REPARSE_MOUNTPOINT_HEADER_SIZE structure definition. This is
 * found in winnt.h.
 *
 * IMPORTANT: caution when using this structure, since the actual structures
 * used will want to store a full path in the 'PathBuffer' field, but there
 * isn't room (there's only a single WCHAR!). Therefore one must artificially
 * create a larger space of memory and then cast it to this type. We use the
 * 'DUMMY_REPARSE_BUFFER' struct just below to deal with this problem.
 */

#define REPARSE_MOUNTPOINT_HEADER_SIZE	 8
#ifndef REPARSE_DATA_BUFFER_HEADER_SIZE
typedef struct _REPARSE_DATA_BUFFER {
    DWORD ReparseTag;
    WORD ReparseDataLength;
    WORD Reserved;
    union {
	struct {
	    WORD SubstituteNameOffset;
	    WORD SubstituteNameLength;
	    WORD PrintNameOffset;
	    WORD PrintNameLength;
	    ULONG Flags;
	    WCHAR PathBuffer[1];
	} SymbolicLinkReparseBuffer;
	struct {
	    WORD SubstituteNameOffset;
	    WORD SubstituteNameLength;
	    WORD PrintNameOffset;
	    WORD PrintNameLength;
	    WCHAR PathBuffer[1];
	} MountPointReparseBuffer;
	struct {
	    BYTE DataBuffer[1];
	} GenericReparseBuffer;
    };
} REPARSE_DATA_BUFFER;
#endif

typedef struct {
    REPARSE_DATA_BUFFER dummy;
    WCHAR dummyBuf[MAX_PATH * 3];
} DUMMY_REPARSE_BUFFER;

/*
 * Other typedefs required by this code.
 */

static time_t		ToCTime(FILETIME fileTime);
static void		FromCTime(time_t posixTime, FILETIME *fileTime);

/*
 * Declarations for local functions defined in this file:
 */

static int		NativeAccess(const WCHAR *path, int mode);
static int		NativeDev(const WCHAR *path);
static int		NativeStat(const WCHAR *path, Tcl_StatBuf *statPtr,
			    int checkLinks);
static unsigned short	NativeStatMode(DWORD attr, int checkLinks,
			    int isExec);
static int		NativeIsExec(const WCHAR *path);
static int		NativeReadReparse(const WCHAR *LinkDirectory,
			    REPARSE_DATA_BUFFER *buffer, DWORD desiredAccess);
static int		NativeWriteReparse(const WCHAR *LinkDirectory,
			    REPARSE_DATA_BUFFER *buffer);
static int		NativeMatchType(int isDrive, DWORD attr,
			    const WCHAR *nativeName, Tcl_GlobTypeData *types);
static int		WinIsDrive(const char *name, size_t nameLen);
static int		WinIsReserved(const char *path);
static Tcl_Obj *	WinReadLink(const WCHAR *LinkSource);
static Tcl_Obj *	WinReadLinkDirectory(const WCHAR *LinkDirectory);
static int		WinLink(const WCHAR *LinkSource,
			    const WCHAR *LinkTarget, int linkAction);
static int		WinSymLinkDirectory(const WCHAR *LinkDirectory,
			    const WCHAR *LinkTarget);

/*
 *--------------------------------------------------------------------
 *
 * WinLink --
 *
 *	Make a link from source to target.
 *
 *--------------------------------------------------------------------
 */

static int
WinLink(
    const WCHAR *linkSourcePath,
    const WCHAR *linkTargetPath,
    int linkAction)
{
    WCHAR tempFileName[MAX_PATH];
    WCHAR *tempFilePart;
    DWORD attr;

    /*
     * Get the full path referenced by the target.
     */

    if (!GetFullPathNameW(linkTargetPath, MAX_PATH, tempFileName,
	    &tempFilePart)) {
	/*
	 * Invalid file.
	 */

	TclWinConvertError(GetLastError());
	return -1;
    }

    /*
     * Make sure source file doesn't exist.
     */

    attr = GetFileAttributesW(linkSourcePath);
    if (attr != INVALID_FILE_ATTRIBUTES) {
	Tcl_SetErrno(EEXIST);
	return -1;
    }

    /*
     * Get the full path referenced by the source file/directory.
     */

    if (!GetFullPathNameW(linkSourcePath, MAX_PATH, tempFileName,
	    &tempFilePart)) {
	/*
	 * Invalid file.
	 */

	TclWinConvertError(GetLastError());
	return -1;
    }

    /*
     * Check the target.
     */

    attr = GetFileAttributesW(linkTargetPath);
    if (attr == INVALID_FILE_ATTRIBUTES) {
	/*
	 * The target doesn't exist.
	 */

	TclWinConvertError(GetLastError());
    } else if ((attr & FILE_ATTRIBUTE_DIRECTORY) == 0) {
	/*
	 * It is a file.
	 */

	if (linkAction & TCL_CREATE_HARD_LINK) {
	    if (CreateHardLinkW(linkSourcePath, linkTargetPath, NULL)) {
		/*
		 * Success!
		 */

		return 0;
	    }

	    TclWinConvertError(GetLastError());
	} else if (linkAction & TCL_CREATE_SYMBOLIC_LINK) {
	    if (!tclWinProcs.createSymbolicLink) {
		/*
		 * Can't symlink files.
		 */
		Tcl_SetErrno(EINVAL);
	    } else if (tclWinProcs.createSymbolicLink(linkSourcePath, linkTargetPath,
		    0x2 /* SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE */)) {
		/*
		 * Success!
		 */

		return 0;
	    } else {
		TclWinConvertError(GetLastError());
	    }
	} else {
	    Tcl_SetErrno(ENODEV);
	}
    } else {
	/*
	 * We've got a directory. Now check whether what we're trying to do is
	 * reasonable.
	 */

	if (linkAction & TCL_CREATE_SYMBOLIC_LINK) {
	    return WinSymLinkDirectory(linkSourcePath, linkTargetPath);

	} else if (linkAction & TCL_CREATE_HARD_LINK) {
	    /*
	     * Can't hard link directories.
	     */

	    Tcl_SetErrno(EISDIR);
	} else {
	    Tcl_SetErrno(ENODEV);
	}
    }
    return -1;
}

/*
 *--------------------------------------------------------------------
 *
 * WinReadLink --
 *
 *	What does 'LinkSource' point to?
 *
 *--------------------------------------------------------------------
 */

static Tcl_Obj *
WinReadLink(
    const WCHAR *linkSourcePath)
{
    WCHAR tempFileName[MAX_PATH];
    WCHAR *tempFilePart;
    DWORD attr;

    /*
     * Get the full path referenced by the target.
     */

    if (!GetFullPathNameW(linkSourcePath, MAX_PATH, tempFileName,
	    &tempFilePart)) {
	/*
	 * Invalid file.
	 */

	TclWinConvertError(GetLastError());
	return NULL;
    }

    /*
     * Make sure source file does exist.
     */

    attr = GetFileAttributesW(linkSourcePath);
    if (attr == INVALID_FILE_ATTRIBUTES) {
	/*
	 * The source doesn't exist.
	 */

	TclWinConvertError(GetLastError());
	return NULL;

    } else if ((attr & FILE_ATTRIBUTE_DIRECTORY) == 0) {
	/*
	 * It is a file - this is not yet supported.
	 */

	Tcl_SetErrno(ENOTDIR);
	return NULL;
    }

    return WinReadLinkDirectory(linkSourcePath);
}

/*
 *--------------------------------------------------------------------
 *
 * WinSymLinkDirectory --
 *
 *	This routine creates a NTFS junction, using the undocumented
 *	FSCTL_SET_REPARSE_POINT structure Win2K uses for mount points and
 *	junctions.
 *
 *	Assumption that linkTargetPath is a valid, existing directory.
 *
 * Returns:
 *	Zero on success.
 *
 *--------------------------------------------------------------------
 */

static int
WinSymLinkDirectory(
    const WCHAR *linkDirPath,
    const WCHAR *linkTargetPath)
{
    DUMMY_REPARSE_BUFFER dummy;
    REPARSE_DATA_BUFFER *reparseBuffer = (REPARSE_DATA_BUFFER *) &dummy;
    int len;
    WCHAR nativeTarget[MAX_PATH];
    WCHAR *loop;

    /*
     * Make the native target name.
     */

    memcpy(nativeTarget, L"\\??\\", 4 * sizeof(WCHAR));
    memcpy(nativeTarget + 4, linkTargetPath,
	   sizeof(WCHAR) * (1+wcslen((WCHAR *) linkTargetPath)));
    len = wcslen(nativeTarget);

    /*
     * We must have backslashes only. This is VERY IMPORTANT. If we have any
     * forward slashes everything appears to work, but the resulting symlink
     * is useless!
     */

    for (loop = nativeTarget; *loop != 0; loop++) {
	if (*loop == '/') {
	    *loop = '\\';
	}
    }
    if ((nativeTarget[len-1] == '\\') && (nativeTarget[len-2] != ':')) {
	nativeTarget[len-1] = 0;
    }

    /*
     * Build the reparse info.
     */

    memset(reparseBuffer, 0, sizeof(DUMMY_REPARSE_BUFFER));
    reparseBuffer->ReparseTag = IO_REPARSE_TAG_MOUNT_POINT;
    reparseBuffer->MountPointReparseBuffer.SubstituteNameLength =
	    wcslen(nativeTarget) * sizeof(WCHAR);
    reparseBuffer->Reserved = 0;
    reparseBuffer->MountPointReparseBuffer.PrintNameLength = 0;
    reparseBuffer->MountPointReparseBuffer.PrintNameOffset =
	    reparseBuffer->MountPointReparseBuffer.SubstituteNameLength
	    + sizeof(WCHAR);
    memcpy(reparseBuffer->MountPointReparseBuffer.PathBuffer, nativeTarget,
	    sizeof(WCHAR)
	    + reparseBuffer->MountPointReparseBuffer.SubstituteNameLength);
    reparseBuffer->ReparseDataLength =
	    reparseBuffer->MountPointReparseBuffer.SubstituteNameLength+12;

    return NativeWriteReparse(linkDirPath, reparseBuffer);
}

/*
 *--------------------------------------------------------------------
 *
 * TclWinSymLinkCopyDirectory --
 *
 *	Copy a Windows NTFS junction. This function assumes that LinkOriginal
 *	exists and is a valid junction point, and that LinkCopy does not
 *	exist.
 *
 * Returns:
 *	Zero on success.
 *
 *--------------------------------------------------------------------
 */

int
TclWinSymLinkCopyDirectory(
    const WCHAR *linkOrigPath,	/* Existing junction - reparse point */
    const WCHAR *linkCopyPath)	/* Will become a duplicate junction */
{
    DUMMY_REPARSE_BUFFER dummy;
    REPARSE_DATA_BUFFER *reparseBuffer = (REPARSE_DATA_BUFFER *) &dummy;

    if (NativeReadReparse(linkOrigPath, reparseBuffer, GENERIC_READ)) {
	return -1;
    }
    return NativeWriteReparse(linkCopyPath, reparseBuffer);
}

/*
 *--------------------------------------------------------------------
 *
 * TclWinSymLinkDelete --
 *
 *	Delete a Windows NTFS junction. Once the junction information is
 *	deleted, the filesystem object becomes an ordinary directory. Unless
 *	'linkOnly' is given, that directory is also removed.
 *
 *	Assumption that LinkOriginal is a valid, existing junction.
 *
 * Returns:
 *	Zero on success.
 *
 *--------------------------------------------------------------------
 */

int
TclWinSymLinkDelete(
    const WCHAR *linkOrigPath,
    int linkOnly)
{
    /*
     * It is a symbolic link - remove it.
     */

    DUMMY_REPARSE_BUFFER dummy;
    REPARSE_DATA_BUFFER *reparseBuffer = (REPARSE_DATA_BUFFER *) &dummy;
    HANDLE hFile;
    DWORD returnedLength;

    memset(reparseBuffer, 0, sizeof(DUMMY_REPARSE_BUFFER));
    reparseBuffer->ReparseTag = IO_REPARSE_TAG_MOUNT_POINT;
    hFile = CreateFileW(linkOrigPath, GENERIC_WRITE, 0, NULL, OPEN_EXISTING,
	    FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, NULL);

    if (hFile != INVALID_HANDLE_VALUE) {
	if (!DeviceIoControl(hFile, FSCTL_DELETE_REPARSE_POINT, reparseBuffer,
		REPARSE_MOUNTPOINT_HEADER_SIZE,NULL,0,&returnedLength,NULL)) {
	    /*
	     * Error setting junction.
	     */

	    TclWinConvertError(GetLastError());
	    CloseHandle(hFile);
	} else {
	    CloseHandle(hFile);
	    if (!linkOnly) {
		RemoveDirectoryW(linkOrigPath);
	    }
	    return 0;
	}
    }
    return -1;
}

/*
 *--------------------------------------------------------------------
 *
 * WinReadLinkDirectory --
 *
 *	This routine reads a NTFS junction, using the undocumented
 *	FSCTL_GET_REPARSE_POINT structure Win2K uses for mount points and
 *	junctions.
 *
 *	Assumption that LinkDirectory is a valid, existing directory.
 *
 * Returns:
 *	A Tcl_Obj with refCount of 1 (i.e. owned by the caller), or NULL if
 *	anything went wrong.
 *
 *	In the future we should enhance this to return a path object rather
 *	than a string.
 *
 *--------------------------------------------------------------------
 */

#if defined (__clang__) || ((__GNUC__)  && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ > 5))))
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Warray-bounds"
#endif

static Tcl_Obj *
WinReadLinkDirectory(
    const WCHAR *linkDirPath)
{
    int attr, len, offset;
    DUMMY_REPARSE_BUFFER dummy;
    REPARSE_DATA_BUFFER *reparseBuffer = (REPARSE_DATA_BUFFER *) &dummy;
    Tcl_Obj *retVal;
    Tcl_DString ds;
    const char *copy;

    attr = GetFileAttributesW(linkDirPath);
    if (!(attr & FILE_ATTRIBUTE_REPARSE_POINT)) {
	goto invalidError;
    }
    if (NativeReadReparse(linkDirPath, reparseBuffer, 0)) {
	return NULL;
    }

    switch (reparseBuffer->ReparseTag) {
    case 0x80000000|IO_REPARSE_TAG_SYMBOLIC_LINK:
    case IO_REPARSE_TAG_SYMBOLIC_LINK:
    case IO_REPARSE_TAG_MOUNT_POINT:
	/*
	 * Certain native path representations on Windows have a special
	 * prefix to indicate that they are to be treated specially. For
	 * example extremely long paths, or symlinks, or volumes mounted
	 * inside directories.
	 *
	 * There is an assumption in this code that 'wide' interfaces are
	 * being used (see tclWin32Dll.c), which is true for the only systems
	 * which support reparse tags at present. If that changes in the
	 * future, this code will have to be generalised.
	 */

	offset = 0;
	if (reparseBuffer->MountPointReparseBuffer.PathBuffer[0] == '\\') {
	    /*
	     * Check whether this is a mounted volume.
	     */

	    if (wcsncmp(reparseBuffer->MountPointReparseBuffer.PathBuffer,
		    L"\\??\\Volume{",11) == 0) {
		char drive;

		/*
		 * There is some confusion between \??\ and \\?\ which we have
		 * to fix here. It doesn't seem very well documented.
		 */

		reparseBuffer->MountPointReparseBuffer.PathBuffer[1] = '\\';

		/*
		 * Check if a corresponding drive letter exists, and use that
		 * if it is found
		 */

		drive = TclWinDriveLetterForVolMountPoint(
			reparseBuffer->MountPointReparseBuffer.PathBuffer);
		if (drive != -1) {
		    char driveSpec[3] = {
			'\0', ':', '\0'
		    };

		    driveSpec[0] = drive;
		    retVal = Tcl_NewStringObj(driveSpec,2);
		    Tcl_IncrRefCount(retVal);
		    return retVal;
		}

		/*
		 * This is actually a mounted drive, which doesn't exists as a
		 * DOS drive letter. This means the path isn't actually a
		 * link, although we partially treat it like one ('file type'
		 * will return 'link'), but then the link will actually just
		 * be treated like an ordinary directory. I don't believe any
		 * serious inconsistency will arise from this, but it is
		 * something to be aware of.
		 */

		goto invalidError;
	    } else if (wcsncmp(reparseBuffer->MountPointReparseBuffer
		    .PathBuffer, L"\\\\?\\",4) == 0) {
		/*
		 * Strip off the prefix.
		 */

		offset = 4;
	    } else if (wcsncmp(reparseBuffer->MountPointReparseBuffer
		    .PathBuffer, L"\\??\\",4) == 0) {
		/*
		 * Strip off the prefix.
		 */

		offset = 4;
	    }
	}

	Tcl_WinTCharToUtf((TCHAR *)
		reparseBuffer->MountPointReparseBuffer.PathBuffer,
		reparseBuffer->MountPointReparseBuffer
		.SubstituteNameLength, &ds);

	copy = Tcl_DStringValue(&ds)+offset;
	len = Tcl_DStringLength(&ds)-offset;
	retVal = Tcl_NewStringObj(copy,len);
	Tcl_IncrRefCount(retVal);
	Tcl_DStringFree(&ds);
	return retVal;
    }

  invalidError:
    Tcl_SetErrno(EINVAL);
    return NULL;
}

#if defined (__clang__) || ((__GNUC__)  && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ > 5))))
#pragma GCC diagnostic pop
#endif

/*
 *--------------------------------------------------------------------
 *
 * NativeReadReparse --
 *
 *	Read the junction/reparse information from a given NTFS directory.
 *
 *	Assumption that linkDirPath is a valid, existing directory.
 *
 * Returns:
 *	Zero on success.
 *
 *--------------------------------------------------------------------
 */

static int
NativeReadReparse(
    const WCHAR *linkDirPath,	/* The junction to read */
    REPARSE_DATA_BUFFER *buffer,/* Pointer to buffer. Cannot be NULL */
    DWORD desiredAccess)
{
    HANDLE hFile;
    DWORD returnedLength;

    hFile = CreateFileW(linkDirPath, desiredAccess, FILE_SHARE_READ, NULL,
	    OPEN_EXISTING,
	    FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, NULL);

    if (hFile == INVALID_HANDLE_VALUE) {
	/*
	 * Error creating directory.
	 */

	TclWinConvertError(GetLastError());
	return -1;
    }

    /*
     * Get the link.
     */

    if (!DeviceIoControl(hFile, FSCTL_GET_REPARSE_POINT, NULL, 0, buffer,
	    sizeof(DUMMY_REPARSE_BUFFER), &returnedLength, NULL)) {
	/*
	 * Error setting junction.
	 */

	TclWinConvertError(GetLastError());
	CloseHandle(hFile);
	return -1;
    }
    CloseHandle(hFile);

    if (!IsReparseTagValid(buffer->ReparseTag)) {
	Tcl_SetErrno(EINVAL);
	return -1;
    }
    return 0;
}

/*
 *--------------------------------------------------------------------
 *
 * NativeWriteReparse --
 *
 *	Write the reparse information for a given directory.
 *
 *	Assumption that LinkDirectory does not exist.
 *
 *--------------------------------------------------------------------
 */

static int
NativeWriteReparse(
    const WCHAR *linkDirPath,
    REPARSE_DATA_BUFFER *buffer)
{
    HANDLE hFile;
    DWORD returnedLength;

    /*
     * Create the directory - it must not already exist.
     */

    if (CreateDirectoryW(linkDirPath, NULL) == 0) {
	/*
	 * Error creating directory.
	 */

	TclWinConvertError(GetLastError());
	return -1;
    }
    hFile = CreateFileW(linkDirPath, GENERIC_WRITE, 0, NULL,
	    OPEN_EXISTING, FILE_FLAG_OPEN_REPARSE_POINT
	    | FILE_FLAG_BACKUP_SEMANTICS, NULL);
    if (hFile == INVALID_HANDLE_VALUE) {
	/*
	 * Error creating directory.
	 */

	TclWinConvertError(GetLastError());
	return -1;
    }

    /*
     * Set the link.
     */

    if (!DeviceIoControl(hFile, FSCTL_SET_REPARSE_POINT, buffer,
	    (DWORD) buffer->ReparseDataLength + REPARSE_MOUNTPOINT_HEADER_SIZE,
	    NULL, 0, &returnedLength, NULL)) {
	/*
	 * Error setting junction.
	 */

	TclWinConvertError(GetLastError());
	CloseHandle(hFile);
	RemoveDirectoryW(linkDirPath);
	return -1;
    }
    CloseHandle(hFile);

    /*
     * We succeeded.
     */

    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * tclWinDebugPanic --
 *
 *	Display a message. If a debugger is present, present it directly to
 *	the debugger, otherwise use a MessageBox.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

MODULE_SCOPE TCL_NORETURN void
tclWinDebugPanic(
    const char *format, ...)
{
#define TCL_MAX_WARN_LEN 1024
    va_list argList;
    char buf[TCL_MAX_WARN_LEN * 3];
    WCHAR msgString[TCL_MAX_WARN_LEN];

    va_start(argList, format);
    vsnprintf(buf, sizeof(buf), format, argList);

    msgString[TCL_MAX_WARN_LEN-1] = '\0';
    MultiByteToWideChar(CP_UTF8, 0, buf, -1, msgString, TCL_MAX_WARN_LEN);

    /*
     * Truncate MessageBox string if it is too long to not overflow the screen
     * and cause possible oversized window error.
     */

    if (msgString[TCL_MAX_WARN_LEN-1] != '\0') {
	memcpy(msgString + (TCL_MAX_WARN_LEN - 5), L" ...", 5 * sizeof(WCHAR));
    }
    if (IsDebuggerPresent()) {
	OutputDebugStringW(msgString);
    } else {
	MessageBeep(MB_ICONEXCLAMATION);
	MessageBoxW(NULL, msgString, L"Fatal Error",
		MB_ICONSTOP | MB_OK | MB_TASKMODAL | MB_SETFOREGROUND);
    }
#if defined(__GNUC__)
    __builtin_trap();
#elif defined(_WIN64)
    __debugbreak();
#elif defined(_MSC_VER) && defined (_M_IX86)
    _asm {int 3}
#else
    DebugBreak();
#endif
    abort();
}

/*
 *---------------------------------------------------------------------------
 *
 * TclpFindExecutable --
 *
 *	This function computes the absolute path name of the current
 *	application.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The computed path is stored.
 *
 *---------------------------------------------------------------------------
 */

void
TclpFindExecutable(
    const char *argv0)		/* If NULL, install PanicMessageBox, otherwise
				 * ignore. */
{
    WCHAR wName[MAX_PATH];
    char name[MAX_PATH * 3];

    /*
     * Under Windows we ignore argv0, and return the path for the file used to
     * create this process. Only if it is NULL, install a new panic handler.
     */

    if (argv0 == NULL) {
	Tcl_SetPanicProc(tclWinDebugPanic);
    }

    GetModuleFileNameW(NULL, wName, sizeof(wName)/sizeof(WCHAR));
    WideCharToMultiByte(CP_UTF8, 0, wName, -1, name, sizeof(name), NULL, NULL);
    TclWinNoBackslash(name);
    TclSetObjNameOfExecutable(Tcl_NewStringObj(name, -1), NULL);
}

/*
 *----------------------------------------------------------------------
 *
 * TclpMatchInDirectory --
 *
 *	This routine is used by the globbing code to search a directory for
 *	all files which match a given pattern.
 *
 * Results:
 *	The return value is a standard Tcl result indicating whether an error
 *	occurred in globbing. Errors are left in interp, good results are
 *	lappended to resultPtr (which must be a valid object).
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
TclpMatchInDirectory(
    Tcl_Interp *interp,		/* Interpreter to receive errors. */
    Tcl_Obj *resultPtr,		/* List object to lappend results. */
    Tcl_Obj *pathPtr,		/* Contains path to directory to search. */
    const char *pattern,	/* Pattern to match against. */
    Tcl_GlobTypeData *types)	/* Object containing list of acceptable types.
				 * May be NULL. In particular the directory
				 * flag is very important. */
{
    const WCHAR *native;

    if (types != NULL && types->type == TCL_GLOB_TYPE_MOUNT) {
	/*
	 * The native filesystem never adds mounts.
	 */

	return TCL_OK;
    }

    if (pattern == NULL || (*pattern == '\0')) {
	Tcl_Obj *norm = Tcl_FSGetNormalizedPath(NULL, pathPtr);

	if (norm != NULL) {
	    /*
	     * Match a single file directly.
	     */

	    int len;
	    DWORD attr;
	    WIN32_FILE_ATTRIBUTE_DATA data;
	    const char *str = Tcl_GetStringFromObj(norm,&len);

	    native = (WCHAR *)Tcl_FSGetNativePath(pathPtr);

	    if (GetFileAttributesExW(native,
		    GetFileExInfoStandard, &data) != TRUE) {
		return TCL_OK;
	    }
	    attr = data.dwFileAttributes;

	    if (NativeMatchType(WinIsDrive(str,len), attr, native, types)) {
		Tcl_ListObjAppendElement(interp, resultPtr, pathPtr);
	    }
	}
	return TCL_OK;
    } else {
	DWORD attr;
	HANDLE handle;
	WIN32_FIND_DATAW data;
	const char *dirName;	/* UTF-8 dir name, later with pattern
				 * appended. */
	int dirLength;
	int matchSpecialDots;
	Tcl_DString ds;		/* Native encoding of dir, also used
				 * temporarily for other things. */
	Tcl_DString dsOrig;	/* UTF-8 encoding of dir. */
	Tcl_Obj *fileNamePtr;
	char lastChar;

	/*
	 * Get the normalized path representation (the main thing is we dont
	 * want any '~' sequences).
	 */

	fileNamePtr = Tcl_FSGetNormalizedPath(interp, pathPtr);
	if (fileNamePtr == NULL) {
	    return TCL_ERROR;
	}

	/*
	 * Verify that the specified path exists and is actually a directory.
	 */

	native = (const WCHAR *)Tcl_FSGetNativePath(pathPtr);
	if (native == NULL) {
	    return TCL_OK;
	}
	attr = GetFileAttributesW(native);

	if ((attr == INVALID_FILE_ATTRIBUTES)
	    || ((attr & FILE_ATTRIBUTE_DIRECTORY) == 0)) {
	    return TCL_OK;
	}

	/*
	 * Build up the directory name for searching, including a trailing
	 * directory separator.
	 */

	Tcl_DStringInit(&dsOrig);
	dirName = Tcl_GetStringFromObj(fileNamePtr, &dirLength);
	Tcl_DStringAppend(&dsOrig, dirName, dirLength);

	lastChar = dirName[dirLength -1];
	if ((lastChar != '\\') && (lastChar != '/') && (lastChar != ':')) {
	    TclDStringAppendLiteral(&dsOrig, "/");
	    dirLength++;
	}
	dirName = Tcl_DStringValue(&dsOrig);

	/*
	 * We need to check all files in the directory, so we append '*.*' to
	 * the path, unless the pattern we've been given is rather simple,
	 * when we can use that instead.
	 */

	if (strpbrk(pattern, "[]\\") == NULL) {
	    /*
	     * The pattern is a simple one containing just '*' and/or '?'.
	     * This means we can get the OS to help us, by passing it the
	     * pattern.
	     */

	    dirName = Tcl_DStringAppend(&dsOrig, pattern, -1);
	} else {
	    dirName = TclDStringAppendLiteral(&dsOrig, "*.*");
	}

	native = (WCHAR *)Tcl_WinUtfToTChar(dirName, -1, &ds);
	if ((types == NULL) || (types->type != TCL_GLOB_TYPE_DIR)) {
	    handle = FindFirstFileW(native, &data);
	} else {
	    /*
	     * We can be more efficient, for pure directory requests.
	     */

	    handle = FindFirstFileExW(native,
		    FindExInfoStandard, &data,
		    FindExSearchLimitToDirectories, NULL, 0);
	}

	if (handle == INVALID_HANDLE_VALUE) {
	    DWORD err = GetLastError();

	    Tcl_DStringFree(&ds);
	    if (err == ERROR_FILE_NOT_FOUND) {
		/*
		 * We used our 'pattern' above, and matched nothing. This
		 * means we just return TCL_OK, indicating no results found.
		 */

		Tcl_DStringFree(&dsOrig);
		return TCL_OK;
	    }

	    TclWinConvertError(err);
	    if (interp != NULL) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"couldn't read directory \"%s\": %s",
			Tcl_DStringValue(&dsOrig), Tcl_PosixError(interp)));
	    }
	    Tcl_DStringFree(&dsOrig);
	    return TCL_ERROR;
	}
	Tcl_DStringFree(&ds);

	/*
	 * We may use this later, so we must restore it to its length
	 * including the directory delimiter.
	 */

	Tcl_DStringSetLength(&dsOrig, dirLength);

	/*
	 * Check to see if the pattern should match the special . and
	 * .. names, referring to the current directory, or the directory
	 * above. We need a special check for this because paths beginning
	 * with a dot are not considered hidden on Windows, and so otherwise a
	 * relative glob like 'glob -join * *' will actually return
	 * './. ../..' etc.
	 */

	if ((pattern[0] == '.')
		|| ((pattern[0] == '\\') && (pattern[1] == '.'))) {
	    matchSpecialDots = 1;
	} else {
	    matchSpecialDots = 0;
	}

	/*
	 * Now iterate over all of the files in the directory, starting with
	 * the first one we found.
	 */

	do {
	    const char *utfname;
	    int checkDrive = 0, isDrive;

	    native = data.cFileName;
	    attr = data.dwFileAttributes;
	    utfname = Tcl_WinTCharToUtf((TCHAR *)native, -1, &ds);

	    if (!matchSpecialDots) {
		/*
		 * If it is exactly '.' or '..' then we ignore it.
		 */

		if ((utfname[0] == '.') && (utfname[1] == '\0'
			|| (utfname[1] == '.' && utfname[2] == '\0'))) {
		    Tcl_DStringFree(&ds);
		    continue;
		}
	    } else if (utfname[0] == '.' && utfname[1] == '.'
		    && utfname[2] == '\0') {
		/*
		 * Have to check if this is a drive below, so we can correctly
		 * match 'hidden' and not hidden files.
		 */

		checkDrive = 1;
	    }

	    /*
	     * Check to see if the file matches the pattern. Note that we are
	     * ignoring the case sensitivity flag because Windows doesn't
	     * honor case even if the volume is case sensitive. If the volume
	     * also doesn't preserve case, then we previously returned the
	     * lower case form of the name. This didn't seem quite right since
	     * there are non-case-preserving volumes that actually return
	     * mixed case. So now we are returning exactly what we get from
	     * the system.
	     */

	    if (Tcl_StringCaseMatch(utfname, pattern, 1)) {
		/*
		 * If the file matches, then we need to process the remainder
		 * of the path.
		 */

		if (checkDrive) {
		    const char *fullname = Tcl_DStringAppend(&dsOrig, utfname,
			    Tcl_DStringLength(&ds));

		    isDrive = WinIsDrive(fullname, Tcl_DStringLength(&dsOrig));
		    Tcl_DStringSetLength(&dsOrig, dirLength);
		} else {
		    isDrive = 0;
		}
		if (NativeMatchType(isDrive, attr, native, types)) {
		    Tcl_ListObjAppendElement(interp, resultPtr,
			    TclNewFSPathObj(pathPtr, utfname,
				    Tcl_DStringLength(&ds)));
		}
	    }

	    /*
	     * Free ds here to ensure that native is valid above.
	     */

	    Tcl_DStringFree(&ds);
	} while (FindNextFileW(handle, &data) == TRUE);

	FindClose(handle);
	Tcl_DStringFree(&dsOrig);
	return TCL_OK;
    }
}

/*
 * Does the given path represent a root volume? We need this special case
 * because for NTFS root volumes, the getFileAttributesProc returns a 'hidden'
 * attribute when it should not.
 */

static int
WinIsDrive(
    const char *name,		/* Name (UTF-8) */
    size_t len)			/* Length of name */
{
    int remove = 0;

    while (len > 4) {
	if ((name[len-1] != '.' || name[len-2] != '.')
		|| (name[len-3] != '/' && name[len-3] != '\\')) {
	    /*
	     * We don't have '/..' at the end.
	     */

	    if (remove == 0) {
		break;
	    }
	    remove--;
	    while (len > 0) {
		len--;
		if (name[len] == '/' || name[len] == '\\') {
		    break;
		}
	    }
	    if (len < 4) {
		len++;
		break;
	    }
	} else {
	    /*
	     * We do have '/..'
	     */

	    len -= 3;
	    remove++;
	}
    }

    if (len < 4) {
	if (len == 0) {
	    /*
	     * Not sure if this is possible, but we pass it on anyway.
	     */
	} else if (len == 1 && (name[0] == '/' || name[0] == '\\')) {
	    /*
	     * Path is pointing to the root volume.
	     */

	    return 1;
	} else if ((name[1] == ':')
		   && (len == 2 || (name[2] == '/' || name[2] == '\\'))) {
	    /*
	     * Path is of the form 'x:' or 'x:/' or 'x:\'
	     */

	    return 1;
	}
    }

    return 0;
}

/*
 * Does the given path represent a reserved window path name? If not return 0,
 * if true, return the number of characters of the path that we actually want
 * (not any trailing :).
 */

static int
WinIsReserved(
    const char *path)		/* Path in UTF-8 */
{
    if ((path[0] == 'c' || path[0] == 'C')
	    && (path[1] == 'o' || path[1] == 'O')) {
	if ((path[2] == 'm' || path[2] == 'M')
		&& path[3] >= '1' && path[3] <= '9') {
	    /*
	     * May have match for 'com[1-9]:?', which is a serial port.
	     */

	    if (path[4] == '\0') {
		return 4;
	    } else if (path[4] == ':' && path[5] == '\0') {
		return 4;
	    }
	} else if ((path[2] == 'n' || path[2] == 'N') && path[3] == '\0') {
	    /*
	     * Have match for 'con'
	     */

	    return 3;
	}

    } else if ((path[0] == 'l' || path[0] == 'L')
	    && (path[1] == 'p' || path[1] == 'P')
	    && (path[2] == 't' || path[2] == 'T')) {
	if (path[3] >= '1' && path[3] <= '9') {
	    /*
	     * May have match for 'lpt[1-9]:?'
	     */

	    if (path[4] == '\0') {
		return 4;
	    } else if (path[4] == ':' && path[5] == '\0') {
		return 4;
	    }
	}

    } else if (!strcasecmp(path, "prn") || !strcasecmp(path, "nul")
	    || !strcasecmp(path, "aux")) {
	/*
	 * Have match for 'prn', 'nul' or 'aux'.
	 */

	return 3;
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * NativeMatchType --
 *
 *	This function needs a special case for a path which is a root volume,
 *	because for NTFS root volumes, the getFileAttributesProc returns a
 *	'hidden' attribute when it should not.
 *
 *	We never make any calls to a 'get attributes' routine here, since we
 *	have arranged things so that our caller already knows such
 *	information.
 *
 * Results:
 *	0 = file doesn't match
 *	1 = file matches
 *
 *----------------------------------------------------------------------
 */

static int
NativeMatchType(
    int isDrive,		/* Is this a drive. */
    DWORD attr,			/* We already know the attributes for the
				 * file. */
    const WCHAR *nativeName,	/* Native path to check. */
    Tcl_GlobTypeData *types)	/* Type description to match against. */
{
    /*
     * 'attr' represents the attributes of the file, but we only want to
     * retrieve this info if it is absolutely necessary because it is an
     * expensive call. Unfortunately, to deal with hidden files properly, we
     * must always retrieve it.
     */

    if (types == NULL) {
	/*
	 * If invisible, don't return the file.
	 */

	return !(attr & FILE_ATTRIBUTE_HIDDEN && !isDrive);
    }

    if (attr & FILE_ATTRIBUTE_HIDDEN && !isDrive) {
	/*
	 * If invisible.
	 */

	if ((types->perm == 0) || !(types->perm & TCL_GLOB_PERM_HIDDEN)) {
	    return 0;
	}
    } else {
	/*
	 * Visible.
	 */

	if (types->perm & TCL_GLOB_PERM_HIDDEN) {
	    return 0;
	}
    }

    if (types->perm != 0) {
	if (((types->perm & TCL_GLOB_PERM_RONLY) &&
		    !(attr & FILE_ATTRIBUTE_READONLY)) ||
		((types->perm & TCL_GLOB_PERM_R) &&
		    (0 /* File exists => R_OK on Windows */)) ||
		((types->perm & TCL_GLOB_PERM_W) &&
		    (attr & FILE_ATTRIBUTE_READONLY)) ||
		((types->perm & TCL_GLOB_PERM_X) &&
		    (!(attr & FILE_ATTRIBUTE_DIRECTORY)
		    && !NativeIsExec(nativeName)))) {
	    return 0;
	}
    }

    if ((types->type & TCL_GLOB_TYPE_DIR)
	    && (attr & FILE_ATTRIBUTE_DIRECTORY)) {
	/*
	 * Quicker test for directory, which is a common case.
	 */

	return 1;

    } else if (types->type != 0) {
	unsigned short st_mode;
	int isExec = NativeIsExec(nativeName);

	st_mode = NativeStatMode(attr, 0, isExec);

	/*
	 * In order bcdpfls as in 'find -t'
	 */

	if (((types->type&TCL_GLOB_TYPE_BLOCK)    && S_ISBLK(st_mode)) ||
		((types->type&TCL_GLOB_TYPE_CHAR) && S_ISCHR(st_mode)) ||
		((types->type&TCL_GLOB_TYPE_DIR)  && S_ISDIR(st_mode)) ||
		((types->type&TCL_GLOB_TYPE_PIPE) && S_ISFIFO(st_mode)) ||
#ifdef S_ISSOCK
		((types->type&TCL_GLOB_TYPE_SOCK) && S_ISSOCK(st_mode)) ||
#endif
		((types->type&TCL_GLOB_TYPE_FILE) && S_ISREG(st_mode))) {
	    /*
	     * Do nothing - this file is ok.
	     */
	} else {
#ifdef S_ISLNK
	    if (types->type & TCL_GLOB_TYPE_LINK) {
		st_mode = NativeStatMode(attr, 1, isExec);
		if (S_ISLNK(st_mode)) {
		    return 1;
		}
	    }
#endif /* S_ISLNK */
	    return 0;
	}
    }
    return 1;
}

/*
 *----------------------------------------------------------------------
 *
 * TclpGetUserHome --
 *
 *	This function takes the passed in user name and finds the
 *	corresponding home directory specified in the password file.
 *
 * Results:
 *	The result is a pointer to a string specifying the user's home
 *	directory, or NULL if the user's home directory could not be
 *	determined. Storage for the result string is allocated in bufferPtr;
 *	the caller must call Tcl_DStringFree() when the result is no longer
 *	needed.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

const char *
TclpGetUserHome(
    const char *name,		/* User name for desired home directory. */
    Tcl_DString *bufferPtr)	/* Uninitialized or free DString filled with
				 * name of user's home directory. */
{
    char *result = NULL;
    USER_INFO_1 *uiPtr;
    Tcl_DString ds;
    int nameLen = -1;
    int rc = 0;
    const char *domain;
    WCHAR *wName, *wHomeDir, *wDomain;

    Tcl_DStringInit(bufferPtr);

    wDomain = NULL;
    domain = Tcl_UtfFindFirst(name, '@');
    if (domain == NULL) {
	const char *ptr;

        /*
         * Treat the current user as a special case because the general case
         * below does not properly retrieve the path. The NetUserGetInfo
         * call returns an empty path and the code defaults to the user's
         * name in the profiles directory. On modern Windows systems, this
         * is generally wrong as when the account is a Microsoft account,
         * for example abcdefghi@outlook.com, the directory name is
         * abcde and not abcdefghi.
         *
         * Note we could have just used env(USERPROFILE) here but
         * the intent is to retrieve (as on Unix) the system's view
         * of the home irrespective of environment settings of HOME
         * and USERPROFILE.
         *
         * Fixing this for the general user needs more investigating but
         * at least for the current user we can use a direct call.
         */
	ptr = TclpGetUserName(&ds);
	if (ptr != NULL && strcasecmp(name, ptr) == 0) {
	    HANDLE hProcess;
	    WCHAR buf[MAX_PATH];
	    DWORD nChars = sizeof(buf) / sizeof(buf[0]);
	    /* Sadly GetCurrentProcessToken not in Win 7 so slightly longer */
	    hProcess = GetCurrentProcess(); /* Need not be closed */
	    if (hProcess) {
		HANDLE hToken;
		if (OpenProcessToken(hProcess, TOKEN_QUERY, &hToken)) {
		    if (GetUserProfileDirectoryW(hToken, buf, &nChars)) {
			Tcl_WinTCharToUtf((TCHAR *)buf,
				(nChars-1)*sizeof(WCHAR), bufferPtr);
			result = Tcl_DStringValue(bufferPtr);
			rc = 1;
		    }
		    CloseHandle(hToken);
		}
	    }
	}
	Tcl_DStringFree(&ds);
    } else {
	wName = (WCHAR *)Tcl_WinUtfToTChar(domain + 1, -1, &ds);
	rc = NetGetDCName(NULL, wName, (LPBYTE *) &wDomain);
	Tcl_DStringFree(&ds);
	nameLen = domain - name;
    }
    if (rc == 0) {
	wName = (WCHAR *)Tcl_WinUtfToTChar(name, nameLen, &ds);
	while (NetUserGetInfo(wDomain, wName, 1, (LPBYTE *) &uiPtr) != 0) {
	    /*
	     * User does not exist; if domain was not specified, try again
	     * using current domain.
	     */

	    rc = 1;
	    if (domain != NULL) {
		break;
	    }

	    /*
	     * Get current domain
	     */

	    rc = NetGetDCName(NULL, NULL, (LPBYTE *) &wDomain);
	    if (rc != 0) {
		break;
	    }
	    domain = (const char *)INT2PTR(-1); /* repeat once */
	}
	if (rc == 0) {
	    DWORD i, size = MAX_PATH;

	    wHomeDir = uiPtr->usri1_home_dir;
	    if ((wHomeDir != NULL) && (wHomeDir[0] != '\0')) {
		size = lstrlenW(wHomeDir);
		Tcl_WinTCharToUtf((TCHAR *)wHomeDir, size*sizeof(WCHAR), bufferPtr);
	    } else {
		WCHAR buf[MAX_PATH];
		/*
		 * User exists but has no home dir. Return
		 * "{GetProfilesDirectory}/<user>".
		 */

		GetProfilesDirectoryW(buf, &size);
		Tcl_WinTCharToUtf((TCHAR *)buf, (size-1)*sizeof(WCHAR), bufferPtr);
		Tcl_DStringAppend(bufferPtr, "/", 1);
		Tcl_DStringAppend(bufferPtr, name, nameLen);
	    }
	    result = Tcl_DStringValue(bufferPtr);

	    /*
	     * Be sure we return normalized path
	     */

	    for (i = 0; i < size; ++i) {
		if (result[i] == '\\') {
		    result[i] = '/';
		}
	    }
	    NetApiBufferFree((void *) uiPtr);
	}
	Tcl_DStringFree(&ds);
    }
    if (wDomain != NULL) {
	NetApiBufferFree((void *) wDomain);
    }

    return result;
}

/*
 *---------------------------------------------------------------------------
 *
 * NativeAccess --
 *
 *	This function replaces the library version of access(), fixing the
 *	following bugs:
 *
 *	1. access() returns that all files have execute permission.
 *
 * Results:
 *	See access documentation.
 *
 * Side effects:
 *	See access documentation.
 *
 *---------------------------------------------------------------------------
 */

static int
NativeAccess(
    const WCHAR *nativePath,	/* Path of file to access, native encoding. */
    int mode)			/* Permission setting. */
{
    DWORD attr;

    attr = GetFileAttributesW(nativePath);

    if (attr == INVALID_FILE_ATTRIBUTES) {
	/*
	 * File might not exist.
	 */

	DWORD lasterror = GetLastError();
	if (lasterror != ERROR_SHARING_VIOLATION) {
	    TclWinConvertError(lasterror);
	    return -1;
	}
    }

    if (mode == F_OK) {
	/*
	 * File exists, nothing else to check.
	 */

	return 0;
    }

    /*
     * If it's not a directory (assume file), do several fast checks:
     */

    if (!(attr & FILE_ATTRIBUTE_DIRECTORY)) {
	/*
	 * If the attributes say this is not writable at all.  The file is a
	 * regular file (i.e., not a directory), then the file is not
	 * writable, full stop.  For directories, the read-only bit is
	 * (mostly) ignored by Windows, so we can't ascertain anything about
	 * directory access from the attrib data.  However, if we have the
	 * advanced 'getFileSecurityProc', then more robust ACL checks will be
	 * done below.
	 */

	if ((mode & W_OK) && (attr & FILE_ATTRIBUTE_READONLY)) {
	    Tcl_SetErrno(EACCES);
	    return -1;
	}

	/*
	 * If doesn't have the correct extension, it can't be executable
	 */

	if ((mode & X_OK) && !NativeIsExec(nativePath)) {
	    Tcl_SetErrno(EACCES);
	    return -1;
	}

	/*
	 * Special case for read/write/executable check on file
	 */

	if ((mode & (R_OK|W_OK|X_OK)) && !(mode & ~(R_OK|W_OK|X_OK))) {
	    DWORD mask = 0;
	    HANDLE hFile;

	    if (mode & R_OK) {
		mask |= GENERIC_READ;
	    }
	    if (mode & W_OK) {
		mask |= GENERIC_WRITE;
	    }
	    if (mode & X_OK) {
		mask |= GENERIC_EXECUTE;
	    }

	    hFile = CreateFileW(nativePath, mask,
		    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
		    NULL, OPEN_EXISTING, FILE_FLAG_NO_BUFFERING, NULL);
	    if (hFile != INVALID_HANDLE_VALUE) {
		CloseHandle(hFile);
		return 0;
	    }

	    /*
	     * Fast exit if access was denied
	     */

	    if (GetLastError() == ERROR_ACCESS_DENIED) {
		Tcl_SetErrno(EACCES);
		return -1;
	    }
	}

	/*
	 * We cannot verify the access fast, check it below using security
	 * info.
	 */
    }

    /*
     * It looks as if the permissions are ok, but if we are on NT, 2000 or XP,
     * we have a more complex permissions structure so we try to check that.
     * The code below is remarkably complex for such a simple thing as finding
     * what permissions the OS has set for a file.
     */

    {
	SECURITY_DESCRIPTOR *sdPtr = NULL;
	unsigned long size;
	PSID pSid = 0;
	BOOL SidDefaulted;
	SID_IDENTIFIER_AUTHORITY samba_unmapped = {{0, 0, 0, 0, 0, 22}};
	GENERIC_MAPPING genMap;
	HANDLE hToken = NULL;
	DWORD desiredAccess = 0, grantedAccess = 0;
	BOOL accessYesNo = FALSE;
	PRIVILEGE_SET privSet;
	DWORD privSetSize = sizeof(PRIVILEGE_SET);
	int error;

	/*
	 * First find out how big the buffer needs to be.
	 */

	size = 0;
	GetFileSecurityW(nativePath,
		OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION
		| DACL_SECURITY_INFORMATION | LABEL_SECURITY_INFORMATION,
		0, 0, &size);

	/*
	 * Should have failed with ERROR_INSUFFICIENT_BUFFER
	 */

	error = GetLastError();
	if (error != ERROR_INSUFFICIENT_BUFFER) {
	    /*
	     * Most likely case is ERROR_ACCESS_DENIED, which we will convert
	     * to EACCES - just what we want!
	     */

	    TclWinConvertError((DWORD) error);
	    return -1;
	}

	/*
	 * Now size contains the size of buffer needed.
	 */

	sdPtr = (SECURITY_DESCRIPTOR *) HeapAlloc(GetProcessHeap(), 0, size);

	if (sdPtr == NULL) {
	    goto accessError;
	}

	/*
	 * Call GetFileSecurityW() for real.
	 */

	if (!GetFileSecurityW(nativePath,
		OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION
		| DACL_SECURITY_INFORMATION | LABEL_SECURITY_INFORMATION,
		sdPtr, size, &size)) {
	    /*
	     * Error getting owner SD
	     */

	    goto accessError;
	}

	/*
	 * As of Samba 3.0.23 (10-Jul-2006), unmapped users and groups are
	 * assigned to SID domains S-1-22-1 and S-1-22-2, where "22" is the
	 * top-level authority.	 If the file owner and group is unmapped then
	 * the ACL access check below will only test against world access,
	 * which is likely to be more restrictive than the actual access
	 * restrictions.  Since the ACL tests are more likely wrong than
	 * right, skip them.  Moreover, the unix owner access permissions are
	 * usually mapped to the Windows attributes, so if the user is the
	 * file owner then the attrib checks above are correct (as far as they
	 * go).
	 */

	if(!GetSecurityDescriptorOwner(sdPtr,&pSid,&SidDefaulted) ||
	   memcmp(GetSidIdentifierAuthority(pSid),&samba_unmapped,
		  sizeof(SID_IDENTIFIER_AUTHORITY))==0) {
	    HeapFree(GetProcessHeap(), 0, sdPtr);
	    return 0; /* Attrib tests say access allowed. */
	}

	/*
	 * Perform security impersonation of the user and open the resulting
	 * thread token.
	 */

	if (!ImpersonateSelf(SecurityImpersonation)) {
	    /*
	     * Unable to perform security impersonation.
	     */

	    goto accessError;
	}
	if (!OpenThreadToken(GetCurrentThread(),
		TOKEN_DUPLICATE | TOKEN_QUERY, FALSE, &hToken)) {
	    /*
	     * Unable to get current thread's token.
	     */

	    goto accessError;
	}

	RevertToSelf();

	/*
	 * Setup desiredAccess according to the access privileges we are
	 * checking.
	 */

	if (mode & R_OK) {
	    desiredAccess |= FILE_GENERIC_READ;
	}
	if (mode & W_OK) {
	    desiredAccess |= FILE_GENERIC_WRITE;
	}
	if (mode & X_OK) {
	    desiredAccess |= FILE_GENERIC_EXECUTE;
	}

	memset(&genMap, 0x0, sizeof(GENERIC_MAPPING));
	genMap.GenericRead = FILE_GENERIC_READ;
	genMap.GenericWrite = FILE_GENERIC_WRITE;
	genMap.GenericExecute = FILE_GENERIC_EXECUTE;
	genMap.GenericAll = FILE_ALL_ACCESS;

	/*
	 * Perform access check using the token.
	 */

	if (!AccessCheck(sdPtr, hToken, desiredAccess,
		&genMap, &privSet, &privSetSize, &grantedAccess,
		&accessYesNo)) {
	    /*
	     * Unable to perform access check.
	     */

	accessError:
	    TclWinConvertError(GetLastError());
	    if (sdPtr != NULL) {
		HeapFree(GetProcessHeap(), 0, sdPtr);
	    }
	    if (hToken != NULL) {
		CloseHandle(hToken);
	    }
	    return -1;
	}

	/*
	 * Clean up.
	 */

	HeapFree(GetProcessHeap(), 0, sdPtr);
	CloseHandle(hToken);
	if (!accessYesNo) {
	    Tcl_SetErrno(EACCES);
	    return -1;
	}

    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * NativeIsExec --
 *
 *	Determines if a path is executable. On windows this is simply defined
 *	by whether the path ends in a standard executable extension.
 *
 * Results:
 *	1 = executable, 0 = not.
 *
 *----------------------------------------------------------------------
 */

static int
NativeIsExec(
    const WCHAR *path)
{
    size_t len = wcslen(path);

    if (len < 5) {
	return 0;
    }

    if (path[len-4] != '.') {
	return 0;
    }

    path += len-3;
    if ((_wcsicmp(path, L"exe") == 0)
	    || (_wcsicmp(path, L"com") == 0)
	    || (_wcsicmp(path, L"cmd") == 0)
	    || (_wcsicmp(path, L"bat") == 0)) {
	return 1;
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * TclpObjChdir --
 *
 *	This function replaces the library version of chdir().
 *
 * Results:
 *	See chdir() documentation.
 *
 * Side effects:
 *	See chdir() documentation.
 *
 *----------------------------------------------------------------------
 */

int
TclpObjChdir(
    Tcl_Obj *pathPtr)	/* Path to new working directory. */
{
    int result;
    const WCHAR *nativePath;

    nativePath = (const WCHAR *)Tcl_FSGetNativePath(pathPtr);

    if (!nativePath) {
	return -1;
    }
    result = SetCurrentDirectoryW(nativePath);

    if (result == 0) {
	TclWinConvertError(GetLastError());
	return -1;
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * TclpGetCwd --
 *
 *	This function replaces the library version of getcwd(). (Obsolete
 *	function, only retained for old extensions which may call it
 *	directly).
 *
 * Results:
 *	The result is a pointer to a string specifying the current directory,
 *	or NULL if the current directory could not be determined. If NULL is
 *	returned, an error message is left in the interp's result. Storage for
 *	the result string is allocated in bufferPtr; the caller must call
 *	Tcl_DStringFree() when the result is no longer needed.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

const char *
TclpGetCwd(
    Tcl_Interp *interp,		/* If non-NULL, used for error reporting. */
    Tcl_DString *bufferPtr)	/* Uninitialized or free DString filled with
				 * name of current directory. */
{
    WCHAR buffer[MAX_PATH];
    char *p;
    WCHAR *native;

    if (GetCurrentDirectoryW(MAX_PATH, buffer) == 0) {
	TclWinConvertError(GetLastError());
	if (interp != NULL) {
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "error getting working directory name: %s",
		    Tcl_PosixError(interp)));
	}
	return NULL;
    }

    /*
     * Watch for the weird Windows c:\\UNC syntax.
     */

    native = (WCHAR *) buffer;
    if ((native[0] != '\0') && (native[1] == ':')
	    && (native[2] == '\\') && (native[3] == '\\')) {
	native += 2;
    }
    Tcl_WinTCharToUtf((TCHAR *) native, -1, bufferPtr);

    /*
     * Convert to forward slashes for easier use in scripts.
     */

    for (p = Tcl_DStringValue(bufferPtr); *p != '\0'; p++) {
	if (*p == '\\') {
	    *p = '/';
	}
    }
    return Tcl_DStringValue(bufferPtr);
}

int
TclpObjStat(
    Tcl_Obj *pathPtr,		/* Path of file to stat. */
    Tcl_StatBuf *statPtr)	/* Filled with results of stat call. */
{
    /*
     * Ensure correct file sizes by forcing the OS to write any pending data
     * to disk. This is done only for channels which are dirty, i.e. have been
     * written to since the last flush here.
     */

    TclWinFlushDirtyChannels();

    return NativeStat((const WCHAR *)Tcl_FSGetNativePath(pathPtr), statPtr, 0);
}

/*
 *----------------------------------------------------------------------
 *
 * NativeStat --
 *
 *	This function replaces the library version of stat(), fixing the
 *	following bugs:
 *
 *	1. stat("c:") returns an error.
 *	2. Borland stat() return time in GMT instead of localtime.
 *	3. stat("\\server\mount") would return error.
 *	4. Accepts slashes or backslashes.
 *	5. st_dev and st_rdev were wrong for UNC paths.
 *
 * Results:
 *	See stat documentation.
 *
 * Side effects:
 *	See stat documentation.
 *
 *----------------------------------------------------------------------
 */

static int
NativeStat(
    const WCHAR *nativePath,	/* Path of file to stat */
    Tcl_StatBuf *statPtr,	/* Filled with results of stat call. */
    int checkLinks)		/* If non-zero, behave like 'lstat' */
{
    DWORD attr;
    int dev, nlink = 1;
    unsigned short mode;
    unsigned int inode = 0;
    HANDLE fileHandle;
    DWORD fileType = FILE_TYPE_UNKNOWN;

    /*
     * If we can use 'createFile' on this, then we can use the resulting
     * fileHandle to read more information (nlink, ino) than we can get from
     * other attributes reading APIs. If not, then we try to fall back on the
     * 'getFileAttributesExProc', and if that isn't available, then on even
     * simpler routines.
     *
     * Special consideration must be given to Windows hard-coded names like
     * CON, NULL, COM1, LPT1 etc. For these, we still need to do the
     * CreateFile as some may not exist (e.g. there is no CON in wish by
     * default). However the subsequent GetFileInformationByHandle will
     * fail. We do a WinIsReserved to see if it is one of the special names,
     * and if successful, mock up a BY_HANDLE_FILE_INFORMATION structure.
     */

    fileHandle = CreateFileW(nativePath, GENERIC_READ,
	    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
	    NULL, OPEN_EXISTING,
	    FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT, NULL);

    if (fileHandle != INVALID_HANDLE_VALUE) {
	BY_HANDLE_FILE_INFORMATION data;

	if (GetFileInformationByHandle(fileHandle,&data) != TRUE) {
            fileType = GetFileType(fileHandle);
            CloseHandle(fileHandle);
            if (fileType != FILE_TYPE_CHAR && fileType != FILE_TYPE_DISK) {
                Tcl_SetErrno(ENOENT);
                return -1;
            }

            /*
	     * Mock up the expected structure
	     */

            memset(&data, 0, sizeof(data));
            statPtr->st_atime = 0;
            statPtr->st_mtime = 0;
            statPtr->st_ctime = 0;
        } else {
            CloseHandle(fileHandle);
            statPtr->st_atime = ToCTime(data.ftLastAccessTime);
            statPtr->st_mtime = ToCTime(data.ftLastWriteTime);
            statPtr->st_ctime = ToCTime(data.ftCreationTime);
        }
	attr = data.dwFileAttributes;
	statPtr->st_size = ((Tcl_WideInt)data.nFileSizeLow) |
		(((Tcl_WideInt)data.nFileSizeHigh) << 32);

	/*
	 * On Unix, for directories, nlink apparently depends on the number of
	 * files in the directory.  We could calculate that, but it would be a
	 * bit of a performance penalty, I think. Hence we just use what
	 * Windows gives us, which is the same as Unix for files, at least.
	 */

	nlink = data.nNumberOfLinks;

	/*
	 * Unfortunately our stat definition's inode field (unsigned short)
	 * will throw away most of the precision we have here, which means we
	 * can't rely on inode as a unique identifier of a file. We'd really
	 * like to do something like how we handle 'st_size'.
	 */

	inode = data.nFileIndexHigh | data.nFileIndexLow;
    } else {
	/*
	 * Fall back on the less capable routines. This means no nlink or ino.
	 */

	WIN32_FILE_ATTRIBUTE_DATA data;

	if (GetFileAttributesExW(nativePath,
		GetFileExInfoStandard, &data) != TRUE) {
	    HANDLE hFind;
	    WIN32_FIND_DATAW ffd;
	    DWORD lasterror = GetLastError();

	    if (lasterror != ERROR_SHARING_VIOLATION) {
		TclWinConvertError(lasterror);
		return -1;
		}
	    hFind = FindFirstFileW(nativePath, &ffd);
	    if (hFind == INVALID_HANDLE_VALUE) {
		TclWinConvertError(GetLastError());
		return -1;
	    }
	    memcpy(&data, &ffd, sizeof(data));
	    FindClose(hFind);
	}

	attr = data.dwFileAttributes;

	statPtr->st_size = ((Tcl_WideInt)data.nFileSizeLow) |
		(((Tcl_WideInt)data.nFileSizeHigh) << 32);
	statPtr->st_atime = ToCTime(data.ftLastAccessTime);
	statPtr->st_mtime = ToCTime(data.ftLastWriteTime);
	statPtr->st_ctime = ToCTime(data.ftCreationTime);
    }

    dev = NativeDev(nativePath);
    mode = NativeStatMode(attr, checkLinks, NativeIsExec(nativePath));
    if (fileType == FILE_TYPE_CHAR) {
        mode &= ~S_IFMT;
        mode |= S_IFCHR;
    } else if (fileType == FILE_TYPE_DISK) {
        mode &= ~S_IFMT;
        mode |= S_IFBLK;
    }

    statPtr->st_dev	= (dev_t) dev;
    statPtr->st_ino	= inode;
    statPtr->st_mode	= mode;
    statPtr->st_nlink	= nlink;
    statPtr->st_uid	= 0;
    statPtr->st_gid	= 0;
    statPtr->st_rdev	= (dev_t) dev;
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * NativeDev --
 *
 *	Calculate just the 'st_dev' field of a 'stat' structure.
 *
 *----------------------------------------------------------------------
 */

static int
NativeDev(
    const WCHAR *nativePath)	/* Full path of file to stat */
{
    int dev;
    Tcl_DString ds;
    WCHAR nativeFullPath[MAX_PATH];
    WCHAR *nativePart;
    const char *fullPath;

    GetFullPathNameW(nativePath, MAX_PATH, nativeFullPath, &nativePart);
    fullPath = Tcl_WinTCharToUtf((TCHAR *)nativeFullPath, -1, &ds);

    if ((fullPath[0] == '\\') && (fullPath[1] == '\\')) {
	const char *p;
	DWORD dw;
	const WCHAR *nativeVol;
	Tcl_DString volString;

	p = strchr(fullPath + 2, '\\');
	p = strchr(p + 1, '\\');
	if (p == NULL) {
	    /*
	     * Add terminating backslash to fullpath or GetVolumeInformationW()
	     * won't work.
	     */

	    fullPath = TclDStringAppendLiteral(&ds, "\\");
	    p = fullPath + Tcl_DStringLength(&ds);
	} else {
	    p++;
	}
	nativeVol = (WCHAR *)Tcl_WinUtfToTChar(fullPath, p - fullPath, &volString);
	dw = (DWORD) -1;
	GetVolumeInformationW(nativeVol, NULL, 0, &dw, NULL, NULL, NULL, 0);

	/*
	 * GetFullPathNameW() turns special devices like "NUL" into "\\.\NUL",
	 * but GetVolumeInformationW() returns failure for "\\.\NUL". This will
	 * cause "NUL" to get a drive number of -1, which makes about as much
	 * sense as anything since the special devices don't live on any
	 * drive.
	 */

	dev = dw;
	Tcl_DStringFree(&volString);
    } else if ((fullPath[0] != '\0') && (fullPath[1] == ':')) {
	dev = Tcl_UniCharToLower(fullPath[0]) - 'a';
    } else {
	dev = -1;
    }
    Tcl_DStringFree(&ds);

    return dev;
}

/*
 *----------------------------------------------------------------------
 *
 * NativeStatMode --
 *
 *	Calculate just the 'st_mode' field of a 'stat' structure.
 *
 *	In many places we don't need the full stat structure, and it's much
 *	faster just to calculate these pieces, if that's all we need.
 *
 *----------------------------------------------------------------------
 */

static unsigned short
NativeStatMode(
    DWORD attr,
    int checkLinks,
    int isExec)
{
    int mode;

    if (checkLinks && (attr & FILE_ATTRIBUTE_REPARSE_POINT)) {
	/*
	 * It is a link.
	 */

	mode = S_IFLNK;
    } else {
	mode = (attr & FILE_ATTRIBUTE_DIRECTORY) ? S_IFDIR|S_IEXEC : S_IFREG;
    }
    mode |= (attr & FILE_ATTRIBUTE_READONLY) ? S_IREAD : S_IREAD|S_IWRITE;
    if (isExec) {
	mode |= S_IEXEC;
    }

    /*
     * Propagate the S_IREAD, S_IWRITE, S_IEXEC bits to the group and other
     * positions.
     */

    mode |= (mode & (S_IREAD|S_IWRITE|S_IEXEC)) >> 3;
    mode |= (mode & (S_IREAD|S_IWRITE|S_IEXEC)) >> 6;
    return (unsigned short) mode;
}

/*
 *------------------------------------------------------------------------
 *
 * ToCTime --
 *
 *	Converts a Windows FILETIME to a time_t in UTC.
 *
 * Results:
 *	Returns the count of seconds from the Posix epoch.
 *
 *------------------------------------------------------------------------
 */

static time_t
ToCTime(
    FILETIME fileTime)		/* UTC time */
{
    LARGE_INTEGER convertedTime;

    convertedTime.LowPart = fileTime.dwLowDateTime;
    convertedTime.HighPart = (LONG) fileTime.dwHighDateTime;

    return (time_t) ((convertedTime.QuadPart -
	    (Tcl_WideInt)POSIX_EPOCH_AS_FILETIME) / (Tcl_WideInt)10000000);
}

/*
 *------------------------------------------------------------------------
 *
 * FromCTime --
 *
 *	Converts a time_t to a Windows FILETIME
 *
 * Results:
 *	Returns the count of 100-ns ticks seconds from the Windows epoch.
 *
 *------------------------------------------------------------------------
 */

static void
FromCTime(
    time_t posixTime,
    FILETIME *fileTime)		/* UTC Time */
{
    LARGE_INTEGER convertedTime;

    convertedTime.QuadPart = ((LONGLONG) posixTime) * 10000000
	    + POSIX_EPOCH_AS_FILETIME;
    fileTime->dwLowDateTime = convertedTime.LowPart;
    fileTime->dwHighDateTime = convertedTime.HighPart;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclpGetNativeCwd --
 *
 *	This function replaces the library version of getcwd().
 *
 * Results:
 *	The input and output are filesystem paths in native form. The result
 *	is either the given clientData, if the working directory hasn't
 *	changed, or a new clientData (owned by our caller), giving the new
 *	native path, or NULL if the current directory could not be determined.
 *	If NULL is returned, the caller can examine the standard Posix error
 *	codes to determine the cause of the problem.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

ClientData
TclpGetNativeCwd(
    ClientData clientData)
{
    WCHAR buffer[MAX_PATH];

    if (GetCurrentDirectoryW(MAX_PATH, buffer) == 0) {
	TclWinConvertError(GetLastError());
	return NULL;
    }

    if (clientData != NULL) {
	if (wcscmp((const WCHAR *) clientData, buffer) == 0) {
	    return clientData;
	}
    }

    return TclNativeDupInternalRep(buffer);
}

int
TclpObjAccess(
    Tcl_Obj *pathPtr,
    int mode)
{
    return NativeAccess((const WCHAR *)Tcl_FSGetNativePath(pathPtr), mode);
}

int
TclpObjLstat(
    Tcl_Obj *pathPtr,
    Tcl_StatBuf *statPtr)
{
    /*
     * Ensure correct file sizes by forcing the OS to write any pending data
     * to disk. This is done only for channels which are dirty, i.e. have been
     * written to since the last flush here.
     */

    TclWinFlushDirtyChannels();

    return NativeStat((const WCHAR *)Tcl_FSGetNativePath(pathPtr), statPtr, 1);
}

#ifdef S_IFLNK
Tcl_Obj *
TclpObjLink(
    Tcl_Obj *pathPtr,
    Tcl_Obj *toPtr,
    int linkAction)
{
    if (toPtr != NULL) {
	int res;
	const WCHAR *LinkTarget;
	const WCHAR *LinkSource = (const WCHAR *)Tcl_FSGetNativePath(pathPtr);
	Tcl_Obj *normalizedToPtr = Tcl_FSGetNormalizedPath(NULL, toPtr);

	if (normalizedToPtr == NULL) {
	    return NULL;
	}

	LinkTarget = (const WCHAR *)Tcl_FSGetNativePath(normalizedToPtr);

	if (LinkSource == NULL || LinkTarget == NULL) {
	    return NULL;
	}
	res = WinLink(LinkSource, LinkTarget, linkAction);
	if (res == 0) {
	    return toPtr;
	} else {
	    return NULL;
	}
    } else {
	const WCHAR *LinkSource = (const WCHAR *)Tcl_FSGetNativePath(pathPtr);

	if (LinkSource == NULL) {
	    return NULL;
	}
	return WinReadLink(LinkSource);
    }
}
#endif /* S_IFLNK */

/*
 *---------------------------------------------------------------------------
 *
 * TclpFilesystemPathType --
 *
 *	This function is part of the native filesystem support, and returns
 *	the path type of the given path. Returns NTFS or FAT or whatever is
 *	returned by the 'volume information' proc.
 *
 * Results:
 *	NULL at present.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
TclpFilesystemPathType(
    Tcl_Obj *pathPtr)
{
#define VOL_BUF_SIZE 32
    int found;
    WCHAR volType[VOL_BUF_SIZE];
    char *firstSeparator;
    const char *path;
    Tcl_Obj *normPath = Tcl_FSGetNormalizedPath(NULL, pathPtr);

    if (normPath == NULL) {
	return NULL;
    }
    path = Tcl_GetString(normPath);
    if (path == NULL) {
	return NULL;
    }

    firstSeparator = strchr(path, '/');
    if (firstSeparator == NULL) {
	found = GetVolumeInformationW((const WCHAR *)Tcl_FSGetNativePath(pathPtr),
		NULL, 0, NULL, NULL, NULL, volType, VOL_BUF_SIZE);
    } else {
	Tcl_Obj *driveName = Tcl_NewStringObj(path, firstSeparator - path+1);

	Tcl_IncrRefCount(driveName);
	found = GetVolumeInformationW((const WCHAR *)Tcl_FSGetNativePath(driveName),
		NULL, 0, NULL, NULL, NULL, volType, VOL_BUF_SIZE);
	Tcl_DecrRefCount(driveName);
    }

    if (found == 0) {
	return NULL;
    } else {
	Tcl_DString ds;

	Tcl_WinTCharToUtf((TCHAR *)volType, -1, &ds);
	return TclDStringToObj(&ds);
    }
#undef VOL_BUF_SIZE
}

/*
 * This define can be turned on to experiment with a different way of
 * normalizing paths (using a different Windows API). Unfortunately the new
 * path seems to take almost exactly the same amount of time as the old path!
 * The primary time taken by normalization is in
 * GetFileAttributesEx/FindFirstFile or GetFileAttributesEx/GetLongPathName.
 * Conversion to/from native is not a significant factor at all.
 *
 * Also, since we have to check for symbolic links (reparse points) then we
 * have to call GetFileAttributes on each path segment anyway, so there's no
 * benefit to doing anything clever there.
 */

/* #define TclNORM_LONG_PATH */

/*
 *---------------------------------------------------------------------------
 *
 * TclpObjNormalizePath --
 *
 *	This function scans through a path specification and replaces it, in
 *	place, with a normalized version. This means using the 'longname', and
 *	expanding any symbolic links contained within the path.
 *
 * Results:
 *	The new 'nextCheckpoint' value, giving as far as we could understand
 *	in the path.
 *
 * Side effects:
 *	The pathPtr string, which must contain a valid path, is possibly
 *	modified in place.
 *
 *---------------------------------------------------------------------------
 */

int
TclpObjNormalizePath(
    Tcl_Interp *interp, /* not used */
    Tcl_Obj *pathPtr,	        /* An unshared object containing the path to
				 * normalize */
    int nextCheckpoint)	        /* offset to start at in pathPtr */
{
    char *lastValidPathEnd = NULL;
    Tcl_DString dsNorm;		/* This will hold the normalized string. */
    char *path, *currentPathEndPosition;
    Tcl_Obj *temp = NULL;
    int isDrive = 1;
    Tcl_DString ds;		/* Some workspace. */
    (void)interp;

    Tcl_DStringInit(&dsNorm);
    path = Tcl_GetString(pathPtr);

    currentPathEndPosition = path + nextCheckpoint;
    if (*currentPathEndPosition == '/') {
	currentPathEndPosition++;
    }
    while (1) {
	char cur = *currentPathEndPosition;

	if ((cur=='/' || cur==0) && (path != currentPathEndPosition)) {
	    /*
	     * Reached directory separator, or end of string.
	     */

	    WIN32_FILE_ATTRIBUTE_DATA data;
	    const WCHAR *nativePath = (WCHAR *)Tcl_WinUtfToTChar(path,
		    currentPathEndPosition - path, &ds);

	    if (GetFileAttributesExW(nativePath,
		    GetFileExInfoStandard, &data) != TRUE) {
		/*
		 * File doesn't exist.
		 */

		if (isDrive) {
		    int len = WinIsReserved(path);

		    if (len > 0) {
			/*
			 * Actually it does exist - COM1, etc.
			 */

			int i;

			for (i=0 ; i<len ; i++) {
			    WCHAR wc = ((WCHAR *)nativePath)[i];

			    if (wc >= 'a') {
				wc -= ('a' - 'A');
				((WCHAR *) nativePath)[i] = wc;
			    }
			}
			Tcl_DStringAppend(&dsNorm,
				(const char *)nativePath,
				(int)(sizeof(WCHAR) * len));
			lastValidPathEnd = currentPathEndPosition;
		    } else if (nextCheckpoint == 0) {
			/*
			 * Path starts with a drive designation that's not
			 * actually on the system. We still must normalize up
			 * past the first separator. [Bug 3603434]
			 */

			currentPathEndPosition++;
		    }
		}
		Tcl_DStringFree(&ds);
		break;
	    }

	    /*
	     * File 'nativePath' does exist if we get here. We now want to
	     * check if it is a symlink and otherwise continue with the
	     * rest of the path.
	     */

	    /*
	     * Check for symlinks, except at last component of path (we don't
	     * follow final symlinks). Also a drive (C:/) for example, may
	     * sometimes have the reparse flag set for some reason I don't
	     * understand. We therefore don't perform this check for drives.
	     */

	    if (cur != 0 && !isDrive &&
		    data.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT){
		Tcl_Obj *to = WinReadLinkDirectory(nativePath);

		if (to != NULL) {
		    /*
		     * Read the reparse point ok. Now, reparse points need not
		     * be normalized, otherwise we could use:
		     *
		     * Tcl_GetStringFromObj(to, &pathLen);
		     * nextCheckpoint = pathLen;
		     *
		     * So, instead we have to start from the beginning.
		     */

		    nextCheckpoint = 0;
		    Tcl_AppendToObj(to, currentPathEndPosition, -1);

		    /*
		     * Convert link to forward slashes.
		     */

		    for (path = Tcl_GetString(to); *path != 0; path++) {
			if (*path == '\\') {
			    *path = '/';
			}
		    }
		    path = Tcl_GetString(to);
		    currentPathEndPosition = path + nextCheckpoint;
		    if (temp != NULL) {
			Tcl_DecrRefCount(temp);
		    }
		    temp = to;

		    /*
		     * Reset variables so we can restart normalization.
		     */

		    isDrive = 1;
		    Tcl_DStringFree(&dsNorm);
		    Tcl_DStringFree(&ds);
		    continue;
		}
	    }

#ifndef TclNORM_LONG_PATH
	    /*
	     * Now we convert the tail of the current path to its 'long form',
	     * and append it to 'dsNorm' which holds the current normalized
	     * path
	     */

	    if (isDrive) {
		WCHAR drive = ((WCHAR *) nativePath)[0];

		if (drive >= 'a') {
		    drive -= ('a' - 'A');
		    ((WCHAR *) nativePath)[0] = drive;
		}
		Tcl_DStringAppend(&dsNorm, (const char *)nativePath,
			Tcl_DStringLength(&ds));
	    } else {
		char *checkDots = NULL;

		if (lastValidPathEnd[1] == '.') {
		    checkDots = lastValidPathEnd + 1;
		    while (checkDots < currentPathEndPosition) {
			if (*checkDots != '.') {
			    checkDots = NULL;
			    break;
			}
			checkDots++;
		    }
		}
		if (checkDots != NULL) {
		    int dotLen = currentPathEndPosition-lastValidPathEnd;

		    /*
		     * Path is just dots. We shouldn't really ever see a path
		     * like that. However, to be nice we at least don't mangle
		     * the path - we just add the dots as a path segment and
		     * continue.
		     */

		    Tcl_DStringAppend(&dsNorm, ((const char *)nativePath)
			    + Tcl_DStringLength(&ds)
			    - (dotLen * sizeof(WCHAR)),
			    dotLen * sizeof(WCHAR));
		} else {
		    /*
		     * Normal path.
		     */

		    WIN32_FIND_DATAW fData;
		    HANDLE handle;

		    handle = FindFirstFileW((WCHAR *) nativePath, &fData);
		    if (handle == INVALID_HANDLE_VALUE) {
			/*
			 * This is usually the '/' in 'c:/' at end of string.
			 */

			Tcl_DStringAppend(&dsNorm, (const char *) L"/",
				sizeof(WCHAR));
		    } else {
			WCHAR *nativeName;

			if (fData.cFileName[0] != '\0') {
			    nativeName = fData.cFileName;
			} else {
			    nativeName = fData.cAlternateFileName;
			}
			FindClose(handle);
			Tcl_DStringAppend(&dsNorm, (const char *) L"/",
				sizeof(WCHAR));
			Tcl_DStringAppend(&dsNorm,
				(const char *) nativeName,
				(int) (wcslen(nativeName)*sizeof(WCHAR)));
		    }
		}
	    }
#endif /* !TclNORM_LONG_PATH */
	    Tcl_DStringFree(&ds);
	    lastValidPathEnd = currentPathEndPosition;
	    if (cur == 0) {
		break;
	    }

	    /*
	     * If we get here, we've got past one directory delimiter, so we
	     * know it is no longer a drive.
	     */

	    isDrive = 0;
	}
	currentPathEndPosition++;

#ifdef TclNORM_LONG_PATH
	/*
	 * Convert the entire known path to long form.
	 */

	if (1) {
	    WCHAR wpath[MAX_PATH];
	    const WCHAR *nativePath =
		    Tcl_WinUtfToTChar(path, lastValidPathEnd - path, &ds);
	    DWORD wpathlen = GetLongPathNameProc(nativePath,
		    (WCHAR *) wpath, MAX_PATH);

	    /*
	     * We have to make the drive letter uppercase.
	     */

	    if (wpath[0] >= 'a') {
		wpath[0] -= ('a' - 'A');
	    }
	    Tcl_DStringAppend(&dsNorm, (const char *) wpath,
		    wpathlen * sizeof(WCHAR));
	    Tcl_DStringFree(&ds);
	}
#endif /* TclNORM_LONG_PATH */
    }

    /*
     * Common code path for all Windows platforms.
     */

    nextCheckpoint = currentPathEndPosition - path;
    if (lastValidPathEnd != NULL) {
	/*
	 * Concatenate the normalized string in dsNorm with the tail of the
	 * path which we didn't recognise. The string in dsNorm is in the
	 * native encoding, so we have to convert it to Utf.
	 */

	Tcl_WinTCharToUtf((TCHAR *) Tcl_DStringValue(&dsNorm),
		Tcl_DStringLength(&dsNorm), &ds);
	nextCheckpoint = Tcl_DStringLength(&ds);
	if (*lastValidPathEnd != 0) {
	    /*
	     * Not the end of the string.
	     */

	    int len;
	    Tcl_Obj *tmpPathPtr;

	    tmpPathPtr = Tcl_NewStringObj(Tcl_DStringValue(&ds),
		    nextCheckpoint);
	    Tcl_AppendToObj(tmpPathPtr, lastValidPathEnd, -1);
	    path = Tcl_GetStringFromObj(tmpPathPtr, &len);
	    Tcl_SetStringObj(pathPtr, path, len);
	    Tcl_DecrRefCount(tmpPathPtr);
	} else {
	    /*
	     * End of string was reached above.
	     */

	    Tcl_SetStringObj(pathPtr, Tcl_DStringValue(&ds), nextCheckpoint);
	}
	Tcl_DStringFree(&ds);
    }
    Tcl_DStringFree(&dsNorm);

    /*
     * This must be done after we are totally finished with 'path' as we are
     * sharing the same underlying string.
     */

    if (temp != NULL) {
	Tcl_DecrRefCount(temp);
    }

    return nextCheckpoint;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclWinVolumeRelativeNormalize --
 *
 *	Only Windows has volume-relative paths. These paths are rather rare,
 *	but it is nice if Tcl can handle them. It is much better if we can
 *	handle them here, rather than in the native fs code, because we really
 *	need to have a real absolute path just below.
 *
 *	We do not let this block compile on non-Windows platforms because the
 *	test suite's manual forcing of tclPlatform can otherwise cause this
 *	code path to be executed, causing various errors because
 *	volume-relative paths really do not exist.
 *
 * Results:
 *	A valid normalized path.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
TclWinVolumeRelativeNormalize(
    Tcl_Interp *interp,
    const char *path,
    Tcl_Obj **useThisCwdPtr)
{
    Tcl_Obj *absolutePath, *useThisCwd;

    useThisCwd = Tcl_FSGetCwd(interp);
    if (useThisCwd == NULL) {
	return NULL;
    }

    if (path[0] == '/') {
	/*
	 * Path of form /foo/bar which is a path in the root directory of the
	 * current volume.
	 */

	const char *drive = Tcl_GetString(useThisCwd);

	absolutePath = Tcl_NewStringObj(drive,2);
	Tcl_AppendToObj(absolutePath, path, -1);
	Tcl_IncrRefCount(absolutePath);

	/*
	 * We have a refCount on the cwd.
	 */
    } else {
	/*
	 * Path of form C:foo/bar, but this only makes sense if the cwd is
	 * also on drive C.
	 */

	int cwdLen;
	const char *drive =
		Tcl_GetStringFromObj(useThisCwd, &cwdLen);
	char drive_cur = path[0];

	if (drive_cur >= 'a') {
	    drive_cur -= ('a' - 'A');
	}
	if (drive[0] == drive_cur) {
	    absolutePath = Tcl_DuplicateObj(useThisCwd);

	    /*
	     * We have a refCount on the cwd, which we will release later.
	     */

	    if (drive[cwdLen-1] != '/' && (path[2] != '\0')) {
		/*
		 * Only add a trailing '/' if needed, which is if there isn't
		 * one already, and if we are going to be adding some more
		 * characters.
		 */

		Tcl_AppendToObj(absolutePath, "/", 1);
	    }
	} else {
	    Tcl_DecrRefCount(useThisCwd);
	    useThisCwd = NULL;

	    /*
	     * The path is not in the current drive, but is volume-relative.
	     * The way Tcl 8.3 handles this is that it treats such a path as
	     * relative to the root of the drive. We therefore behave the same
	     * here. This behaviour is, however, different to that of the
	     * windows command-line. If we want to fix this at some point in
	     * the future (at the expense of a behaviour change to Tcl), we
	     * could use the '_dgetdcwd' Win32 API to get the drive's cwd.
	     */

	    absolutePath = Tcl_NewStringObj(path, 2);
	    Tcl_AppendToObj(absolutePath, "/", 1);
	}
	Tcl_IncrRefCount(absolutePath);
	Tcl_AppendToObj(absolutePath, path+2, -1);
    }
    *useThisCwdPtr = useThisCwd;
    return absolutePath;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclpNativeToNormalized --
 *
 *	Convert native format to a normalized path object, with refCount of
 *	zero.
 *
 *	Currently assumes all native paths are actually normalized already, so
 *	if the path given is not normalized this will actually just convert to
 *	a valid string path, but not necessarily a normalized one.
 *
 * Results:
 *	A valid normalized path.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
TclpNativeToNormalized(
    ClientData clientData)
{
    Tcl_DString ds;
    Tcl_Obj *objPtr;
    int len;
    char *copy, *p;

    Tcl_WinTCharToUtf((TCHAR *) clientData, -1, &ds);
    copy = Tcl_DStringValue(&ds);
    len = Tcl_DStringLength(&ds);

    /*
     * Certain native path representations on Windows have this special prefix
     * to indicate that they are to be treated specially. For example
     * extremely long paths, or symlinks.
     */

    if (*copy == '\\') {
	if (0 == strncmp(copy,"\\??\\",4)) {
	    copy += 4;
	    len -= 4;
	} else if (0 == strncmp(copy,"\\\\?\\",4)) {
	    copy += 4;
	    len -= 4;
	}
    }

    /*
     * Ensure we are using forward slashes only.
     */

    for (p = copy; *p != '\0'; p++) {
	if (*p == '\\') {
	    *p = '/';
	}
    }

    objPtr = Tcl_NewStringObj(copy,len);
    Tcl_DStringFree(&ds);

    return objPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclNativeCreateNativeRep --
 *
 *	Create a native representation for the given path.
 *
 * Results:
 *	The nativePath representation.
 *
 * Side effects:
 *	Memory will be allocated. The path might be normalized.
 *
 *---------------------------------------------------------------------------
 */

ClientData
TclNativeCreateNativeRep(
    Tcl_Obj *pathPtr)
{
    WCHAR *nativePathPtr = NULL;
    const char *str;
    Tcl_Obj *validPathPtr;
    int len;
    WCHAR *wp;
    Tcl_DString ds;
    Tcl_Encoding utf8;

    if (TclFSCwdIsNative()) {
	/*
	 * The cwd is native, which means we can use the translated path
	 * without worrying about normalization (this will also usually be
	 * shorter so the utf-to-external conversion will be somewhat faster).
	 */

	validPathPtr = Tcl_FSGetTranslatedPath(NULL, pathPtr);
	if (validPathPtr == NULL) {
	    return NULL;
	}

	/*
	 * refCount of validPathPtr was already incremented in
	 * Tcl_FSGetTranslatedPath
	 */
    } else {
	/*
	 * Make sure the normalized path is set.
	 */

	validPathPtr = Tcl_FSGetNormalizedPath(NULL, pathPtr);
	if (validPathPtr == NULL) {
	    return NULL;
	}

	/*
	 * validPathPtr returned from Tcl_FSGetNormalizedPath is owned by Tcl,
	 * so incr refCount here
	 */

	Tcl_IncrRefCount(validPathPtr);
    }

    utf8 = Tcl_GetEncoding(NULL, "utf-8");
    str = Tcl_GetStringFromObj(validPathPtr, &len);
    str = Tcl_UtfToExternalDString(utf8, str, len, &ds);
    len = Tcl_DStringLength(&ds);
    Tcl_FreeEncoding(utf8);

    if (strlen(str) != (size_t)len) {
	/*
	 * String contains NUL-bytes. This is invalid.
	 */

	goto done;
    }

    /*
     * For a reserved device, strip a possible postfix ':'
     */

    len = WinIsReserved(str);
    if (len == 0) {
	/*
	 * Let MultiByteToWideChar check for other invalid sequences, like
	 * 0xC0 0x80 (== overlong NUL). See bug [3118489]: NUL in filenames
	 */

	len = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str, -1, 0, 0);
	if (len==0) {
	    goto done;
	}
    }

    /*
     * Overallocate 6 chars, making some room for extended paths
     */

    wp = nativePathPtr = (WCHAR *)ckalloc((len + 6) * sizeof(WCHAR));
    if (nativePathPtr==0) {
      goto done;
    }
    MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str, -1, nativePathPtr,
	    len + 2);
    nativePathPtr[len] = 0;

    /*
     * If path starts with "//?/" or "\\?\" (extended path), translate any
     * slashes to backslashes but leave the '?' intact
     */

    if ((str[0] == '\\' || str[0] == '/') && (str[1] == '\\' || str[1] == '/')
	    && str[2] == '?' && (str[3] == '\\' || str[3] == '/')) {
	wp[0] = wp[1] = wp[3] = '\\';
	str += 4;
	wp += 4;
    }

    /*
     * If there is no "\\?\" prefix but there is a drive or UNC path prefix
     * and the path is larger than MAX_PATH chars, no Win32 API function can
     * handle that unless it is prefixed with the extended path prefix. See:
     * <https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#maxpath>
     */

    if (((str[0] >= 'A' && str[0] <= 'Z') || (str[0] >= 'a' && str[0] <= 'z'))
	    && str[1] == ':') {
	if (wp == nativePathPtr && len > MAX_PATH
		&& (str[2] == '\\' || str[2] == '/')) {
	    memmove(wp + 4, wp, len * sizeof(WCHAR));
	    memcpy(wp, L"\\\\?\\", 4 * sizeof(WCHAR));
	    wp += 4;
	}

	/*
	 * If (remainder of) path starts with "<drive>:", leave the ':'
	 * intact.
	 */

	wp += 2;
    } else if (wp == nativePathPtr && len > MAX_PATH
	    && (str[0] == '\\' || str[0] == '/')
	    && (str[1] == '\\' || str[1] == '/') && str[2] != '?') {
	memmove(wp + 6, wp, len * sizeof(WCHAR));
	memcpy(wp, L"\\\\?\\UNC", 7 * sizeof(WCHAR));
	wp += 7;
    }

    /*
     * In the remainder of the path, translate invalid characters to
     * characters in the Unicode private use area.
     */

    while (*wp != '\0') {
	if ((*wp < ' ') || wcschr(L"\"*<>?|", *wp)) {
	    *wp |= 0xF000;
	} else if (*wp == '/') {
	    *wp = '\\';
	}
	++wp;
    }

  done:
    Tcl_DStringFree(&ds);
    TclDecrRefCount(validPathPtr);
    return nativePathPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclNativeDupInternalRep --
 *
 *	Duplicate the native representation.
 *
 * Results:
 *	The copied native representation, or NULL if it is not possible to
 *	copy the representation.
 *
 * Side effects:
 *	Memory allocation for the copy.
 *
 *---------------------------------------------------------------------------
 */

ClientData
TclNativeDupInternalRep(
    ClientData clientData)
{
    char *copy;
    size_t len;

    if (clientData == NULL) {
	return NULL;
    }

    len = sizeof(WCHAR) * (wcslen((const WCHAR *) clientData) + 1);

    copy = (char *)ckalloc(len);
    memcpy(copy, clientData, len);
    return copy;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclpUtime --
 *
 *	Set the modification date for a file.
 *
 * Results:
 *	0 on success, -1 on error.
 *
 * Side effects:
 *	Sets errno to a representation of any Windows problem that's observed
 *	in the process.
 *
 *---------------------------------------------------------------------------
 */

int
TclpUtime(
    Tcl_Obj *pathPtr,		/* File to modify */
    struct utimbuf *tval)	/* New modification date structure */
{
    int res = 0;
    HANDLE fileHandle;
    const WCHAR *native;
    DWORD attr = 0;
    DWORD flags = FILE_ATTRIBUTE_NORMAL;
    FILETIME lastAccessTime, lastModTime;

    FromCTime(tval->actime, &lastAccessTime);
    FromCTime(tval->modtime, &lastModTime);

    native = (const WCHAR *)Tcl_FSGetNativePath(pathPtr);

    attr = GetFileAttributesW(native);

    if (attr != INVALID_FILE_ATTRIBUTES && attr & FILE_ATTRIBUTE_DIRECTORY) {
	flags = FILE_FLAG_BACKUP_SEMANTICS;
    }

    /*
     * We use the native APIs (not 'utime') because there are some daylight
     * savings complications that utime gets wrong.
     */

    fileHandle = CreateFileW(native, FILE_WRITE_ATTRIBUTES, 0, NULL,
	    OPEN_EXISTING, flags, NULL);

    if (fileHandle == INVALID_HANDLE_VALUE ||
	    !SetFileTime(fileHandle, NULL, &lastAccessTime, &lastModTime)) {
	TclWinConvertError(GetLastError());
	res = -1;
    }
    if (fileHandle != INVALID_HANDLE_VALUE) {
	CloseHandle(fileHandle);
    }
    return res;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclWinFileOwned --
 *
 *	Returns 1 if the specified file exists and is owned by the current
 *      user and 0 otherwise. Like the Unix case, the check is made using
 *      the real process SID, not the effective (impersonation) one.
 *
 *---------------------------------------------------------------------------
 */

int
TclWinFileOwned(
    Tcl_Obj *pathPtr)		/* File whose ownership is to be checked */
{
    const WCHAR *native;
    PSID ownerSid = NULL;
    PSECURITY_DESCRIPTOR secd = NULL;
    HANDLE token;
    LPBYTE buf = NULL;
    DWORD bufsz;
    int owned = 0;

    native = (const WCHAR *)Tcl_FSGetNativePath(pathPtr);

    if (GetNamedSecurityInfoW((LPWSTR) native, SE_FILE_OBJECT,
	    OWNER_SECURITY_INFORMATION, &ownerSid, NULL, NULL, NULL,
	    &secd) != ERROR_SUCCESS) {
        /*
	 * Either not a file, or we do not have access to it in which case we
	 * are in all likelihood not the owner.
	 */

        return 0;
    }

    /*
     * Getting the current process SID is a multi-step process.  We make the
     * assumption that if a call fails, this process is so underprivileged it
     * could not possibly own anything. Normally a process can *always* look
     * up its own token.
     */

    if (OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &token)) {
        /*
	 * Find out how big the buffer needs to be.
	 */

        bufsz = 0;
        GetTokenInformation(token, TokenUser, NULL, 0, &bufsz);
        if (bufsz) {
            buf = (LPBYTE)ckalloc(bufsz);
            if (GetTokenInformation(token, TokenUser, buf, bufsz, &bufsz)) {
                owned = EqualSid(ownerSid, ((PTOKEN_USER) buf)->User.Sid);
            }
        }
        CloseHandle(token);
    }

    /*
     * Free allocations and be done.
     */

    if (secd) {
        LocalFree(secd);            /* Also frees ownerSid */
    }
    if (buf) {
        ckfree(buf);
    }

    return (owned != 0);        /* Convert non-0 to 1 */
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */
