path: root/win/tclWinFile.c

/*
 * 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.
 *
 * RCS: @(#) $Id: tclWinFile.c,v 1.117 2010/12/13 13:57:58 nijtmans Exp $
 */

#include "tclWinInt.h"
#include "tclFileSystem.h"
#include <winioctl.h>
#include <sys/stat.h>
#include <shlobj.h>
#include <lm.h>		/* For TclpGetUserHome(). */

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

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

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

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

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

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

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

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

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

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

    /*
     * Check the target.
     */

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

	TclWinConvertError(GetLastError());
	return -1;

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

	if (CreateHardLink == NULL) {
	    Tcl_SetErrno(ENOTDIR);
	    return -1;
	}

	if (linkAction & TCL_CREATE_HARD_LINK) {
	    if (!CreateHardLink(linkSourcePath,
		    linkTargetPath, NULL)) {
		TclWinConvertError(GetLastError());
		return -1;
	    }
	    return 0;

	} else if (linkAction & TCL_CREATE_SYMBOLIC_LINK) {
	    /*
	     * Can't symlink files.
	     */

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

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

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

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

	TclWinConvertError(GetLastError());
	return NULL;
    }

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

    attr = GetFileAttributes(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;
    } else {
	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 TCHAR *linkDirPath,
    const TCHAR *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 == L'/') {
	    *loop = L'\\';
	}
    }
    if ((nativeTarget[len-1] == L'\\') && (nativeTarget[len-2] != L':')) {
	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 TCHAR *linkOrigPath,	/* Existing junction - reparse point */
    const TCHAR *linkCopyPath)	/* Will become a duplicate junction */
{
    DUMMY_REPARSE_BUFFER dummy;
    REPARSE_DATA_BUFFER *reparseBuffer = (REPARSE_DATA_BUFFER *) &dummy;

    if (NativeReadReparse(linkOrigPath, reparseBuffer)) {
	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 TCHAR *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 = CreateFile(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) {
		RemoveDirectory(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.
 *
 *--------------------------------------------------------------------
 */

static Tcl_Obj *
WinReadLinkDirectory(
    const TCHAR *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 = GetFileAttributes(linkDirPath);
    if (!(attr & FILE_ATTRIBUTE_REPARSE_POINT)) {
	goto invalidError;
    }
    if (NativeReadReparse(linkDirPath, reparseBuffer)) {
	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;
#ifdef UNICODE
	if (reparseBuffer->MountPointReparseBuffer.PathBuffer[0] == L'\\') {
	    /*
	     * 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]=L'\\';

		/*
		 * 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;
	    }
	}
#endif /* UNICODE */

	Tcl_WinTCharToUtf((const TCHAR *)
		reparseBuffer->MountPointReparseBuffer.PathBuffer,
		(int) 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;
}

/*
 *--------------------------------------------------------------------
 *
 * 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 TCHAR *linkDirPath,	/* The junction to read */
    REPARSE_DATA_BUFFER *buffer)/* Pointer to buffer. Cannot be NULL */
{
    HANDLE hFile;
    DWORD returnedLength;

    hFile = CreateFile(linkDirPath, GENERIC_READ, 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;
    }

    /*
     * 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 TCHAR *linkDirPath,
    REPARSE_DATA_BUFFER *buffer)
{
    HANDLE hFile;
    DWORD returnedLength;

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

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

	TclWinConvertError(GetLastError());
	return -1;
    }
    hFile = CreateFile(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);
	RemoveDirectory(linkDirPath);
	return -1;
    }
    CloseHandle(hFile);

    /*
     * We succeeded.
     */

    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * WishPanic --
 *
 *	Display a message.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
PanicMessageBox(
    const char *format, ...)
{
#define TCL_MAX_WARN_LEN 1024
    va_list argList;
    char buf[TCL_MAX_WARN_LEN * TCL_UTF_MAX];
    WCHAR msgString[TCL_MAX_WARN_LEN];

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

    msgString[TCL_MAX_WARN_LEN-1] = L'\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] != L'\0') {
		memcpy(msgString + (TCL_MAX_WARN_LEN - 5), L" ...", 5 * sizeof(WCHAR));
	}
    MessageBeep(MB_ICONEXCLAMATION);
    MessageBoxW(NULL, msgString, L"Fatal Error",
	    MB_ICONSTOP | MB_OK | MB_TASKMODAL | MB_SETFOREGROUND);
    /* We don't need to abort here, because our caller already does. */
}

/*
 *---------------------------------------------------------------------------
 *
 * 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 * TCL_UTF_MAX];

    /*
     * 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(PanicMessageBox);
    }

#ifdef UNICODE
    GetModuleFileNameW(NULL, wName, MAX_PATH);
#else
    GetModuleFileNameA(NULL, name, sizeof(name));

    /*
     * Convert to WCHAR to get out of ANSI codepage
     */

    MultiByteToWideChar(CP_ACP, 0, name, -1, wName, MAX_PATH);
#endif
    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 TCHAR *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;
	    const char *str = Tcl_GetStringFromObj(norm,&len);

	    native = Tcl_FSGetNativePath(pathPtr);

	    if (GetFileAttributesEx == NULL) {
		attr = GetFileAttributes(native);
		if (attr == INVALID_FILE_ATTRIBUTES) {
		    return TCL_OK;
		}
	    } else {
		WIN32_FILE_ATTRIBUTE_DATA data;

		if (GetFileAttributesEx(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_DATA 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 = Tcl_FSGetNativePath(pathPtr);
	if (native == NULL) {
	    return TCL_OK;
	}
	attr = GetFileAttributes(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 != ':')) {
	    Tcl_DStringAppend(&dsOrig, "/", 1);
	    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 = Tcl_DStringAppend(&dsOrig, "*.*", 3);
	}

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

	    handle = FindFirstFileEx(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_ResetResult(interp);
		Tcl_AppendResult(interp, "couldn't read directory \"",
			Tcl_DStringValue(&dsOrig), "\": ",
			Tcl_PosixError(interp), NULL);
	    }
	    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;
	    DWORD attr;

	    native = data.cFileName;
	    attr = data.dwFileAttributes;
	    utfname = Tcl_WinTCharToUtf(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 (FindNextFile(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) */
    int 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] <= '4') {
	    /*
	     * May have match for 'com[1-4]:?', 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] <= '3') {
	    /*
	     * May have match for 'lpt[1-3]:?'
	     */

	    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 calss 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 TCHAR *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.
	 */

	if (attr & FILE_ATTRIBUTE_HIDDEN && !isDrive) {
	    return 0;
	}
    } else {
	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
		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. */
{
    const char *result = NULL;
    USER_INFO_1 *uiPtr, **uiPtrPtr = &uiPtr;
    Tcl_DString ds;
    int nameLen = -1;
    int badDomain = 0;
    char *domain;
    WCHAR *wName, *wHomeDir, *wDomain, **wDomainPtr = &wDomain;
    WCHAR buf[MAX_PATH];

    Tcl_DStringInit(bufferPtr);
    wDomain = NULL;
    domain = strchr(name, '@');
    if (domain != NULL) {
	Tcl_DStringInit(&ds);
	wName = Tcl_UtfToUniCharDString(domain + 1, -1, &ds);
	badDomain = NetGetDCName(NULL, wName,
		(LPBYTE *) wDomainPtr);
	Tcl_DStringFree(&ds);
	nameLen = domain - name;
    }
    if (badDomain == 0) {
	Tcl_DStringInit(&ds);
	wName = Tcl_UtfToUniCharDString(name, nameLen, &ds);
	if (NetUserGetInfo(wDomain, wName, 1,
		(LPBYTE *) uiPtrPtr) == 0) {
	    wHomeDir = uiPtr->usri1_home_dir;
	    if ((wHomeDir != NULL) && (wHomeDir[0] != L'\0')) {
		Tcl_UniCharToUtfDString(wHomeDir, lstrlenW(wHomeDir),
			bufferPtr);
	    } else {
		/*
		 * User exists but has no home dir. Return
		 * "{Windows Drive}:/users/default".
		 */

		GetWindowsDirectoryW(buf, MAX_PATH);
		Tcl_UniCharToUtfDString(buf, 2, bufferPtr);
		Tcl_DStringAppend(bufferPtr, "/users/default", -1);
	    }
	    result = Tcl_DStringValue(bufferPtr);
	    NetApiBufferFree((void *) uiPtr);
	}
	Tcl_DStringFree(&ds);
    }
    if (wDomain != NULL) {
	NetApiBufferFree((void *) wDomain);
    }
    if (result == NULL) {
	/*
	 * Look in the "Password Lists" section of system.ini for the local
	 * user. There are also entries in that section that begin with a "*"
	 * character that are used by Windows for other purposes; ignore user
	 * names beginning with a "*".
	 */

	char buf[MAX_PATH];

	if (name[0] != '*') {
	    if (GetPrivateProfileStringA("Password Lists", name, "", buf,
		    MAX_PATH, "system.ini") > 0) {
		/*
		 * User exists, but there is no such thing as a home directory
		 * in system.ini. Return "{Windows drive}:/".
		 */

		GetWindowsDirectoryA(buf, MAX_PATH);
		Tcl_DStringAppend(bufferPtr, buf, 3);
		result = Tcl_DStringValue(bufferPtr);
	    }
	}
    }

    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 TCHAR *nativePath,	/* Path of file to access, native encoding. */
    int mode)			/* Permission setting. */
{
    DWORD attr;

    attr = GetFileAttributes(nativePath);

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

	WIN32_FIND_DATA ffd;
	HANDLE hFind;
	hFind = FindFirstFile(nativePath, &ffd);
	if (hFind != INVALID_HANDLE_VALUE) {
	    attr = ffd.dwFileAttributes;
	    FindClose(hFind);
	} else {
	    TclWinConvertError(GetLastError());
	    return -1;
	}
    }

#ifndef UNICODE
    if ((mode & W_OK)
	    && (attr & FILE_ATTRIBUTE_READONLY)) {
	/*
	 * We don't have the advanced 'GetFileSecurity', and our
	 * attributes say the file is not writable. If we do have
	 * 'GetFileSecurity', we'll do a more robust XP-related check
	 * below.
	 */

	Tcl_SetErrno(EACCES);
	return -1;
    }
#endif /* !UNICODE */

    if (mode & X_OK) {
	if (!(attr & FILE_ATTRIBUTE_DIRECTORY) && !NativeIsExec(nativePath)) {
	    /*
	     * It's not a directory and doesn't have the correct extension.
	     * Therefore it can't be executable
	     */

	    Tcl_SetErrno(EACCES);
	    return -1;
	}
    }

    /*
     * 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.
     *
     * If we are simply checking for file existence, then we don't need all
     * these complications (which are really quite slow: with this code 'file
     * readable' is 5-6 times slower than 'file exists').
     */

    if (mode != F_OK) {
	SECURITY_DESCRIPTOR *sdPtr = NULL;
	unsigned long size;
	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;
	GetFileSecurity(nativePath,
		OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION
		| DACL_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 GetFileSecurity() for real.
	 */

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

	    goto accessError;
	}

	/*
	 * 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 priveleges 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;
	}

	/*
	 * For directories the above checks are ok. For files, though, we must
	 * still check the 'attr' value.
	 */

	if ((mode & W_OK)
		&& !(attr & FILE_ATTRIBUTE_DIRECTORY)
		&& (attr & FILE_ATTRIBUTE_READONLY)) {
	    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 any of ".exe", ".com", or ".bat"
 *
 * Results:
 *	1 = executable, 0 = not.
 *
 *----------------------------------------------------------------------
 */

static int
NativeIsExec(
    const TCHAR *path)
{
    int len = _tcslen(path);

    if (len < 5) {
	return 0;
    }

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

    if ((_tcsicmp(path+len-3, TEXT("exe")) == 0)
	    || (_tcsicmp(path+len-3, TEXT("com")) == 0)
	    || (_tcsicmp(path+len-3, TEXT("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 TCHAR *nativePath;
#ifdef __CYGWIN__
    extern int cygwin_conv_to_posix_path(const char *, char *);
    char posixPath[MAX_PATH+1];
    const char *path;
    Tcl_DString ds;
#endif /* __CYGWIN__ */

    nativePath = Tcl_FSGetNativePath(pathPtr);

#ifdef __CYGWIN__
    /*
     * Cygwin chdir only groks POSIX path.
     */

    path = Tcl_WinTCharToUtf(nativePath, -1, &ds);
    cygwin_conv_to_posix_path(path, posixPath);
    result = (chdir(posixPath) == 0 ? 1 : 0);
    Tcl_DStringFree(&ds);
#else /* __CYGWIN__ */
    result = SetCurrentDirectory(nativePath);
#endif /* __CYGWIN__ */

    if (result == 0) {
	TclWinConvertError(GetLastError());
	return -1;
    }
    return 0;
}

#ifdef __CYGWIN__
/*
 *---------------------------------------------------------------------------
 *
 * TclpReadlink --
 *
 *	This function replaces the library version of readlink().
 *
 * Results:
 *	The result is a pointer to a string specifying the contents of the
 *	symbolic link given by 'path', or NULL if the symbolic link could not
 *	be read. Storage for the result string is allocated in bufferPtr; the
 *	caller must call Tcl_DStringFree() when the result is no longer
 *	needed.
 *
 * Side effects:
 *	See readlink() documentation.
 *
 *---------------------------------------------------------------------------
 */

char *
TclpReadlink(
    const char *path,		/* Path of file to readlink (UTF-8). */
    Tcl_DString *linkPtr)	/* Uninitialized or free DString filled with
				 * contents of link (UTF-8). */
{
    char link[MAXPATHLEN];
    int length;
    char *native;
    Tcl_DString ds;

    native = Tcl_UtfToExternalDString(NULL, path, -1, &ds);
    length = readlink(native, link, sizeof(link));	/* INTL: Native. */
    Tcl_DStringFree(&ds);

    if (length < 0) {
	return NULL;
    }

    Tcl_ExternalToUtfDString(NULL, link, length, linkPtr);
    return Tcl_DStringValue(linkPtr);
}
#endif /* __CYGWIN__ */

/*
 *----------------------------------------------------------------------
 *
 * 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. */
{
    TCHAR buffer[MAX_PATH];
    char *p;
    WCHAR *native;

    if (GetCurrentDirectory(MAX_PATH, buffer) == 0) {
	TclWinConvertError(GetLastError());
	if (interp != NULL) {
	    Tcl_AppendResult(interp, "error getting working directory name: ",
		    Tcl_PosixError(interp), NULL);
	}
	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(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 TCHAR *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;

    /*
     * 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.
     */

    fileHandle = CreateFile(nativePath, GENERIC_READ,
	    FILE_SHARE_READ | FILE_SHARE_WRITE, 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) {
	    CloseHandle(fileHandle);
	    Tcl_SetErrno(ENOENT);
	    return -1;
	}
	CloseHandle(fileHandle);

	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);

	/*
	 * 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 (GetFileAttributesEx(nativePath,
		GetFileExInfoStandard, &data) != TRUE) {

	    /*
	     * We might have just been denied access
	     */
	    
	    WIN32_FIND_DATA ffd;
	    HANDLE hFind;
	    hFind = FindFirstFile(nativePath, &ffd);
	    if (hFind != INVALID_HANDLE_VALUE) {
		memcpy(&data, &ffd, sizeof(data));
		FindClose(hFind);
	    } else {
		Tcl_SetErrno(ENOENT);
		return -1;
	    }
	}

	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));

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

    GetFullPathName(nativePath, MAX_PATH, nativeFullPath,
	    &nativePart);

    fullPath = Tcl_WinTCharToUtf(nativeFullPath, -1, &ds);

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

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

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

	/*
	 * GetFullPathName() turns special devices like "NUL" into "\\.\NUL",
	 * but GetVolumeInformation() 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 & 0x0700) >> 3;
    mode |= (mode & 0x0700) >> 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)
{
    TCHAR buffer[MAX_PATH];

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

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

    return TclNativeDupInternalRep(buffer);
}

int
TclpObjAccess(
    Tcl_Obj *pathPtr,
    int mode)
{
    return NativeAccess(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(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 TCHAR *LinkTarget;
	const TCHAR *LinkSource = Tcl_FSGetNativePath(pathPtr);
	Tcl_Obj *normalizedToPtr = Tcl_FSGetNormalizedPath(NULL, toPtr);

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

	LinkTarget = 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 TCHAR *LinkSource = Tcl_FSGetNativePath(pathPtr);

	if (LinkSource == NULL) {
	    return NULL;
	}
	return WinReadLink(LinkSource);
    }
}
#endif

/*
 *---------------------------------------------------------------------------
 *
 * 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;
    TCHAR 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 = GetVolumeInformation(
			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 = GetVolumeInformation(
			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_Obj *objPtr;

	Tcl_WinTCharToUtf(volType, -1, &ds);
	objPtr = Tcl_NewStringObj(Tcl_DStringValue(&ds),
		Tcl_DStringLength(&ds));
	Tcl_DStringFree(&ds);
	return objPtr;
    }
#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,
    Tcl_Obj *pathPtr,
    int nextCheckpoint)
{
    char *lastValidPathEnd = NULL;
    Tcl_DString dsNorm;		/* This will hold the normalized string. */
    char *path, *currentPathEndPosition;
    Tcl_Obj *temp = NULL;

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

    if (TclWinGetPlatformId() == VER_PLATFORM_WIN32_WINDOWS) {
	/*
	 * We're on Win95, 98 or ME. There are two assumptions in this block
	 * of code. First that the native (NULL) encoding is basically ascii,
	 * and second that symbolic links are not possible. Both of these
	 * assumptions appear to be true of these operating systems.
	 */

	int isDrive = 1;
	Tcl_DString ds;

	currentPathEndPosition = path + nextCheckpoint;
	if (*currentPathEndPosition == '/') {
	    currentPathEndPosition++;
	}

	while (1) {
	    char cur = *currentPathEndPosition;

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

		const char *nativePath = Tcl_UtfToExternalDString(NULL, path,
			currentPathEndPosition - path, &ds);

		/*
		 * 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 the file exists.
		 */

		if (isDrive) {
		    if (GetFileAttributesA(nativePath)
			    == INVALID_FILE_ATTRIBUTES) {
			/*
			 * 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++) {
				    if (nativePath[i] >= 'a') {
					((char *) nativePath)[i] -= ('a'-'A');
				    }
				}
				Tcl_DStringAppend(&dsNorm, nativePath, len);
				lastValidPathEnd = currentPathEndPosition;
			    }
			}
			Tcl_DStringFree(&ds);
			break;
		    }
		    if (nativePath[0] >= 'a') {
			((char *) nativePath)[0] -= ('a' - 'A');
		    }
		    Tcl_DStringAppend(&dsNorm, 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),
				dotLen);
		    } else {
			/*
			 * Normal path.
			 */

			WIN32_FIND_DATAA fData;
			HANDLE handle;

			handle = FindFirstFileA(nativePath, &fData);
			if (handle == INVALID_HANDLE_VALUE) {
			    if (GetFileAttributesA(nativePath)
				    == INVALID_FILE_ATTRIBUTES) {
				/*
				 * File doesn't exist.
				 */

				Tcl_DStringFree(&ds);
				break;
			    }

			    /*
			     * This is usually the '/' in 'c:/' at end of
			     * string.
			     */

			    Tcl_DStringAppend(&dsNorm,"/", 1);
			} else {
			    char *nativeName;

			    if (fData.cFileName[0] != '\0') {
				nativeName = fData.cFileName;
			    } else {
				nativeName = fData.cAlternateFileName;
			    }
			    FindClose(handle);
			    Tcl_DStringAppend(&dsNorm,"/", 1);
			    Tcl_DStringAppend(&dsNorm,nativeName,-1);
			}
		    }
		}
		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++;
	}
    } else {
	/*
	 * We're on WinNT (or 2000 or XP; something with an NT core).
	 */

	int isDrive = 1;
	Tcl_DString ds;

	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 TCHAR *nativePath = Tcl_WinUtfToTChar(path,
			currentPathEndPosition - path, &ds);

		if (GetFileAttributesEx(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 >= L'a') {
				    wc -= (L'a' - L'A');
				    ((WCHAR *) nativePath)[i] = wc;
				}
			    }
			    Tcl_DStringAppend(&dsNorm, (const char *)nativePath,
				    (int)(sizeof(WCHAR) * len));
			    lastValidPathEnd = 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_DStringInit(&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 >= L'a') {
			drive -= (L'a' - L'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 *)
				((WCHAR *)(nativePath + Tcl_DStringLength(&ds))
				- dotLen), (int)(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
		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 TCHAR *nativePath =
	    		Tcl_WinUtfToTChar(path, lastValidPathEnd - path, &ds);
	    DWORD wpathlen = GetLongPathNameProc(nativePath,
		    (TCHAR *) wpath, MAX_PATH);

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

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

    /*
     * 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_DString dsTemp;

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

	    int len;
	    char *path;
	    Tcl_Obj *tmpPathPtr;

	    tmpPathPtr = Tcl_NewStringObj(Tcl_DStringValue(&dsTemp),
		    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(&dsTemp),
		    nextCheckpoint);
	}
	Tcl_DStringFree(&dsTemp);
    }
    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((const 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 may need to be normalized.
 *
 *---------------------------------------------------------------------------
 */

ClientData
TclNativeCreateNativeRep(
    Tcl_Obj *pathPtr)
{
    char *nativePathPtr, *str;
    Tcl_DString ds;
    Tcl_Obj *validPathPtr;
    int len;

    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;
	}
    } else {
	/*
	 * Make sure the normalized path is set.
	 */

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

    str = Tcl_GetStringFromObj(validPathPtr, &len);
    if (str[0] == '/' && str[1] == '/' && str[2] == '?' && str[3] == '/') {
	char *p;

	for (p = str; p && *p; ++p) {
	    if (*p == '/') {
		*p = '\\';
	    }
	}
    }
    Tcl_WinUtfToTChar(str, len, &ds);
    len = Tcl_DStringLength(&ds) + sizeof(WCHAR);
    Tcl_DecrRefCount(validPathPtr);
    nativePathPtr = ckalloc((unsigned) len);
    memcpy(nativePathPtr, Tcl_DStringValue(&ds), (size_t) len);

    Tcl_DStringFree(&ds);
    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(TCHAR) * (_tcslen((const TCHAR *) 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 TCHAR *native;
    DWORD attr = 0;
    DWORD flags = FILE_ATTRIBUTE_NORMAL;
    FILETIME lastAccessTime, lastModTime;

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

    native = Tcl_FSGetNativePath(pathPtr);

    attr = GetFileAttributes(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 = CreateFile(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;
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */