*
 * Copyright (c) 1991-1994 The Regents of the University of California.
 * Copyright (c) 1994-1997 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: tclIOUtil.c,v 1.77 2003/03/03 20:22:41 das Exp $
 * RCS: @(#) $Id: tclIOUtil.c,v 1.78 2003/04/11 15:59:54 vincentdarley Exp $
 */

#include "tclInt.h"
#include "tclPort.h"
#ifdef MAC_TCL
#include "tclMacInt.h"
#endif
#ifdef __WIN32__
/* for tclWinProcs->useWide */
#include "tclWinInt.h"
#endif
#include "tclFileSystem.h"

/*
 * Prototypes for procedures defined later in this file.
 */

static void		DupFsPathInternalRep _ANSI_ARGS_((Tcl_Obj *srcPtr,
			    Tcl_Obj *copyPtr));
static void		FreeFsPathInternalRep _ANSI_ARGS_((Tcl_Obj *listPtr));
static void             UpdateStringOfFsPath _ANSI_ARGS_((Tcl_Obj *objPtr));
static int		SetFsPathFromAny _ANSI_ARGS_((Tcl_Interp *interp,
			    Tcl_Obj *objPtr));
static Tcl_Obj*         MakeFsPathFromRelative _ANSI_ARGS_((Tcl_Interp *interp, 
			    Tcl_Obj *objPtr, Tcl_Obj *cwdPtr));
static Tcl_Obj*         FSNormalizeAbsolutePath 
                            _ANSI_ARGS_((Tcl_Interp* interp, Tcl_Obj *pathPtr));
static int              TclNormalizeToUniquePath 
                            _ANSI_ARGS_((Tcl_Interp *interp, Tcl_Obj *pathPtr,
					 int startAt));
static int		SetFsPathFromAbsoluteNormalized 
                            _ANSI_ARGS_((Tcl_Interp *interp, Tcl_Obj *objPtr));
static int 		FindSplitPos _ANSI_ARGS_((char *path, char *separator));
static Tcl_PathType     FSGetPathType  _ANSI_ARGS_((Tcl_Obj *pathObjPtr, 
			    Tcl_Filesystem **filesystemPtrPtr, 
static FilesystemRecord* FsGetIterator(void);
			    int *driveNameLengthPtr));
static Tcl_PathType     GetPathType  _ANSI_ARGS_((Tcl_Obj *pathObjPtr, 
static void FsReleaseIterator(void);
			    Tcl_Filesystem **filesystemPtrPtr, 
			    int *driveNameLengthPtr, Tcl_Obj **driveNameRef));

/*
 * Define the 'path' object type, which Tcl uses to represent
 * file paths internally.
 */
Tcl_ObjType tclFsPathType = {
    "path",				/* name */
    FreeFsPathInternalRep,		/* freeIntRepProc */
    DupFsPathInternalRep,	        /* dupIntRepProc */
    UpdateStringOfFsPath,		/* updateStringProc */
    SetFsPathFromAny			/* setFromAnyProc */
};

/* 
 * These form part of the native filesystem support.  They are needed
 * here because we have a few native filesystem functions (which are
 * the same for mac/win/unix) in this file.  There is no need to place
 * them in tclInt.h, because they are not (and should not be) used
 * anywhere else.

static AccessProc *accessProcList = NULL;
static OpenFileChannelProc *openFileChannelProcList = NULL;

TCL_DECLARE_MUTEX(obsoleteFsHookMutex)

#endif /* USE_OBSOLETE_FS_HOOKS */

/* 
 * A filesystem record is used to keep track of each
 * filesystem currently registered with the core,
 * in a linked list.
 */
typedef struct FilesystemRecord {
    ClientData	     clientData;  /* Client specific data for the new
				   * filesystem (can be NULL) */
    Tcl_Filesystem *fsPtr;        /* Pointer to filesystem dispatch
                                   * table. */
    int fileRefCount;             /* How many Tcl_Obj's use this
                                   * filesystem. */
    struct FilesystemRecord *nextPtr;  
                                  /* The next filesystem registered
                                   * to Tcl, or NULL if no more. */
} FilesystemRecord;

static FilesystemRecord* GetFilesystemRecord 
	_ANSI_ARGS_((Tcl_Filesystem *fromFilesystem, int *epoch));

/* 
 * Declare the native filesystem support.  These functions should
 * be considered private to Tcl, and should really not be called
 * directly by any code other than this file (i.e. neither by
 * Tcl's core nor by extensions).  Similarly, the old string-based
 * Tclp... native filesystem functions should not be called.
 * 
 * The correct API to use now is the Tcl_FS... set of functions,
 * which ensure correct and complete virtual filesystem support.
 * 
 * We cannot make all of these static, since some of them
 * are implemented in the platform-specific directories.
 */
static Tcl_FSPathInFilesystemProc NativePathInFilesystem;
static Tcl_FSFilesystemSeparatorProc NativeFilesystemSeparator;
static Tcl_FSFreeInternalRepProc NativeFreeInternalRep;
static Tcl_FSDupInternalRepProc NativeDupInternalRep;
Tcl_FSDupInternalRepProc NativeDupInternalRep;
static Tcl_FSCreateInternalRepProc NativeCreateNativeRep;
static Tcl_FSFileAttrStringsProc NativeFileAttrStrings;
static Tcl_FSFileAttrsGetProc NativeFileAttrsGet;
static Tcl_FSFileAttrsSetProc NativeFileAttrsSet;

/* 
 * The only reason these functions are not static is that they

 * Define the native filesystem dispatch table.  If necessary, it
 * is ok to make this non-static, but it should only be accessed
 * by the functions actually listed within it (or perhaps other
 * helper functions of them).  Anything which is not part of this
 * 'native filesystem implementation' should not be delving inside
 * here!
 */
static Tcl_Filesystem tclNativeFilesystem = {
Tcl_Filesystem tclNativeFilesystem = {
    "native",
    sizeof(Tcl_Filesystem),
    TCL_FILESYSTEM_VERSION_1,
    &NativePathInFilesystem,
    &NativeDupInternalRep,
    &NativeFreeInternalRep,
    &TclpNativeToNormalized,

 */

/* 
 * This is incremented each time we modify the linked list of
 * filesystems.  Any time it changes, all cached filesystem
 * representations are suspect and must be freed.
 */
static int theFilesystemEpoch = 0;
int theFilesystemEpoch = 0;

/*
 * Stores the linked list of filesystems.
 */
static FilesystemRecord *filesystemList = &nativeFilesystemRecord;

/* 

#ifdef TCL_THREADS
static Tcl_Condition filesystemOkToModify = NULL;
#endif

TCL_DECLARE_MUTEX(filesystemMutex)

/* 
 * struct FsPath --
 * 
 * Internal representation of a Tcl_Obj of "path" type.  This
 * can be used to represent relative or absolute paths, and has
 * certain optimisations when used to represent paths which are
 * already normalized and absolute.
 * 
 * Note that 'normPathPtr' can be a circular reference to the
 * container Tcl_Obj of this FsPath.
 */
typedef struct FsPath {
    Tcl_Obj *translatedPathPtr; /* Name without any ~user sequences.
                                 * If this is NULL, then this is a 
                                 * pure normalized, absolute path
                                 * object, in which the parent Tcl_Obj's
                                 * string rep is already both translated
                                 * and normalized. */
    Tcl_Obj *normPathPtr;       /* Normalized absolute path, without 
                                 * ., .. or ~user sequences. If the 
                                 * Tcl_Obj containing 
				 * this FsPath is already normalized, 
				 * this may be a circular reference back
				 * to the container.  If that is NOT the
				 * case, we have a refCount on the object. */
    Tcl_Obj *cwdPtr;            /* If null, path is absolute, else
                                 * this points to the cwd object used
				 * for this path.  We have a refCount
				 * on the object. */
    int flags;                  /* Flags to describe interpretation */
    ClientData nativePathPtr;   /* Native representation of this path,
                                 * which is filesystem dependent. */
    int filesystemEpoch;        /* Used to ensure the path representation
                                 * was generated during the correct
				 * filesystem epoch.  The epoch changes
				 * when filesystem-mounts are changed. */ 
    struct FilesystemRecord *fsRecPtr;
                                /* Pointer to the filesystem record 
                                 * entry to use for this path. */
} FsPath;

#define TCLPATH_APPENDED 1
#define TCLPATH_RELATIVE 2
/* 
 * Used to implement Tcl_FSGetCwd in a file-system independent way.
 * This is protected by the cwdMutex below.
 */
static Tcl_Obj* cwdPathPtr = NULL;
TCL_DECLARE_MUTEX(cwdMutex)

/* 

    Tcl_Filesystem *divertedFilesystem;
    ClientData divertedFileNativeRep;
} FsDivertLoad;

/* Now move on to the basic filesystem implementation */


static int 
FsCwdPointerEquals(objPtr)
int 
TclFSCwdPointerEquals(objPtr)
    Tcl_Obj* objPtr;
{
    Tcl_MutexLock(&cwdMutex);
    if (cwdPathPtr == objPtr) {
	Tcl_MutexUnlock(&cwdMutex);
	return 1;
    } else {
	Tcl_MutexUnlock(&cwdMutex);
	return 0;
    }
}
        


static FilesystemRecord* 
FsGetIterator(void) {
    Tcl_MutexLock(&filesystemMutex);
    filesystemIteratorsInProgress++;
    Tcl_MutexUnlock(&filesystemMutex);
    /* Now we know the list of filesystems cannot be modified */

    Tcl_MutexUnlock(&filesystemMutex);
    return (retVal);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSMatchInDirectory --
 *
 *	This routine is used by the globbing code to search a directory
 *	for all files which match a given pattern.  The appropriate
 *	function for the filesystem to which pathPtr belongs will be
 *	called.  If pathPtr does not belong to any filesystem and if it
 *	is NULL or the empty string, then we assume the pattern is to be
 *	matched in the current working directory.  To avoid each
 *	filesystem's Tcl_FSMatchInDirectoryProc having to deal with this
 *	issue, we create a pathPtr on the fly (equal to the cwd), and
 *	then remove it from the results returned.  This makes filesystems
 *	easy to write, since they can assume the pathPtr passed to them
 *	is an ordinary path.  In fact this means we could remove such
 *	special case handling from Tcl's native filesystems.
 *	
 *	If 'pattern' is NULL, then pathPtr is assumed to be a fully
 *	specified path of a single file/directory which must be
 *	checked for existence and correct type.
 *
 * Results: 
 *	
 *	The return value is a standard Tcl result indicating whether an
 *	error occurred in globbing.  Error messages are placed in
 *	interp, but good results are placed in the resultPtr given.
 *	
 *	Recursive searches, e.g.
 *	
 *	   glob -dir $dir -join * pkgIndex.tcl
 *	   
 *	which must recurse through each directory matching '*' are
 *	handled internally by Tcl, by passing specific flags in a 
 *	modified 'types' parameter.  This means the actual filesystem
 *	only ever sees patterns which match in a single directory.
 *
 * Side effects:
 *	The interpreter may have an error message inserted into it.
 *
 *---------------------------------------------------------------------- 
 */

int
Tcl_FSMatchInDirectory(interp, result, pathPtr, pattern, types)
    Tcl_Interp *interp;		/* Interpreter to receive error messages. */
    Tcl_Obj *result;		/* List object to receive 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. */
{
    Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);
    if (fsPtr != NULL) {
	Tcl_FSMatchInDirectoryProc *proc = fsPtr->matchInDirectoryProc;
	if (proc != NULL) {
	    return (*proc)(interp, result, pathPtr, pattern, types);
	}
    } else {
	Tcl_Obj* cwd;
	int ret = -1;
	if (pathPtr != NULL) {
	    int len;
	    Tcl_GetStringFromObj(pathPtr,&len);
	    if (len != 0) {
		/* 
		 * We have no idea how to match files in a directory
		 * which belongs to no known filesystem
		 */
		Tcl_SetErrno(ENOENT);
		return -1;
	    }
	}
	/* 
	 * We have an empty or NULL path.  This is defined to mean we
	 * must search for files within the current 'cwd'.  We
	 * therefore use that, but then since the proc we call will
	 * return results which include the cwd we must then trim it
	 * off the front of each path in the result.  We choose to deal
	 * with this here (in the generic code), since if we don't,
	 * every single filesystem's implementation of
	 * Tcl_FSMatchInDirectory will have to deal with it for us.
	 */
	cwd = Tcl_FSGetCwd(NULL);
	if (cwd == NULL) {
	    if (interp != NULL) {
		Tcl_SetResult(interp, "glob couldn't determine "
			  "the current working directory", TCL_STATIC);
	    }
	    return TCL_ERROR;
	}
	fsPtr = Tcl_FSGetFileSystemForPath(cwd);
	if (fsPtr != NULL) {
	    Tcl_FSMatchInDirectoryProc *proc = fsPtr->matchInDirectoryProc;
	    if (proc != NULL) {
		Tcl_Obj* tmpResultPtr = Tcl_NewListObj(0, NULL);
		Tcl_IncrRefCount(tmpResultPtr);
		ret = (*proc)(interp, tmpResultPtr, cwd, pattern, types);
		if (ret == TCL_OK) {
		    int resLength;

		    ret = Tcl_ListObjLength(interp, tmpResultPtr, &resLength);
		    if (ret == TCL_OK) {
			int i;

			for (i = 0; i < resLength; i++) {
			    Tcl_Obj *elt;
			    
			    Tcl_ListObjIndex(interp, tmpResultPtr, i, &elt);
			    Tcl_ListObjAppendElement(interp, result, 
				TclFSMakePathRelative(interp, elt, cwd));
			}
		    }
		}
		Tcl_DecrRefCount(tmpResultPtr);
	    }
	}
	Tcl_DecrRefCount(cwd);
	return ret;
    }
    Tcl_SetErrno(ENOENT);
    return -1;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSMountsChanged --
 *
 *    Notify the filesystem that the available mounted filesystems
 *    (or within any one filesystem type, the number or location of
 *    mount points) have changed.
 *
 * Results:

 *	This code is based on code from Matt Newman and Jean-Claude
 *	Wippler, with additions from Vince Darley and is copyright 
 *	those respective authors.
 *
 *---------------------------------------------------------------------------
 */
static Tcl_Obj*
FSNormalizeAbsolutePath(interp, pathPtr)
FSNormalizeAbsolutePath(interp, pathPtr, clientDataPtr)
    Tcl_Interp* interp;    /* Interpreter to use */
    Tcl_Obj *pathPtr;      /* Absolute path to normalize */
    ClientData *clientDataPtr;
{
    int splen = 0, nplen, eltLen, i;
    char *eltName;
    Tcl_Obj *retVal;
    Tcl_Obj *split;
    Tcl_Obj *elt;
    

		Tcl_ListObjReplace(NULL, split, nplen, 1, 0, NULL);
	    }
	} else {
	    nplen++;
	}
    }
    if (nplen > 0) {
	ClientData clientData = NULL;
	
	retVal = Tcl_FSJoinPath(split, nplen);
	/* 
	 * Now we have an absolute path, with no '..', '.' sequences,
	 * but it still may not be in 'unique' form, depending on the
	 * platform.  For instance, Unix is case-sensitive, so the
	 * path is ok.  Windows is case-insensitive, and also has the
	 * weird 'longname/shortname' thing (e.g. C:/Program Files/ and
	 * C:/Progra~1/ are equivalent).  MacOS is case-insensitive.
	 * 
	 * Virtual file systems which may be registered may have
	 * other criteria for normalizing a path.
	 */
	Tcl_IncrRefCount(retVal);
	TclNormalizeToUniquePath(interp, retVal, 0);
	TclFSNormalizeToUniquePath(interp, retVal, 0, &clientData);
	/* 
	 * Since we know it is a normalized path, we can
	 * actually convert this object into an FsPath for
	 * actually convert this object into an "path" object for
	 * greater efficiency 
	 */
	SetFsPathFromAbsoluteNormalized(interp, retVal);
	TclFSMakePathFromNormalized(interp, retVal, clientData);
	if (clientDataPtr != NULL) {
	    *clientDataPtr = clientData;
	}
    } else {
	/* Init to an empty string */
	retVal = Tcl_NewStringObj("",0);
	Tcl_IncrRefCount(retVal);
    }
    /* 
     * We increment and then decrement the refCount of split to free

    /* This has a refCount of 1 for the caller */
    return retVal;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclNormalizeToUniquePath --
 * TclFSNormalizeToUniquePath --
 *
 * Description:
 *	Takes a path specification containing no ../, ./ sequences,
 *	and converts it into a unique path for the given platform.
 *      On MacOS, Unix, this means the path must be free of
 *	symbolic links/aliases, and on Windows it means we want the
 *	long form, with that long form's case-dependence (which gives

 *
 *      Important assumption: if startAt is non-zero, it must point
 *      to a directory separator that we know exists and is already
 *      normalized (so it is important not to point to the char just
 *      after the separator).
 *---------------------------------------------------------------------------
 */
static int
TclNormalizeToUniquePath(interp, pathPtr, startAt)
int
TclFSNormalizeToUniquePath(interp, pathPtr, startAt, clientDataPtr)
    Tcl_Interp *interp;
    Tcl_Obj *pathPtr;
    int startAt;
    ClientData *clientDataPtr;
{
    FilesystemRecord *fsRecPtr;
    /* Ignore this variable */
    (void)clientDataPtr;

    
    /*
     * Call each of the "normalise path" functions in succession. This is
     * a special case, in which if we have a native filesystem handler,
     * we call it first.  This is because the root of Tcl's filesystem
     * is always a native filesystem (i.e. '/' on unix is native).
     */

    Tcl_StatBuf statBuf;
    Tcl_Obj *oldScriptFile;
    Interp *iPtr;
    char *string;
    Tcl_Channel chan;
    Tcl_Obj *objPtr;

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

    result = TCL_ERROR;
    objPtr = Tcl_NewObj();

    if (Tcl_FSStat(pathPtr, &statBuf) == -1) {

                                         * a string such as "rw". */
    int permissions;                    /* If the open involves creating a
                                         * file, with what modes to create
                                         * it? */
{
    Tcl_Filesystem *fsPtr;
#ifdef USE_OBSOLETE_FS_HOOKS
    OpenFileChannelProc *openFileChannelProcPtr;
    Tcl_Channel retVal = NULL;
    char *path;
#endif /* USE_OBSOLETE_FS_HOOKS */
    Tcl_Obj *transPtr = Tcl_FSGetTranslatedPath(interp, pathPtr);
    if (transPtr == NULL) {
	return NULL;
    }

#ifdef USE_OBSOLETE_FS_HOOKS
    if (transPtr == NULL) {
	path = NULL;
    } else {
	path = Tcl_GetString(transPtr);
    }

    /*
     * Call each of the "Tcl_OpenFileChannel" function in succession.
     * Call each of the "Tcl_OpenFileChannel" functions in succession.
     * A non-NULL return value indicates the particular function has
     * succeeded.
     */

    Tcl_MutexLock(&obsoleteFsHookMutex);
    if (openFileChannelProcList != NULL) {
	OpenFileChannelProc *openFileChannelProcPtr;
	char *path;
	Tcl_Obj *transPtr = Tcl_FSGetTranslatedPath(interp, pathPtr);
	
	if (transPtr == NULL) {
	    path = NULL;
	} else {
	    path = Tcl_GetString(transPtr);
	}

    openFileChannelProcPtr = openFileChannelProcList;
    while ((retVal == NULL) && (openFileChannelProcPtr != NULL)) {
	retVal = (*openFileChannelProcPtr->proc)(interp, path,
		modeString, permissions);
	openFileChannelProcPtr = openFileChannelProcPtr->nextPtr;
	openFileChannelProcPtr = openFileChannelProcList;
	
	while ((retVal == NULL) && (openFileChannelProcPtr != NULL)) {
	    retVal = (*openFileChannelProcPtr->proc)(interp, path,
						     modeString, permissions);
	    openFileChannelProcPtr = openFileChannelProcPtr->nextPtr;
	}
    }
    Tcl_MutexUnlock(&obsoleteFsHookMutex);
    if (retVal != NULL) {
	return retVal;
    }
#endif /* USE_OBSOLETE_FS_HOOKS */
    
    /* 
     * We need this just to ensure we return the correct error messages
     * under some circumstances.
     */
    if (Tcl_FSGetNormalizedPath(interp, pathPtr) == NULL) {
        return NULL;
    }
    
    fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);
    if (fsPtr != NULL) {
	Tcl_FSOpenFileChannelProc *proc = fsPtr->openFileChannelProc;
	if (proc != NULL) {
	    int mode, seekFlag;
	    mode = TclGetOpenMode(interp, modeString, &seekFlag);
	    if (mode == -1) {

    if (interp != NULL) {
	Tcl_AppendResult(interp, "couldn't open \"", 
			 Tcl_GetString(pathPtr), "\": ",
			 Tcl_PosixError(interp), (char *) NULL);
    }
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSMatchInDirectory --
 *
 *	This routine is used by the globbing code to search a directory
 *	for all files which match a given pattern.  The appropriate
 *	function for the filesystem to which pathPtr belongs will be
 *	called.  If pathPtr does not belong to any filesystem and if it
 *	is NULL or the empty string, then we assume the pattern is to be
 *	matched in the current working directory.  To avoid each
 *	filesystem's Tcl_FSMatchInDirectoryProc having to deal with this
 *	issue, we create a pathPtr on the fly (equal to the cwd), and
 *	then remove it from the results returned.  This makes filesystems
 *	easy to write, since they can assume the pathPtr passed to them
 *	is an ordinary path.  In fact this means we could remove such
 *	special case handling from Tcl's native filesystems.
 *	
 *	If 'pattern' is NULL, then pathPtr is assumed to be a fully
 *	specified path of a single file/directory which must be
 *	checked for existence and correct type.
 *
 * Results: 
 *	
 *	The return value is a standard Tcl result indicating whether an
 *	error occurred in globbing.  Error messages are placed in
 *	interp, but good results are placed in the resultPtr given.
 *	
 *	Recursive searches, e.g.
 *	
 *	   glob -dir $dir -join * pkgIndex.tcl
 *	   
 *	which must recurse through each directory matching '*' are
 *	handled internally by Tcl, by passing specific flags in a 
 *	modified 'types' parameter.  This means the actual filesystem
 *	only ever sees patterns which match in a single directory.
 *
 * Side effects:
 *	The interpreter may have an error message inserted into it.
 *
 *---------------------------------------------------------------------- 
 */

int
Tcl_FSMatchInDirectory(interp, result, pathPtr, pattern, types)
    Tcl_Interp *interp;		/* Interpreter to receive error messages. */
    Tcl_Obj *result;		/* List object to receive 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. */
{
    Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(pathPtr);
    if (fsPtr != NULL) {
	Tcl_FSMatchInDirectoryProc *proc = fsPtr->matchInDirectoryProc;
	if (proc != NULL) {
	    return (*proc)(interp, result, pathPtr, pattern, types);
	}
    } else {
	Tcl_Obj* cwd;
	int ret = -1;
	if (pathPtr != NULL) {
	    int len;
	    Tcl_GetStringFromObj(pathPtr,&len);
	    if (len != 0) {
		/* 
		 * We have no idea how to match files in a directory
		 * which belongs to no known filesystem
		 */
		Tcl_SetErrno(ENOENT);
		return -1;
	    }
	}
	/* 
	 * We have an empty or NULL path.  This is defined to mean we
	 * must search for files within the current 'cwd'.  We
	 * therefore use that, but then since the proc we call will
	 * return results which include the cwd we must then trim it
	 * off the front of each path in the result.  We choose to deal
	 * with this here (in the generic code), since if we don't,
	 * every single filesystem's implementation of
	 * Tcl_FSMatchInDirectory will have to deal with it for us.
	 */
	cwd = Tcl_FSGetCwd(NULL);
	if (cwd == NULL) {
	    if (interp != NULL) {
	        Tcl_SetResult(interp, "glob couldn't determine "
			  "the current working directory", TCL_STATIC);
	    }
	    return TCL_ERROR;
	}
	fsPtr = Tcl_FSGetFileSystemForPath(cwd);
	if (fsPtr != NULL) {
	    Tcl_FSMatchInDirectoryProc *proc = fsPtr->matchInDirectoryProc;
	    if (proc != NULL) {
		int cwdLen;
		char *cwdStr;
		Tcl_Obj* tmpResultPtr = Tcl_NewListObj(0, NULL);
		Tcl_IncrRefCount(tmpResultPtr);
		/* 
		 * We know the cwd is a normalised object which does
		 * not end in a directory delimiter, unless the cwd
		 * is the name of a volume, in which case it will
		 * end in a delimiter!  We handle this situation here.
		 * A better test than the '!= sep' might be to simply
		 * check if 'cwd' is a root volume.
		 * 
		 * Note that if we get this wrong, we will strip off
		 * either too much or too little below, leading to
		 * wrong answers returned by glob.
		 */
		cwdStr = Tcl_GetStringFromObj(cwd, &cwdLen);
		/* 
		 * Should we perhaps use 'Tcl_FSPathSeparator'?
		 * But then what about the Windows special case?
		 * Perhaps we should just check if cwd is a root
		 * volume.
		 */
		switch (tclPlatform) {
		    case TCL_PLATFORM_UNIX:
			if (cwdStr[cwdLen-1] != '/') {
			    cwdLen++;
			}
			break;
		    case TCL_PLATFORM_WINDOWS:
			if (cwdStr[cwdLen-1] != '/' 
				&& cwdStr[cwdLen-1] != '\\') {
			    cwdLen++;
			}
			break;
		    case TCL_PLATFORM_MAC:
			if (cwdStr[cwdLen-1] != ':') {
			    cwdLen++;
			}
			break;
		}
		ret = (*proc)(interp, tmpResultPtr, cwd, pattern, types);
		if (ret == TCL_OK) {
		    int resLength;

		    ret = Tcl_ListObjLength(interp, tmpResultPtr, &resLength);
		    if (ret == TCL_OK) {
			int i;

			for (i = 0; i < resLength; i++) {
			    Tcl_Obj *cutElt, *elt;
			    char *eltStr;
			    int eltLen;
			    
			    Tcl_ListObjIndex(interp, tmpResultPtr, i, &elt);
			    if (elt->typePtr == &tclFsPathType) {
				FsPath* fsPathPtr = (FsPath*) 
				                elt->internalRep.otherValuePtr;
				if (fsPathPtr->flags != 0 
					&& fsPathPtr->cwdPtr == cwd) {
				    Tcl_ListObjAppendElement(interp, result, 
					MakeFsPathFromRelative(interp, 
						fsPathPtr->normPathPtr, cwd));
				    continue;
				}
			    }
			    eltStr = Tcl_GetStringFromObj(elt, &eltLen);
			    cutElt = Tcl_NewStringObj(eltStr + cwdLen,
				    eltLen - cwdLen);
			    Tcl_ListObjAppendElement(interp, result, cutElt);
			}
		    }
		}
		Tcl_DecrRefCount(tmpResultPtr);
	    }
	}
	Tcl_DecrRefCount(cwd);
	return ret;
    }
    Tcl_SetErrno(ENOENT);
    return -1;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSGetCwd --
 *
 *	This function replaces the library version of getcwd().
 *	
 *	Most VFS's will *not* implement a 'cwdProc'.  Tcl now maintains
 *	its own record (in a Tcl_Obj) of the cwd, and an attempt
 *	is made to synchronise this with the cwd's containing filesystem,
 *	if that filesystem provides a cwdProc (e.g. the native filesystem).
 *	
 *	Note that if Tcl's cwd is not in the native filesystem, then of
 *	course Tcl's cwd and the native cwd are different: extensions
 *	should therefore ensure they only access the cwd through this
 *	function to avoid confusion.
 *	
 *	If a global cwdPathPtr already exists, it is returned, subject
 *	to a synchronisation attempt in that cwdPathPtr's fs.
 *	Otherwise, the chain of functions that have been "inserted"
 *	into the filesystem will be called in succession until either a
 *	value other than NULL is returned, or the entire list is
 *	visited.
 *
 * Results:
 *	The result is a pointer to a Tcl_Obj 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.  
 *	
 *	The result already has its refCount incremented for the caller.
 *	When it is no longer needed, that refCount should be decremented.
 *	This is needed for thread-safety purposes, to allow multiple
 *	threads to access this and related functions, while ensuring the
 *	results are always valid.
 *	
 *	Of course it is probably a bad idea for multiple threads to
 *	be *setting* the cwd anyway, but we can at least try to 
 *	help the case of multiple reads with occasional sets.
 *
 * Side effects:
 *	Various objects may be freed and allocated.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj*
Tcl_FSGetCwd(interp)
    Tcl_Interp *interp;
{
    Tcl_Obj *cwdToReturn;
    
    if (FsCwdPointerEquals(NULL)) {
	FilesystemRecord *fsRecPtr;
	Tcl_Obj *retVal = NULL;

        /* 
         * We've never been called before, try to find a cwd.  Call
         * each of the "Tcl_GetCwd" function in succession.  A non-NULL
         * return value indicates the particular function has
         * succeeded.
	 */

	fsRecPtr = FsGetIterator();
	while ((retVal == NULL) && (fsRecPtr != NULL)) {
	    Tcl_FSGetCwdProc *proc = fsRecPtr->fsPtr->getCwdProc;
	    if (proc != NULL) {
		retVal = (*proc)(interp);
	    }
	    fsRecPtr = fsRecPtr->nextPtr;
	}
	FsReleaseIterator();
	/* 
	 * Now the 'cwd' may NOT be normalized, at least on some
	 * platforms.  For the sake of efficiency, we want a completely
	 * normalized cwd at all times.
	 * 
	 * Finally, if retVal is NULL, we do not have a cwd, which
	 * could be problematic.
	 */
	if (retVal != NULL) {
	    Tcl_Obj *norm = FSNormalizeAbsolutePath(interp, retVal);
	    if (norm != NULL) {
		/* 
		 * We found a cwd, which is now in our global storage.
		 * We must make a copy.  Norm already has a refCount of
		 * 1.
		 * 
		 * Threading issue: note that multiple threads at system
		 * startup could in principle call this procedure 
		 * simultaneously.  They will therefore each set the
		 * cwdPathPtr independently.  That behaviour is a bit
		 * peculiar, but should be fine.  Once we have a cwd,
		 * we'll always be in the 'else' branch below which
		 * is simpler.
		 */
		Tcl_MutexLock(&cwdMutex);
		/* Just in case the pointer has been set by another
		 * thread between now and the test above */
		if (cwdPathPtr != NULL) {
		    Tcl_DecrRefCount(cwdPathPtr);
		}
		cwdPathPtr = norm;
		Tcl_MutexUnlock(&cwdMutex);
	    }
	    Tcl_DecrRefCount(retVal);
	}
    } else {
	/* 
	 * We already have a cwd cached, but we want to give the
	 * filesystem it is in a chance to check whether that cwd
	 * has changed, or is perhaps no longer accessible.  This
	 * allows an error to be thrown if, say, the permissions on
	 * that directory have changed.
	 */
	Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(cwdPathPtr);
	/* 
	 * If the filesystem couldn't be found, or if no cwd function
	 * exists for this filesystem, then we simply assume the cached
	 * cwd is ok.  If we do call a cwd, we must watch for errors
	 * (if the cwd returns NULL).  This ensures that, say, on Unix
	 * if the permissions of the cwd change, 'pwd' does actually
	 * throw the correct error in Tcl.  (This is tested for in the
	 * test suite on unix).
	 */
	if (fsPtr != NULL) {
	    Tcl_FSGetCwdProc *proc = fsPtr->getCwdProc;
	    if (proc != NULL) {
		Tcl_Obj *retVal = (*proc)(interp);
		if (retVal != NULL) {
		    Tcl_Obj *norm = FSNormalizeAbsolutePath(interp, retVal);
		    /* 
		     * Check whether cwd has changed from the value
		     * previously stored in cwdPathPtr.  Really 'norm'
		     * shouldn't be null, but we are careful.
		     */
		    if (norm == NULL) {
			/* Do nothing */
		    } else if (Tcl_FSEqualPaths(cwdPathPtr, norm)) {
		        /* 
		         * If the paths were equal, we can be more
		         * efficient and retain the old path object
		         * which will probably already be shared.  In
		         * this case we can simply free the normalized
		         * path we just calculated.
		         */
		        Tcl_DecrRefCount(norm);
		    } else {
			/* The cwd has in fact changed, so we must
			 * lock down the cwdMutex to modify. */
			Tcl_MutexLock(&cwdMutex);
			Tcl_DecrRefCount(cwdPathPtr);
			cwdPathPtr = norm;
			Tcl_MutexUnlock(&cwdMutex);
		    }
		    Tcl_DecrRefCount(retVal);
		} else {
		    /* The 'cwd' function returned an error, so we
		     * reset the cwd after locking down the mutex. */
		    Tcl_MutexLock(&cwdMutex);
		    Tcl_DecrRefCount(cwdPathPtr);
		    cwdPathPtr = NULL;
		    Tcl_MutexUnlock(&cwdMutex);
		}
	    }
	}
    }
    
    /* 
     * The paths all eventually fall through to here.  Note that
     * we use a bunch of separate mutex locks throughout this
     * code to help prevent deadlocks between threads.  Really
     * the only weirdness will arise if multiple threads are setting
     * and reading the cwd, and that behaviour is always going to be
     * a little suspect.
     */
    Tcl_MutexLock(&cwdMutex);
    cwdToReturn = cwdPathPtr;
    if (cwdToReturn != NULL) {
        Tcl_IncrRefCount(cwdToReturn);
    }
    Tcl_MutexUnlock(&cwdMutex);
    
    return (cwdToReturn);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSUtime --
 *
 *	This procedure replaces the library version of utime.

    Tcl_SetErrno(ENOENT);
    return -1;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSGetCwd --
 *
 *	This function replaces the library version of getcwd().
 *	
 *	Most VFS's will *not* implement a 'cwdProc'.  Tcl now maintains
 *	its own record (in a Tcl_Obj) of the cwd, and an attempt
 *	is made to synchronise this with the cwd's containing filesystem,
 *	if that filesystem provides a cwdProc (e.g. the native filesystem).
 *	
 *	Note that if Tcl's cwd is not in the native filesystem, then of
 *	course Tcl's cwd and the native cwd are different: extensions
 *	should therefore ensure they only access the cwd through this
 *	function to avoid confusion.
 *	
 *	If a global cwdPathPtr already exists, it is returned, subject
 *	to a synchronisation attempt in that cwdPathPtr's fs.
 *	Otherwise, the chain of functions that have been "inserted"
 *	into the filesystem will be called in succession until either a
 *	value other than NULL is returned, or the entire list is
 *	visited.
 *
 * Results:
 *	The result is a pointer to a Tcl_Obj 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.  
 *	
 *	The result already has its refCount incremented for the caller.
 *	When it is no longer needed, that refCount should be decremented.
 *	This is needed for thread-safety purposes, to allow multiple
 *	threads to access this and related functions, while ensuring the
 *	results are always valid.
 *	
 *	Of course it is probably a bad idea for multiple threads to
 *	be *setting* the cwd anyway, but we can at least try to 
 *	help the case of multiple reads with occasional sets.
 *
 * Side effects:
 *	Various objects may be freed and allocated.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj*
Tcl_FSGetCwd(interp)
    Tcl_Interp *interp;
{
    Tcl_Obj *cwdToReturn;
    
    if (TclFSCwdPointerEquals(NULL)) {
	FilesystemRecord *fsRecPtr;
	Tcl_Obj *retVal = NULL;

	/* 
	 * We've never been called before, try to find a cwd.  Call
	 * each of the "Tcl_GetCwd" function in succession.  A non-NULL
	 * return value indicates the particular function has
	 * succeeded.
	 */

	fsRecPtr = FsGetIterator();
	while ((retVal == NULL) && (fsRecPtr != NULL)) {
	    Tcl_FSGetCwdProc *proc = fsRecPtr->fsPtr->getCwdProc;
	    if (proc != NULL) {
		retVal = (*proc)(interp);
	    }
	    fsRecPtr = fsRecPtr->nextPtr;
	}
	FsReleaseIterator();
	/* 
	 * Now the 'cwd' may NOT be normalized, at least on some
	 * platforms.  For the sake of efficiency, we want a completely
	 * normalized cwd at all times.
	 * 
	 * Finally, if retVal is NULL, we do not have a cwd, which
	 * could be problematic.
	 */
	if (retVal != NULL) {
	    Tcl_Obj *norm = FSNormalizeAbsolutePath(interp, retVal, NULL);
	    if (norm != NULL) {
		/* 
		 * We found a cwd, which is now in our global storage.
		 * We must make a copy.  Norm already has a refCount of
		 * 1.
		 * 
		 * Threading issue: note that multiple threads at system
		 * startup could in principle call this procedure 
		 * simultaneously.  They will therefore each set the
		 * cwdPathPtr independently.  That behaviour is a bit
		 * peculiar, but should be fine.  Once we have a cwd,
		 * we'll always be in the 'else' branch below which
		 * is simpler.
		 */
		Tcl_MutexLock(&cwdMutex);
		/* Just in case the pointer has been set by another
		 * thread between now and the test above */
		if (cwdPathPtr != NULL) {
		    Tcl_DecrRefCount(cwdPathPtr);
		}
		cwdPathPtr = norm;
		Tcl_MutexUnlock(&cwdMutex);
	    }
	    Tcl_DecrRefCount(retVal);
	}
    } else {
	/* 
	 * We already have a cwd cached, but we want to give the
	 * filesystem it is in a chance to check whether that cwd
	 * has changed, or is perhaps no longer accessible.  This
	 * allows an error to be thrown if, say, the permissions on
	 * that directory have changed.
	 */
	Tcl_Filesystem *fsPtr = Tcl_FSGetFileSystemForPath(cwdPathPtr);
	/* 
	 * If the filesystem couldn't be found, or if no cwd function
	 * exists for this filesystem, then we simply assume the cached
	 * cwd is ok.  If we do call a cwd, we must watch for errors
	 * (if the cwd returns NULL).  This ensures that, say, on Unix
	 * if the permissions of the cwd change, 'pwd' does actually
	 * throw the correct error in Tcl.  (This is tested for in the
	 * test suite on unix).
	 */
	if (fsPtr != NULL) {
	    Tcl_FSGetCwdProc *proc = fsPtr->getCwdProc;
	    if (proc != NULL) {
		Tcl_Obj *retVal = (*proc)(interp);
		if (retVal != NULL) {
		    Tcl_Obj *norm = FSNormalizeAbsolutePath(interp, retVal, NULL);
		    /* 
		     * Check whether cwd has changed from the value
		     * previously stored in cwdPathPtr.  Really 'norm'
		     * shouldn't be null, but we are careful.
		     */
		    if (norm == NULL) {
			/* Do nothing */
		    } else if (Tcl_FSEqualPaths(cwdPathPtr, norm)) {
			/* 
			 * If the paths were equal, we can be more
			 * efficient and retain the old path object
			 * which will probably already be shared.  In
			 * this case we can simply free the normalized
			 * path we just calculated.
			 */
			Tcl_DecrRefCount(norm);
		    } else {
			/* The cwd has in fact changed, so we must
			 * lock down the cwdMutex to modify. */
			Tcl_MutexLock(&cwdMutex);
			Tcl_DecrRefCount(cwdPathPtr);
			cwdPathPtr = norm;
			Tcl_MutexUnlock(&cwdMutex);
		    }
		    Tcl_DecrRefCount(retVal);
		} else {
		    /* The 'cwd' function returned an error, so we
		     * reset the cwd after locking down the mutex. */
		    Tcl_MutexLock(&cwdMutex);
		    Tcl_DecrRefCount(cwdPathPtr);
		    cwdPathPtr = NULL;
		    Tcl_MutexUnlock(&cwdMutex);
		}
	    }
	}
    }
    
    /* 
     * The paths all eventually fall through to here.  Note that
     * we use a bunch of separate mutex locks throughout this
     * code to help prevent deadlocks between threads.  Really
     * the only weirdness will arise if multiple threads are setting
     * and reading the cwd, and that behaviour is always going to be
     * a little suspect.
     */
    Tcl_MutexLock(&cwdMutex);
    cwdToReturn = cwdPathPtr;
    if (cwdToReturn != NULL) {
	Tcl_IncrRefCount(cwdToReturn);
    }
    Tcl_MutexUnlock(&cwdMutex);
    
    return (cwdToReturn);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSChdir --
 *
 *	This function replaces the library version of chdir().
 *	
 *	The path is normalized and then passed to the filesystem
 *	which claims it.
 *

	    if (cwdPathPtr != NULL) {
		Tcl_DecrRefCount(cwdPathPtr);
	    }
	    /* Now remember the current cwd */
	    cwdPathPtr = normDirName;
	    Tcl_MutexUnlock(&cwdMutex);
	}
    } else {
	Tcl_SetErrno(ENOENT);
    }
    
    return (retVal);
}

/*
 *----------------------------------------------------------------------

	}
	fsRecPtr = fsRecPtr->nextPtr;
    }
    FsReleaseIterator();
    
    return resultPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FSGetPathType --
 *
 *	Determines whether a given path is relative to the current
 *	directory, relative to the current volume, or absolute.  
 *
 * Results:
 *	Returns one of TCL_PATH_ABSOLUTE, TCL_PATH_RELATIVE, or
 *	TCL_PATH_VOLUME_RELATIVE.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_PathType
Tcl_FSGetPathType(pathObjPtr)
    Tcl_Obj *pathObjPtr;
{
    return FSGetPathType(pathObjPtr, NULL, NULL);
}

/*
 *----------------------------------------------------------------------
 *
 * FSGetPathType --
 *
 *	Determines whether a given path is relative to the current
 *	directory, relative to the current volume, or absolute.  If the
 *	caller wishes to know which filesystem claimed the path (in the
 *	case for which the path is absolute), then a reference to a
 *	filesystem pointer can be passed in (but passing NULL is
 *	acceptable).
 *
 * Results:
 *	Returns one of TCL_PATH_ABSOLUTE, TCL_PATH_RELATIVE, or
 *	TCL_PATH_VOLUME_RELATIVE.  The filesystem reference will
 *	be set if and only if it is non-NULL and the function's 
 *	return value is TCL_PATH_ABSOLUTE.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static Tcl_PathType
FSGetPathType(pathObjPtr, filesystemPtrPtr, driveNameLengthPtr)
    Tcl_Obj *pathObjPtr;
    Tcl_Filesystem **filesystemPtrPtr;
    int *driveNameLengthPtr;
{
    if (Tcl_FSConvertToPathType(NULL, pathObjPtr) != TCL_OK) {
	return GetPathType(pathObjPtr, filesystemPtrPtr, 
			   driveNameLengthPtr, NULL);
    } else {
	FsPath *fsPathPtr = (FsPath*) pathObjPtr->internalRep.otherValuePtr;
	if (fsPathPtr->cwdPtr != NULL) {
	    if (fsPathPtr->flags == 0) {
	        return TCL_PATH_RELATIVE;
	    }
	    return FSGetPathType(fsPathPtr->cwdPtr, filesystemPtrPtr, 
				 driveNameLengthPtr);
	} else {
	    return GetPathType(pathObjPtr, filesystemPtrPtr, 
			       driveNameLengthPtr, NULL);
	}
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSSplitPath --
 *
 *      This function takes the given Tcl_Obj, which should be a valid

    if (lenPtr != NULL) {
	Tcl_ListObjLength(NULL, result, lenPtr);
    }
    return result;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSJoinPath --
 *
 *      This function takes the given Tcl_Obj, which should be a valid
 *      list, and returns the path object given by considering the
 *      first 'elements' elements as valid path segments.  If elements < 0,
 *      we use the entire list.
 *      
 * Results:
 *      Returns object with refCount of zero, (or if non-zero, it has
 *      references elsewhere in Tcl).  Either way, the caller must
 *      increment its refCount before use.
 *
 * Side effects:
/* Simple helper function */
 *	None.
 *
 *---------------------------------------------------------------------------
 */
Tcl_Obj* 
Tcl_FSJoinPath(listObj, elements)
    Tcl_Obj *listObj;
    int elements;
{
    Tcl_Obj *res;
    int i;
    Tcl_Filesystem *fsPtr = NULL;
    
TclFSInternalToNormalized(fromFilesystem, clientData, fsRecPtrPtr, epochPtr)
    Tcl_Filesystem *fromFilesystem;
    ClientData clientData;
    if (elements < 0) {
	if (Tcl_ListObjLength(NULL, listObj, &elements) != TCL_OK) {
	    return NULL;
	}
    } else {
	/* Just make sure it is a valid list */
	int listTest;
    FilesystemRecord **fsRecPtrPtr;
    int *epochPtr;
	if (Tcl_ListObjLength(NULL, listObj, &listTest) != TCL_OK) {
	    return NULL;
	}
	/* 
	 * Correct this if it is too large, otherwise we will
	 * waste our time joining null elements to the path 
	 */
	if (elements > listTest) {
	    elements = listTest;
	}
    }
    
{
    if (elements == 2) {
	/* 
	 * This is a special case where we can be much more
	 * efficient
	 */
	Tcl_Obj *base;
	
    FilesystemRecord *fsRecPtr = FsGetIterator();
	Tcl_ListObjIndex(NULL, listObj, 0, &base);
	/* 
	 * There is only any value in doing this if the first object is
	 * of path type, otherwise we'll never actually get any
	 * efficiency benefit elsewhere in the code (from re-using the
	 * normalized representation of the base object).
	 */
	if (base->typePtr == &tclFsPathType
		&& !(base->bytes != NULL && base->bytes[0] == '\0')) {
    while (fsRecPtr != NULL) {
	    Tcl_Obj *tail;
	    Tcl_PathType type;
	    Tcl_ListObjIndex(NULL, listObj, 1, &tail);
	    type = GetPathType(tail, NULL, NULL, NULL);
	    if (type == TCL_PATH_RELATIVE) {
	if (fsRecPtr->fsPtr == fromFilesystem) {
		CONST char *str;
		int len;
		str = Tcl_GetStringFromObj(tail,&len);
	    *epochPtr = theFilesystemEpoch;
	    *fsRecPtrPtr = fsRecPtr;
		if (len == 0) {
		    /* 
		     * This happens if we try to handle the root volume
		     * '/'.  There's no need to return a special path
		     * object, when the base itself is just fine!
		     */
		    return base;
	    break;
		}
		if (str[0] != '.') {
		    return TclNewFSPathObj(base, str, len);
		}
		/* 
		 * Otherwise we don't have an easy join, and
		 * we must let the more general code below handle
		 * things
		 */
	    } else {
		return tail;
	    }
	}
    }
    
	fsRecPtr = fsRecPtr->nextPtr;
    res = Tcl_NewObj();
    
    }
    for (i = 0; i < elements; i++) {
	Tcl_Obj *elt;
	int driveNameLength;
	Tcl_PathType type;
	char *strElt;
	int strEltLen;
	int length;
	char *ptr;
	Tcl_Obj *driveName = NULL;
	
    FsReleaseIterator();
	Tcl_ListObjIndex(NULL, listObj, i, &elt);
	strElt = Tcl_GetStringFromObj(elt, &strEltLen);
	type = GetPathType(elt, &fsPtr, &driveNameLength, &driveName);
	if (type != TCL_PATH_RELATIVE) {
	    /* Zero out the current result */
	    Tcl_DecrRefCount(res);
	    if (driveName != NULL) {
	        res = Tcl_DuplicateObj(driveName);
		Tcl_DecrRefCount(driveName);
	    } else {
		res = Tcl_NewStringObj(strElt, driveNameLength);
	    }
    
	    strElt += driveNameLength;
	}
	
    if ((fsRecPtr != NULL) 
	ptr = Tcl_GetStringFromObj(res, &length);
	
      && (fromFilesystem->internalToNormalizedProc != NULL)) {
	/* 
	 * Strip off any './' before a tilde, unless this is the
	 * beginning of the path.
	 */
	if (length > 0 && strEltLen > 0) {
	    if ((strElt[0] == '.') && (strElt[1] == '/') 
	      && (strElt[2] == '~')) {
		strElt += 2;
	    }
	}

	return (*fromFilesystem->internalToNormalizedProc)(clientData);
	/* 
	 * A NULL value for fsPtr at this stage basically means
	 * we're trying to join a relative path onto something
	 * which is also relative (or empty).  There's nothing
	 * particularly wrong with that.
	 */
	if (*strElt == '\0') continue;
	
	if (fsPtr == &tclNativeFilesystem || fsPtr == NULL) {
	    TclpNativeJoinPath(res, strElt);
	} else {
    } else {
	    char separator = '/';
	    int needsSep = 0;
	    
	return NULL;
	    if (fsPtr->filesystemSeparatorProc != NULL) {
		Tcl_Obj *sep = (*fsPtr->filesystemSeparatorProc)(res);
		if (sep != NULL) {
		    separator = Tcl_GetString(sep)[0];
		}
    }
	    }

	    if (length > 0 && ptr[length -1] != '/') {
	        Tcl_AppendToObj(res, &separator, 1);
		length++;
	    }
	    Tcl_SetObjLength(res, length + (int) strlen(strElt));
	    
	    ptr = Tcl_GetString(res) + length;
	    for (; *strElt != '\0'; strElt++) {
		if (*strElt == separator) {
		    while (strElt[1] == separator) {
			strElt++;
		    }
		    if (strElt[1] != '\0') {
			if (needsSep) {
			    *ptr++ = separator;
			}
		    }
		} else {
		    *ptr++ = *strElt;
		    needsSep = 1;
		}
	    }
	    length = ptr - Tcl_GetString(res);
	    Tcl_SetObjLength(res, length);
	}
    }
    return res;
}

/*
 *----------------------------------------------------------------------
 *
 * GetPathType --
 *

 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static Tcl_PathType
Tcl_PathType
GetPathType(pathObjPtr, filesystemPtrPtr, driveNameLengthPtr, driveNameRef)
    Tcl_Obj *pathObjPtr;
    Tcl_Filesystem **filesystemPtrPtr;
    int *driveNameLengthPtr;
    Tcl_Obj **driveNameRef;
{
    FilesystemRecord *fsRecPtr;

    Tcl_SetErrno(ENOENT);
    return -1;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSConvertToPathType --
 *
 *      This function tries to convert the given Tcl_Obj to a valid
 *      Tcl path type, taking account of the fact that the cwd may
 *      have changed even if this object is already supposedly of
 *      the correct type.
 *      
 *      The filename may begin with "~" (to indicate current user's
 *      home directory) or "~<user>" (to indicate any user's home
 *      directory).
 *
 * Results:
 *      Standard Tcl error code.
 *
 * Side effects:
 *	The old representation may be freed, and new memory allocated.
 *
 *---------------------------------------------------------------------------
 */
int 
Tcl_FSConvertToPathType(interp, objPtr)
    Tcl_Interp *interp;		/* Interpreter in which to store error
				 * message (if necessary). */
    Tcl_Obj *objPtr;		/* Object to convert to a valid, current
                    		 * path type. */
{
    /* 
     * While it is bad practice to examine an object's type directly,
     * this is actually the best thing to do here.  The reason is that
     * if we are converting this object to FsPath type for the first
     * time, we don't need to worry whether the 'cwd' has changed.
     * On the other hand, if this object is already of FsPath type,
     * and is a relative path, we do have to worry about the cwd.
     * If the cwd has changed, we must recompute the path.
     */
    if (objPtr->typePtr == &tclFsPathType) {
	FsPath *fsPathPtr = (FsPath*) objPtr->internalRep.otherValuePtr;
	if (fsPathPtr->filesystemEpoch != theFilesystemEpoch) {
	    if (objPtr->bytes == NULL) {
		UpdateStringOfFsPath(objPtr);
	    }
	    FreeFsPathInternalRep(objPtr);
	    objPtr->typePtr = NULL;
	    return Tcl_ConvertToType(interp, objPtr, &tclFsPathType);
	}
	return TCL_OK;
	/* 
	 * This code is intentionally never reached.  Once fs-optimisation
	 * is complete, it will be removed/replaced
	 */
	if (fsPathPtr->cwdPtr == NULL) {
	    return TCL_OK;
	} else {
	    if (FsCwdPointerEquals(fsPathPtr->cwdPtr)) {
		return TCL_OK;
	    } else {
		if (objPtr->bytes == NULL) {
		    UpdateStringOfFsPath(objPtr);
		}
		FreeFsPathInternalRep(objPtr);
		objPtr->typePtr = NULL;
		return Tcl_ConvertToType(interp, objPtr, &tclFsPathType);
	    }
	}
    } else {
	return Tcl_ConvertToType(interp, objPtr, &tclFsPathType);
    }
}


 * Tcl_FSGetFileSystemForPath --
 *
/* 
 * Helper function for SetFsPathFromAny.  Returns position of first
 * directory delimiter in the path.
 */
static int
FindSplitPos(path, separator)
    char *path;
    char *separator;
{
    int count = 0;
    switch (tclPlatform) {
	case TCL_PLATFORM_UNIX:
	case TCL_PLATFORM_MAC:
	    while (path[count] != 0) {
	        if (path[count] == *separator) {
	            return count;
	        }
	        count++;
	    }
	    break;

 *      This function determines which filesystem to use for a
	case TCL_PLATFORM_WINDOWS:
	    while (path[count] != 0) {
		if (path[count] == *separator || path[count] == '\\') {
		    return count;
		}
		count++;
	    }
	    break;
    }
    return count;
}

 *      particular path object, and returns the filesystem which
/*
 *---------------------------------------------------------------------------
 *
 * UpdateStringOfFsPath --
 *
 *      Gives an object a valid string rep.
 *      
 * Results:
 *      None.
 *
 * Side effects:
 *	Memory may be allocated.
 *
 *---------------------------------------------------------------------------
 */

 *      accepts this file.  If no filesystem will accept this object
static void
UpdateStringOfFsPath(objPtr)
    register Tcl_Obj *objPtr;	/* path obj with string rep to update. */
{
    register FsPath* fsPathPtr = 
      (FsPath*) objPtr->internalRep.otherValuePtr;
    CONST char *cwdStr;
    int cwdLen;
    Tcl_Obj *copy;
    
    if (fsPathPtr->flags == 0 || fsPathPtr->cwdPtr == NULL) {
        panic("Called UpdateStringOfFsPath with invalid object");
    }
    
    copy = Tcl_DuplicateObj(fsPathPtr->cwdPtr);
    Tcl_IncrRefCount(copy);
    
    cwdStr = Tcl_GetStringFromObj(copy, &cwdLen);
    /* 
     * Should we perhaps use 'Tcl_FSPathSeparator'?
     * But then what about the Windows special case?
     * Perhaps we should just check if cwd is a root volume.
     * We should never get cwdLen == 0 in this code path.
     */
    switch (tclPlatform) {
	case TCL_PLATFORM_UNIX:
	    if (cwdStr[cwdLen-1] != '/') {
		Tcl_AppendToObj(copy, "/", 1);
		cwdLen++;
	    }
	    break;
	case TCL_PLATFORM_WINDOWS:
	    /* 
	     * We need the extra 'cwdLen != 2', and ':' checks because 
	     * a volume relative path doesn't get a '/'.  For example 
	     * 'glob C:*cat*.exe' will return 'C:cat32.exe'
	     */
	    if (cwdStr[cwdLen-1] != '/'
		    && cwdStr[cwdLen-1] != '\\') {
		if (cwdLen != 2 || cwdStr[1] != ':') {
		    Tcl_AppendToObj(copy, "/", 1);
		    cwdLen++;
		}
	    }
	    break;
	case TCL_PLATFORM_MAC:
	    if (cwdStr[cwdLen-1] != ':') {
		Tcl_AppendToObj(copy, ":", 1);
		cwdLen++;
	    }
	    break;
    }
    Tcl_AppendObjToObj(copy, fsPathPtr->normPathPtr);
    objPtr->bytes = Tcl_GetStringFromObj(copy, &cwdLen);
    objPtr->length = cwdLen;
    copy->bytes = tclEmptyStringRep;
    copy->length = 0;
    Tcl_DecrRefCount(copy);
}

 *      as a valid file path, then NULL is returned.
/*
 *---------------------------------------------------------------------------
 *
 * TclNewFSPathObj --
 *
 *      Creates a path object whose string representation is 
 *      '[file join dirPtr addStrRep]', but does so in a way that
 *      allows for more efficient caching of normalized paths.
 *      
 * Assumptions:
 *      'dirPtr' must be an absolute path.  
 *      'len' may not be zero.
 *      
 * Results:
 *      The new Tcl object.
 *
 * Side effects:
 *	Memory is allocated.  'dirPtr' gets an additional refCount.
 *
 *---------------------------------------------------------------------------
 */

.*      NULL or a filesystem which will accept this path.
Tcl_Obj*
TclNewFSPathObj(Tcl_Obj *dirPtr, CONST char *addStrRep, int len)
{
    FsPath *fsPathPtr;
    Tcl_Obj *objPtr;
    
    objPtr = Tcl_NewObj();
    fsPathPtr = (FsPath*)ckalloc((unsigned)sizeof(FsPath));
    
    if (tclPlatform == TCL_PLATFORM_MAC) {
	/* 
	 * Mac relative paths may begin with a directory separator ':'.
	 * If present, we need to skip this ':' because we assume that
	 * we can join dirPtr and addStrRep by concatenating them as
	 * strings (and we ensure that dirPtr is terminated by a ':').
	 */
	if (addStrRep[0] == ':') {
	    addStrRep++;
	    len--;
	}
    }
    /* Setup the path */
    fsPathPtr->translatedPathPtr = NULL;
    fsPathPtr->normPathPtr = Tcl_NewStringObj(addStrRep, len);
    Tcl_IncrRefCount(fsPathPtr->normPathPtr);
    fsPathPtr->cwdPtr = dirPtr;
    Tcl_IncrRefCount(dirPtr);
    fsPathPtr->flags = TCLPATH_RELATIVE | TCLPATH_APPENDED;
    fsPathPtr->nativePathPtr = NULL;
    fsPathPtr->fsRecPtr = NULL;
    fsPathPtr->filesystemEpoch = theFilesystemEpoch;

    objPtr->internalRep.otherValuePtr = (VOID *) fsPathPtr;
    objPtr->typePtr = &tclFsPathType;
    objPtr->bytes = NULL;
    objPtr->length = 0;
    return objPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * MakeFsPathFromRelative --
 *
 *      Like SetFsPathFromAny, but assumes the given object is an
 *      absolute normalized path. Only for internal use.
 *      
 * Results:
 *      Standard Tcl error code.
 *
 * Side effects:
 *	The old representation may be freed, and new memory allocated.
 *
 *---------------------------------------------------------------------------
 */

static Tcl_Obj*
MakeFsPathFromRelative(interp, objPtr, cwdPtr)
    Tcl_Interp *interp;		/* Used for error reporting if not NULL. */
    Tcl_Obj *objPtr;		/* The object to convert. */
    Tcl_Obj *cwdPtr;		/* The object to convert. */
{
    FsPath *fsPathPtr;

    /* Free old representation */
    if (objPtr->typePtr != NULL) {
	if (objPtr->bytes == NULL) {
	    if (objPtr->typePtr->updateStringProc == NULL) {
		if (interp != NULL) {
		    Tcl_ResetResult(interp);
		    Tcl_AppendResult(interp, "can't find object",
				     "string representation", (char *) NULL);
		}
		return NULL;
	    }
	    objPtr->typePtr->updateStringProc(objPtr);
	}
	if ((objPtr->typePtr->freeIntRepProc) != NULL) {
	    (*objPtr->typePtr->freeIntRepProc)(objPtr);
	}
    }

 *
    fsPathPtr = (FsPath*)ckalloc((unsigned)sizeof(FsPath));

    /* Circular reference, by design */
    fsPathPtr->translatedPathPtr = objPtr;
    fsPathPtr->normPathPtr = NULL;
    fsPathPtr->flags = 0;
    fsPathPtr->cwdPtr = cwdPtr;
    Tcl_IncrRefCount(cwdPtr);
    fsPathPtr->nativePathPtr = NULL;
    fsPathPtr->fsRecPtr = NULL;
    fsPathPtr->filesystemEpoch = theFilesystemEpoch;

    objPtr->internalRep.otherValuePtr = (VOID *) fsPathPtr;
    objPtr->typePtr = &tclFsPathType;

    return objPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * SetFsPathFromAbsoluteNormalized --
 *
 *      Like SetFsPathFromAny, but assumes the given object is an
 *      absolute normalized path. Only for internal use.
 *      
 * Results:
 *      Standard Tcl error code.
 *
 * Side effects:
 *	The old representation may be freed, and new memory allocated.
 *
 *---------------------------------------------------------------------------
 */

 *	The object may be converted to a path type.
static int
SetFsPathFromAbsoluteNormalized(interp, objPtr)
    Tcl_Interp *interp;		/* Used for error reporting if not NULL. */
    Tcl_Obj *objPtr;		/* The object to convert. */
{
    FsPath *fsPathPtr;

 *
    if (objPtr->typePtr == &tclFsPathType) {
        return TCL_OK;
    }
    
    /* Free old representation */
    if (objPtr->typePtr != NULL) {
	if (objPtr->bytes == NULL) {
	    if (objPtr->typePtr->updateStringProc == NULL) {
		if (interp != NULL) {
		    Tcl_ResetResult(interp);
		    Tcl_AppendResult(interp, "can't find object",
				     "string representation", (char *) NULL);
		}
		return TCL_ERROR;
	    }
	    objPtr->typePtr->updateStringProc(objPtr);
	}
	if ((objPtr->typePtr->freeIntRepProc) != NULL) {
	    (*objPtr->typePtr->freeIntRepProc)(objPtr);
	}
    }

    fsPathPtr = (FsPath*)ckalloc((unsigned)sizeof(FsPath));
    /* It's a pure normalized absolute path */
    fsPathPtr->translatedPathPtr = NULL;
    fsPathPtr->normPathPtr = objPtr;
    fsPathPtr->flags = 0;
    fsPathPtr->cwdPtr = NULL;
    fsPathPtr->nativePathPtr = NULL;
    fsPathPtr->fsRecPtr = NULL;
    fsPathPtr->filesystemEpoch = theFilesystemEpoch;

    objPtr->internalRep.otherValuePtr = (VOID *) fsPathPtr;
    objPtr->typePtr = &tclFsPathType;

    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * SetFsPathFromAny --
 *
 *      This function tries to convert the given Tcl_Obj to a valid
 *      Tcl path type.
 *      
 *      The filename may begin with "~" (to indicate current user's
 *      home directory) or "~<user>" (to indicate any user's home
 *      directory).
 *
 * Results:
 *      Standard Tcl error code.
 *
 * Side effects:
 *	The old representation may be freed, and new memory allocated.
 *
 *---------------------------------------------------------------------------
 */

static int
SetFsPathFromAny(interp, objPtr)
    Tcl_Interp *interp;		/* Used for error reporting if not NULL. */
    Tcl_Obj *objPtr;		/* The object to convert. */
{
    int len;
    FsPath *fsPathPtr;
    Tcl_Obj *transPtr;
    char *name;
    
    if (objPtr->typePtr == &tclFsPathType) {
	return TCL_OK;
    }
    
    /* 
     * First step is to translate the filename.  This is similar to
     * Tcl_TranslateFilename, but shouldn't convert everything to
     * windows backslashes on that platform.  The current
     * implementation of this piece is a slightly optimised version
     * of the various Tilde/Split/Join stuff to avoid multiple
     * split/join operations.
     * 
     * We remove any trailing directory separator.
     * 
     * However, the split/join routines are quite complex, and
     * one has to make sure not to break anything on Unix, Win
     * or MacOS (fCmd.test, fileName.test and cmdAH.test exercise
     * most of the code).
     */
    name = Tcl_GetStringFromObj(objPtr,&len);

    /*
     * Handle tilde substitutions, if needed.
     */
    if (name[0] == '~') {
	char *expandedUser;
	Tcl_DString temp;
	int split;
	char separator='/';
	

	if (tclPlatform==TCL_PLATFORM_MAC) {
	    if (strchr(name, ':') != NULL) separator = ':';
	}
	
	split = FindSplitPos(name, &separator);
	if (split != len) {
	    /* We have multiple pieces '~user/foo/bar...' */
	    name[split] = '\0';
	}
	/* Do some tilde substitution */
	if (name[1] == '\0') {
	    /* We have just '~' */
	    CONST char *dir;
	    Tcl_DString dirString;
	    if (split != len) { name[split] = separator; }
	    
	    dir = TclGetEnv("HOME", &dirString);
	    if (dir == NULL) {
		if (interp) {
		    Tcl_ResetResult(interp);
		    Tcl_AppendResult(interp, "couldn't find HOME environment ",
			    "variable to expand path", (char *) NULL);
		}
		return TCL_ERROR;
	    }
	    Tcl_DStringInit(&temp);
	    Tcl_JoinPath(1, &dir, &temp);
	    Tcl_DStringFree(&dirString);
	} else {
	    /* We have a user name '~user' */
	    Tcl_DStringInit(&temp);
	    if (TclpGetUserHome(name+1, &temp) == NULL) {	
		if (interp != NULL) {
		    Tcl_ResetResult(interp);
		    Tcl_AppendResult(interp, "user \"", (name+1), 
				     "\" doesn't exist", (char *) NULL);
		}
		Tcl_DStringFree(&temp);
		if (split != len) { name[split] = separator; }
		return TCL_ERROR;
	    }
	    if (split != len) { name[split] = separator; }
	}
	
	expandedUser = Tcl_DStringValue(&temp);
	transPtr = Tcl_NewStringObj(expandedUser, Tcl_DStringLength(&temp));

	if (split != len) {
	    /* Join up the tilde substitution with the rest */
	    if (name[split+1] == separator) {

		/*
		 * Somewhat tricky case like ~//foo/bar.
		 * Make use of Split/Join machinery to get it right.
		 * Assumes all paths beginning with ~ are part of the
		 * native filesystem.
Tcl_Filesystem*
		 */

Tcl_FSGetFileSystemForPath(pathObjPtr)
		int objc;
		Tcl_Obj **objv;
		Tcl_Obj *parts = TclpNativeSplitPath(objPtr, NULL);
		Tcl_ListObjGetElements(NULL, parts, &objc, &objv);
		/* Skip '~'.  It's replaced by its expansion */
		objc--; objv++;
		while (objc--) {
		    TclpNativeJoinPath(transPtr, Tcl_GetString(*objv++));
		}
		Tcl_DecrRefCount(parts);
	    } else {
		/* Simple case. "rest" is relative path.  Just join it. */
		Tcl_Obj *rest = Tcl_NewStringObj(name+split+1,-1);
		transPtr = Tcl_FSJoinToPath(transPtr, 1, &rest);
	    }
	}
	Tcl_DStringFree(&temp);
    } else {
	transPtr = Tcl_FSJoinToPath(objPtr,0,NULL);
    }

    /* 
     * Now we have a translated filename in 'transPtr'.  This will have
     * forward slashes on Windows, and will not contain any ~user
     * sequences.
     */
    
    fsPathPtr = (FsPath*)ckalloc((unsigned)sizeof(FsPath));
    fsPathPtr->translatedPathPtr = transPtr;
    Tcl_IncrRefCount(fsPathPtr->translatedPathPtr);
    fsPathPtr->normPathPtr = NULL;
    fsPathPtr->flags = 0;
    fsPathPtr->cwdPtr = NULL;
    fsPathPtr->nativePathPtr = NULL;
    fsPathPtr->fsRecPtr = NULL;
    fsPathPtr->filesystemEpoch = theFilesystemEpoch;

    /*
     * Free old representation before installing our new one.
     */
    if (objPtr->typePtr != NULL && objPtr->typePtr->freeIntRepProc != NULL) {
	(objPtr->typePtr->freeIntRepProc)(objPtr);
    }
    objPtr->internalRep.otherValuePtr = (VOID *) fsPathPtr;
    objPtr->typePtr = &tclFsPathType;

    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSNewNativePath --
 *
 *      This function performs the something like that reverse of the 
 *      usual obj->path->nativerep conversions.  If some code retrieves
 *      a path in native form (from, e.g. readlink or a native dialog),
 *      and that path is to be used at the Tcl level, then calling
 *      this function is an efficient way of creating the appropriate
 *      path object type.
 *      
 *      Any memory which is allocated for 'clientData' should be retained
 *      until clientData is passed to the filesystem's freeInternalRepProc
 *      when it can be freed.  The built in platform-specific filesystems
 *      use 'ckalloc' to allocate clientData, and ckfree to free it.
 *
 * Results:
 *      NULL or a valid path object pointer, with refCount zero.
 *
 * Side effects:
 *	New memory may be allocated.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
    Tcl_Obj* pathObjPtr;
Tcl_FSNewNativePath(fromFilesystem, clientData)
    Tcl_Filesystem* fromFilesystem;
    ClientData clientData;
{
    Tcl_Obj *objPtr;
    FsPath *fsPathPtr;
    FilesystemRecord *fsFromPtr;
    FilesystemRecord *fsRecPtr;
    Tcl_FSInternalToNormalizedProc *proc;
    int epoch;
    
    Tcl_Filesystem* retVal = NULL;
    fsFromPtr = GetFilesystemRecord(fromFilesystem, &epoch);

    if (fsFromPtr == NULL) {
	return NULL;
    }
    
    proc = fsFromPtr->fsPtr->internalToNormalizedProc;

    if (proc == NULL) {
        return NULL;
    }
    
    objPtr = (*proc)(clientData);
    if (objPtr == NULL) {
        return NULL;
    }
    
    /* 
     * Free old representation; shouldn't normally be any,
     * but best to be safe. 
     */
    if (objPtr->typePtr != NULL) {
	if (objPtr->bytes == NULL) {
	    if (objPtr->typePtr->updateStringProc == NULL) {
		return NULL;
	    }
	    objPtr->typePtr->updateStringProc(objPtr);
	}
	if ((objPtr->typePtr->freeIntRepProc) != NULL) {
	    (*objPtr->typePtr->freeIntRepProc)(objPtr);
	}
    }
    
    fsPathPtr = (FsPath*)ckalloc((unsigned)sizeof(FsPath));
    fsPathPtr->translatedPathPtr = NULL;
    /* Circular reference, by design */
    fsPathPtr->normPathPtr = objPtr;
    fsPathPtr->flags = 0;
    fsPathPtr->cwdPtr = NULL;
    fsPathPtr->nativePathPtr = clientData;
    fsPathPtr->fsRecPtr = fsFromPtr;
    /* We must increase the refCount for this filesystem. */
    fsPathPtr->fsRecPtr->fileRefCount++;
    fsPathPtr->filesystemEpoch = epoch;

    objPtr->internalRep.otherValuePtr = (VOID *) fsPathPtr;
    objPtr->typePtr = &tclFsPathType;
    return objPtr;
}

static void
FreeFsPathInternalRep(pathObjPtr)
    Tcl_Obj *pathObjPtr;	/* Path object with internal rep to free. */
{
    register FsPath* fsPathPtr = 
      (FsPath*) pathObjPtr->internalRep.otherValuePtr;

    if (fsPathPtr->translatedPathPtr != NULL) {
	if (fsPathPtr->translatedPathPtr != pathObjPtr) {
	    Tcl_DecrRefCount(fsPathPtr->translatedPathPtr);
	}
    }
    if (fsPathPtr->normPathPtr != NULL) {
	if (fsPathPtr->normPathPtr != pathObjPtr) {
	    Tcl_DecrRefCount(fsPathPtr->normPathPtr);
	}
	fsPathPtr->normPathPtr = NULL;
    }
    
    if (fsPathPtr->cwdPtr != NULL) {
	Tcl_DecrRefCount(fsPathPtr->cwdPtr);
    }
    if (fsPathPtr->nativePathPtr != NULL) {
	if (fsPathPtr->fsRecPtr != NULL) {
	    if (fsPathPtr->fsRecPtr->fsPtr->freeInternalRepProc != NULL) {
		(*fsPathPtr->fsRecPtr->fsPtr
		   ->freeInternalRepProc)(fsPathPtr->nativePathPtr);
		fsPathPtr->nativePathPtr = NULL;
	    }
	}
    }
    if (fsPathPtr->fsRecPtr != NULL) {
        fsPathPtr->fsRecPtr->fileRefCount--;
	if (fsPathPtr->fsRecPtr->fileRefCount <= 0) {
	    /* It has been unregistered already */
	    ckfree((char *)fsPathPtr->fsRecPtr);
	}
    }

    /* 
    ckfree((char*) fsPathPtr);
}

     * If the object has a refCount of zero, we reject it.  This
static void
DupFsPathInternalRep(srcPtr, copyPtr)
    Tcl_Obj *srcPtr;		/* Path obj with internal rep to copy. */
    Tcl_Obj *copyPtr;		/* Path obj with internal rep to set. */
{
    register FsPath* srcFsPathPtr = 
      (FsPath*) srcPtr->internalRep.otherValuePtr;
    register FsPath* copyFsPathPtr = 
      (FsPath*) ckalloc((unsigned)sizeof(FsPath));
    Tcl_FSDupInternalRepProc *dupProc;
    
     * is to avoid possible segfaults or nondeterministic memory
    copyPtr->internalRep.otherValuePtr = (VOID *) copyFsPathPtr;

     * leaks (i.e. the user doesn't know if they should decrement
    if (srcFsPathPtr->translatedPathPtr != NULL) {
	copyFsPathPtr->translatedPathPtr = srcFsPathPtr->translatedPathPtr;
	if (copyFsPathPtr->translatedPathPtr != copyPtr) {
	    Tcl_IncrRefCount(copyFsPathPtr->translatedPathPtr);
	}
    } else {
	copyFsPathPtr->translatedPathPtr = NULL;
    }
    
     * the ref count on return or not).
    if (srcFsPathPtr->normPathPtr != NULL) {
	copyFsPathPtr->normPathPtr = srcFsPathPtr->normPathPtr;
	if (copyFsPathPtr->normPathPtr != copyPtr) {
	    Tcl_IncrRefCount(copyFsPathPtr->normPathPtr);
	}
    } else {
	copyFsPathPtr->normPathPtr = NULL;
    }
    
     */
    if (srcFsPathPtr->cwdPtr != NULL) {
	copyFsPathPtr->cwdPtr = srcFsPathPtr->cwdPtr;
	Tcl_IncrRefCount(copyFsPathPtr->cwdPtr);
    } else {
	copyFsPathPtr->cwdPtr = NULL;
    }

    copyFsPathPtr->flags = srcFsPathPtr->flags;
    
    if (srcFsPathPtr->fsRecPtr != NULL 
      && srcFsPathPtr->nativePathPtr != NULL) {
	dupProc = srcFsPathPtr->fsRecPtr->fsPtr->dupInternalRepProc;
	if (dupProc != NULL) {
	    copyFsPathPtr->nativePathPtr = 
	      (*dupProc)(srcFsPathPtr->nativePathPtr);
	} else {
	    copyFsPathPtr->nativePathPtr = NULL;
	}
    
    } else {
	copyFsPathPtr->nativePathPtr = NULL;
    }
    copyFsPathPtr->fsRecPtr = srcFsPathPtr->fsRecPtr;
    copyFsPathPtr->filesystemEpoch = srcFsPathPtr->filesystemEpoch;
    if (copyFsPathPtr->fsRecPtr != NULL) {
        copyFsPathPtr->fsRecPtr->fileRefCount++;
    }

    if (pathObjPtr->refCount == 0) {
    copyPtr->typePtr = &tclFsPathType;
}

	panic("Tcl_FSGetFileSystemForPath called with object with refCount == 0");
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSGetTranslatedPath --
 *
 *      This function attempts to extract the translated path
 *      from the given Tcl_Obj.  If the translation succeeds (i.e. the
 *      object is a valid path), then it is returned.  Otherwise NULL
 *      will be returned, and an error message may be left in the
 *      interpreter (if it is non-NULL)
 *
 * Results:
 *      NULL or a valid Tcl_Obj pointer.
 *
 * Side effects:
 *	Only those of 'Tcl_FSConvertToPathType'
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj* 
Tcl_FSGetTranslatedPath(interp, pathPtr)
    Tcl_Interp *interp;
    Tcl_Obj* pathPtr;
{
    register FsPath* srcFsPathPtr;
    if (Tcl_FSConvertToPathType(interp, pathPtr) != TCL_OK) {
	return NULL;
    }
    srcFsPathPtr = (FsPath*) pathPtr->internalRep.otherValuePtr;
    if (srcFsPathPtr->translatedPathPtr == NULL) {
        if (srcFsPathPtr->flags != 0) {
	    return Tcl_FSGetNormalizedPath(interp, pathPtr);
        }
        /* 
         * It is a pure absolute, normalized path object.
         * This is something like being a 'pure list'.  The
         * object's string, translatedPath and normalizedPath
         * are all identical.
         */
	return srcFsPathPtr->normPathPtr;
    } else {
	/* It is an ordinary path object */
	return srcFsPathPtr->translatedPathPtr;
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSGetTranslatedStringPath --
 *
 *      This function attempts to extract the translated path
 *      from the given Tcl_Obj.  If the translation succeeds (i.e. the
 *      object is a valid path), then the path is returned.  Otherwise NULL
 *      will be returned, and an error message may be left in the
 *      interpreter (if it is non-NULL)
 *
    
 * Results:
 *      NULL or a valid string.
 *
 * Side effects:
 *	Only those of 'Tcl_FSConvertToPathType'
 *
 *---------------------------------------------------------------------------
 */
CONST char*
Tcl_FSGetTranslatedStringPath(interp, pathPtr)
    Tcl_Interp *interp;
    Tcl_Obj* pathPtr;
{
    Tcl_Obj *transPtr = Tcl_FSGetTranslatedPath(interp, pathPtr);
    if (transPtr == NULL) {
        return NULL;
    } else {
	return Tcl_GetString(transPtr);
    }
}

/*
    /* 
 *---------------------------------------------------------------------------
 *
 * Tcl_FSGetNormalizedPath --
 *
 *      This important function attempts to extract from the given Tcl_Obj
 *      a unique normalised path representation, whose string value can
 *      be used as a unique identifier for the file.
 *
 * Results:
 *      NULL or a valid path object pointer.
 *
 * Side effects:
 *	New memory may be allocated.  The Tcl 'errno' may be modified
 *      in the process of trying to examine various path possibilities.
 *
 *---------------------------------------------------------------------------
 */

     * Check if the filesystem has changed in some way since
Tcl_Obj* 
Tcl_FSGetNormalizedPath(interp, pathObjPtr)
    Tcl_Interp *interp;
    Tcl_Obj* pathObjPtr;
{
    register FsPath* fsPathPtr;
    if (Tcl_FSConvertToPathType(interp, pathObjPtr) != TCL_OK) {
	return NULL;
    }
    fsPathPtr = (FsPath*) pathObjPtr->internalRep.otherValuePtr;

     * this object's internal representation was calculated.
    if (fsPathPtr->flags != 0) {
	/* 
	 * This is a special path object which is the result of
	 * something like 'file join' 
	 */
     */
	Tcl_Obj *dir, *copy;
	int cwdLen;
	int pathType;
    if (TclFSEnsureEpochOk(pathObjPtr, theFilesystemEpoch, 
	CONST char *cwdStr;
	
			   &retVal) != TCL_OK) {
	pathType = Tcl_FSGetPathType(fsPathPtr->cwdPtr);
	dir = Tcl_FSGetNormalizedPath(interp, fsPathPtr->cwdPtr);
	if (dir == NULL) {
	    return NULL;
	}
	return NULL;
    }
	if (pathObjPtr->bytes == NULL) {
	    UpdateStringOfFsPath(pathObjPtr);
	}

	copy = Tcl_DuplicateObj(dir);
	Tcl_IncrRefCount(copy);
	Tcl_IncrRefCount(dir);
	/* We now own a reference on both 'dir' and 'copy' */
	
	cwdStr = Tcl_GetStringFromObj(copy, &cwdLen);
	/* 
    /*
	 * Should we perhaps use 'Tcl_FSPathSeparator'?
	 * But then what about the Windows special case?
	 * Perhaps we should just check if cwd is a root volume.
	 * We should never get cwdLen == 0 in this code path.
	 */
	switch (tclPlatform) {
	    case TCL_PLATFORM_UNIX:
		if (cwdStr[cwdLen-1] != '/') {
		    Tcl_AppendToObj(copy, "/", 1);
		    cwdLen++;
		}
		break;
	    case TCL_PLATFORM_WINDOWS:
		if (cwdStr[cwdLen-1] != '/' 
			&& cwdStr[cwdLen-1] != '\\') {
		    Tcl_AppendToObj(copy, "/", 1);
		    cwdLen++;
		}
		break;
	    case TCL_PLATFORM_MAC:
		if (cwdStr[cwdLen-1] != ':') {
		    Tcl_AppendToObj(copy, ":", 1);
		    cwdLen++;
		}
		break;
	}
	Tcl_AppendObjToObj(copy, fsPathPtr->normPathPtr);
	/* 
	 * Normalize the combined string, but only starting after
	 * the end of the previously normalized 'dir'.  This should
     * Call each of the "pathInFilesystem" functions in succession.  A
	 * be much faster!  We use 'cwdLen-1' so that we are
         * already pointing at the dir-separator that we know about.
         * The normalization code will actually start off directly
         * after that separator.
	 */
     * non-return value of -1 indicates the particular function has
     * succeeded.
     */
	TclNormalizeToUniquePath(interp, copy, cwdLen-1);
	/* Now we need to construct the new path object */
	

	if (pathType == TCL_PATH_RELATIVE) {
	    register FsPath* origDirFsPathPtr;
	    Tcl_Obj *origDir = fsPathPtr->cwdPtr;
	    origDirFsPathPtr = (FsPath*) origDir->internalRep.otherValuePtr;
	    
    fsRecPtr = FsGetIterator();
    while ((retVal == NULL) && (fsRecPtr != NULL)) {
	    fsPathPtr->cwdPtr = origDirFsPathPtr->cwdPtr;
	    Tcl_IncrRefCount(fsPathPtr->cwdPtr);
	    
	Tcl_FSPathInFilesystemProc *proc = fsRecPtr->fsPtr->pathInFilesystemProc;
	    Tcl_DecrRefCount(fsPathPtr->normPathPtr);
	    fsPathPtr->normPathPtr = copy;
	    /* That's our reference to copy used */
	    Tcl_DecrRefCount(dir);
	    Tcl_DecrRefCount(origDir);
	} else {
	    Tcl_DecrRefCount(fsPathPtr->cwdPtr);
	    fsPathPtr->cwdPtr = NULL;
	    Tcl_DecrRefCount(fsPathPtr->normPathPtr);
	    fsPathPtr->normPathPtr = copy;
	    /* That's our reference to copy used */
	    Tcl_DecrRefCount(dir);
	}
	fsPathPtr->flags = 0;
    }
    /* Ensure cwd hasn't changed */
    if (fsPathPtr->cwdPtr != NULL) {
	if (proc != NULL) {
	if (!FsCwdPointerEquals(fsPathPtr->cwdPtr)) {
	    if (pathObjPtr->bytes == NULL) {
		UpdateStringOfFsPath(pathObjPtr);
	    }
	    FreeFsPathInternalRep(pathObjPtr);
	    pathObjPtr->typePtr = NULL;
	    if (Tcl_ConvertToType(interp, pathObjPtr, 
				  &tclFsPathType) != TCL_OK) {
	        return NULL;
	    ClientData clientData = NULL;
	    }
	    fsPathPtr = (FsPath*) pathObjPtr->internalRep.otherValuePtr;
	} else if (fsPathPtr->normPathPtr == NULL) {
	    int cwdLen;
	    Tcl_Obj *copy;
	    CONST char *cwdStr;
	    
	    int ret = (*proc)(pathObjPtr, &clientData);
	    copy = Tcl_DuplicateObj(fsPathPtr->cwdPtr);
	    Tcl_IncrRefCount(copy);
	    cwdStr = Tcl_GetStringFromObj(copy, &cwdLen);
	    /* 
	     * Should we perhaps use 'Tcl_FSPathSeparator'?
	     * But then what about the Windows special case?
	     * Perhaps we should just check if cwd is a root volume.
	     * We should never get cwdLen == 0 in this code path.
	     */
	    switch (tclPlatform) {
		case TCL_PLATFORM_UNIX:
		    if (cwdStr[cwdLen-1] != '/') {
			Tcl_AppendToObj(copy, "/", 1);
			cwdLen++;
		    }
		    break;
		case TCL_PLATFORM_WINDOWS:
		    if (cwdStr[cwdLen-1] != '/' 
	    if (ret != -1) {
			    && cwdStr[cwdLen-1] != '\\') {
			Tcl_AppendToObj(copy, "/", 1);
			cwdLen++;
		    }
		    break;
		case TCL_PLATFORM_MAC:
		    if (cwdStr[cwdLen-1] != ':') {
			Tcl_AppendToObj(copy, ":", 1);
			cwdLen++;
		    }
		    break;
	    }
	    Tcl_AppendObjToObj(copy, pathObjPtr);
	    /* 
		/* 
	     * Normalize the combined string, but only starting after
	     * the end of the previously normalized 'dir'.  This should
	     * be much faster!
	     */
	    TclNormalizeToUniquePath(interp, copy, cwdLen-1);
	    fsPathPtr->normPathPtr = copy;
	}
    }
    if (fsPathPtr->normPathPtr == NULL) {
	int relative = 0;
	/* 
	 * Since normPathPtr is NULL, but this is a valid path
	 * object, we know that the translatedPathPtr cannot be NULL.
	 */
	Tcl_Obj *absolutePath = fsPathPtr->translatedPathPtr;
	char *path = Tcl_GetString(absolutePath);
	
		 * We assume the type of pathObjPtr hasn't been changed 
	/* 
	 * We have to be a little bit careful here to avoid infinite loops
	 * we're asking Tcl_FSGetPathType to return the path's type, but
	 * that call can actually result in a lot of other filesystem
		 * by the above call to the pathInFilesystemProc.
	 * action, which might loop back through here.
	 */
		 */
	if ((path[0] != '\0') && 
	  (Tcl_FSGetPathType(pathObjPtr) == TCL_PATH_RELATIVE)) {
	    Tcl_Obj *cwd = Tcl_FSGetCwd(interp);

		TclFSSetPathDetails(pathObjPtr, fsRecPtr, clientData, 
	    if (cwd == NULL) {
		return NULL;
	    }

			       theFilesystemEpoch);
	    absolutePath = Tcl_FSJoinToPath(cwd, 1, &absolutePath);
	    Tcl_IncrRefCount(absolutePath);
	    Tcl_DecrRefCount(cwd);
	    
		retVal = fsRecPtr->fsPtr;
	    relative = 1;
	}
	    }
	/* Already has refCount incremented */
	fsPathPtr->normPathPtr = FSNormalizeAbsolutePath(interp, absolutePath);
	if (!strcmp(Tcl_GetString(fsPathPtr->normPathPtr),
		    Tcl_GetString(pathObjPtr))) {
	    /* 
	     * The path was already normalized.  
	     * Get rid of the duplicate.
	     */
	    Tcl_DecrRefCount(fsPathPtr->normPathPtr);
	    /* 
	     * We do *not* increment the refCount for 
	     * this circular reference 
	     */
	    fsPathPtr->normPathPtr = pathObjPtr;
	}
	if (relative) {
	    /* This was returned by Tcl_FSJoinToPath above */
	    Tcl_DecrRefCount(absolutePath);

	fsRecPtr = fsRecPtr->nextPtr;
	    /* Get a quick, temporary lock on the cwd while we copy it */
	    Tcl_MutexLock(&cwdMutex);
	    fsPathPtr->cwdPtr = cwdPathPtr;
	    Tcl_IncrRefCount(fsPathPtr->cwdPtr);
	    Tcl_MutexUnlock(&cwdMutex);
	}
    }
    }
    return fsPathPtr->normPathPtr;
}

    FsReleaseIterator();
/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSGetInternalRep --
 *
 *      Extract the internal representation of a given path object,
 *      in the given filesystem.  If the path object belongs to a
 *      different filesystem, we return NULL.
 *      
 *      If the internal representation is currently NULL, we attempt
 *      to generate it, by calling the filesystem's 
 *      'Tcl_FSCreateInternalRepProc'.
 *
 * Results:
 *      NULL or a valid internal representation.
 *
 * Side effects:
 *	An attempt may be made to convert the object.
 *
 *---------------------------------------------------------------------------
 */

ClientData 
Tcl_FSGetInternalRep(pathObjPtr, fsPtr)
    Tcl_Obj* pathObjPtr;
    Tcl_Filesystem *fsPtr;
{
    register FsPath* srcFsPathPtr;
    

    if (Tcl_FSConvertToPathType(NULL, pathObjPtr) != TCL_OK) {
	return NULL;
    return retVal;
    }
    srcFsPathPtr = (FsPath*) pathObjPtr->internalRep.otherValuePtr;
    
    /* 
     * We will only return the native representation for the caller's
     * filesystem.  Otherwise we will simply return NULL. This means
     * that there must be a unique bi-directional mapping between paths
     * and filesystems, and that this mapping will not allow 'remapped'
     * files -- files which are in one filesystem but mapped into
     * another.  Another way of putting this is that 'stacked'
     * filesystems are not allowed.  We recognise that this is a
     * potentially useful feature for the future.
     * 
     * Even something simple like a 'pass through' filesystem which
     * logs all activity and passes the calls onto the native system
     * would be nice, but not easily achievable with the current
     * implementation.
     */
    if (srcFsPathPtr->fsRecPtr == NULL) {
	/* 
	 * This only usually happens in wrappers like TclpStat which
	 * create a string object and pass it to TclpObjStat.  Code
	 * which calls the Tcl_FS..  functions should always have a
	 * filesystem already set.  Whether this code path is legal or
	 * not depends on whether we decide to allow external code to
	 * call the native filesystem directly.  It is at least safer
	 * to allow this sub-optimal routing.
	 */
	Tcl_FSGetFileSystemForPath(pathObjPtr);
	
	/* 
	 * If we fail through here, then the path is probably not a
	 * valid path in the filesystsem, and is most likely to be a
	 * use of the empty path "" via a direct call to one of the
	 * objectified interfaces (e.g. from the Tcl testsuite).
	 */
	srcFsPathPtr = (FsPath*) pathObjPtr->internalRep.otherValuePtr;
	if (srcFsPathPtr->fsRecPtr == NULL) {
	    return NULL;
	}
    }

    if (fsPtr != srcFsPathPtr->fsRecPtr->fsPtr) {
	/* 
	 * There is still one possibility we should consider; if the
	 * file belongs to a different filesystem, perhaps it is
	 * actually linked through to a file in our own filesystem
	 * which we do care about.  The way we can check for this
	 * is we ask what filesystem this path belongs to.
	 */
	Tcl_Filesystem *actualFs = Tcl_FSGetFileSystemForPath(pathObjPtr);
	if (actualFs == fsPtr) {
	    return Tcl_FSGetInternalRep(pathObjPtr, fsPtr);
	}
	return NULL;
    }

    if (srcFsPathPtr->nativePathPtr == NULL) {
	Tcl_FSCreateInternalRepProc *proc;
	proc = srcFsPathPtr->fsRecPtr->fsPtr->createInternalRepProc;

	if (proc == NULL) {
	    return NULL;
	}
	srcFsPathPtr->nativePathPtr = (*proc)(pathObjPtr);
    }
    return srcFsPathPtr->nativePathPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSGetNativePath --
 *

 *      to copy the representation.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */
static ClientData 
ClientData 
NativeDupInternalRep(clientData)
    ClientData clientData;
{
    ClientData copy;
    size_t len;

    if (clientData == NULL) {

    len = sizeof(char) + (strlen((CONST char*)clientData) * sizeof(char));
#endif
    
    copy = (ClientData) ckalloc(len);
    memcpy((VOID*)copy, (VOID*)clientData, len);
    return copy;
}

/*
 *---------------------------------------------------------------------------
 *
 * NativePathInFilesystem --
 *
 *      Any path object is acceptable to the native filesystem, by
 *      default (we will throw errors when illegal paths are actually
 *      tried to be used).
 *      
 *      However, this behavior means the native filesystem must be
 *      the last filesystem in the lookup list (otherwise it will
 *      claim all files belong to it, and other filesystems will
 *      never get a look in).
 *
 * Results:
 *      TCL_OK, to indicate 'yes', -1 to indicate no.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */
static int 
NativePathInFilesystem(pathPtr, clientDataPtr)
    Tcl_Obj *pathPtr;
    ClientData *clientDataPtr;
{
    int len;
    Tcl_GetStringFromObj(pathPtr,&len);
    if (len == 0) {
        return -1;
    } else {
	/* We accept any path as valid */
	return TCL_OK;
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * NativeFreeInternalRep --
 *
 *      Free a native internal representation, which will be non-NULL.

	    break;
	case TCL_PLATFORM_MAC:
	    separator = ":";
	    break;
    }
    return Tcl_NewStringObj(separator,1);
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSGetFileSystemForPath --
 *
 *      This function determines which filesystem to use for a
 *      particular path object, and returns the filesystem which
 *      accepts this file.  If no filesystem will accept this object
 *      as a valid file path, then NULL is returned.
 *
 * Results:
.*      NULL or a filesystem which will accept this path.
 *
 * Side effects:
 *	The object may be converted to a path type.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Filesystem*
Tcl_FSGetFileSystemForPath(pathObjPtr)
    Tcl_Obj* pathObjPtr;
{
    FilesystemRecord *fsRecPtr;
    Tcl_Filesystem* retVal = NULL;
    FsPath* srcFsPathPtr;
    
    /* 
     * If the object has a refCount of zero, we reject it.  This
     * is to avoid possible segfaults or nondeterministic memory
     * leaks (i.e. the user doesn't know if they should decrement
     * the ref count on return or not).
     */
    
    if (pathObjPtr->refCount == 0) {
	panic("Tcl_FSGetFileSystemForPath called with object with refCount == 0");
        return NULL;
    }
    
    /* 
     * This will ensure the pathObjPtr can be converted into a 
     * "path" type, and that we are able to generate a complete
     * normalized path which is used to determine the filesystem
     * match.
     */

    if (Tcl_FSGetNormalizedPath(NULL, pathObjPtr) == NULL) {
	return NULL;
    }
    
    /* 
     * Get a lock on theFilesystemEpoch and the filesystemList
     * 
     * While we don't need the fsRecPtr until the while loop below, we
     * do want to make sure the theFilesystemEpoch doesn't change
     * between the 'if' and 'while' blocks, getting this iterator will
     * ensure that everything is consistent
     */
    fsRecPtr = FsGetIterator();
    
    /* Make sure pathObjPtr is of the correct epoch */
    
    srcFsPathPtr = (FsPath*) pathObjPtr->internalRep.otherValuePtr;
    
    /* 
     * Check if the filesystem has changed in some way since
     * this object's internal representation was calculated.
     */
    if (srcFsPathPtr->filesystemEpoch != theFilesystemEpoch) {
	/* 
	 * We have to discard the stale representation and 
	 * recalculate it 
	 */
	if (pathObjPtr->bytes == NULL) {
	    UpdateStringOfFsPath(pathObjPtr);
	}
	FreeFsPathInternalRep(pathObjPtr);
	pathObjPtr->typePtr = NULL;
	if (SetFsPathFromAny(NULL, pathObjPtr) != TCL_OK) {
	    goto done;
	}
	srcFsPathPtr = (FsPath*) pathObjPtr->internalRep.otherValuePtr;
    }
    
    /* Check whether the object is already assigned to a fs */
    if (srcFsPathPtr->fsRecPtr != NULL) {
        retVal = srcFsPathPtr->fsRecPtr->fsPtr;
        goto done;
    }
    
    /*
     * Call each of the "pathInFilesystem" functions in succession.  A
     * non-return value of -1 indicates the particular function has
     * succeeded.
     */

    while ((retVal == NULL) && (fsRecPtr != NULL)) {
	Tcl_FSPathInFilesystemProc *proc = fsRecPtr->fsPtr->pathInFilesystemProc;
	if (proc != NULL) {
	    ClientData clientData = NULL;
	    int ret = (*proc)(pathObjPtr, &clientData);
	    if (ret != -1) {
		/* 
		 * We assume the srcFsPathPtr hasn't been changed 
		 * by the above call to the pathInFilesystemProc.
		 */
		srcFsPathPtr->fsRecPtr = fsRecPtr;
		srcFsPathPtr->nativePathPtr = clientData;
		srcFsPathPtr->filesystemEpoch = theFilesystemEpoch;
		fsRecPtr->fileRefCount++;
		retVal = fsRecPtr->fsPtr;
	    }
	}
	fsRecPtr = fsRecPtr->nextPtr;
    }

  done:
    FsReleaseIterator();
    return retVal;
}

/* Simple helper function */
static FilesystemRecord* 
GetFilesystemRecord(fromFilesystem, epoch)
    Tcl_Filesystem *fromFilesystem;
    int *epoch;
{
    FilesystemRecord *fsRecPtr = FsGetIterator();
    while (fsRecPtr != NULL) {
	if (fsRecPtr->fsPtr == fromFilesystem) {
	    *epoch = theFilesystemEpoch;
	    break;
	}
	fsRecPtr = fsRecPtr->nextPtr;
    }
    FsReleaseIterator();
    return fsRecPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSEqualPaths --
 *
 *      This function tests whether the two paths given are equal path
 *      objects.  If either or both is NULL, 0 is always returned.
 *
 * Results:
 *      1 or 0.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

int 
Tcl_FSEqualPaths(firstPtr, secondPtr)
    Tcl_Obj* firstPtr;
    Tcl_Obj* secondPtr;
{
    if (firstPtr == secondPtr) {
        return 1;
    } else {
	char *firstStr, *secondStr;
        int firstLen, secondLen, tempErrno;

	if (firstPtr == NULL || secondPtr == NULL) {
	    return 0;
	}
	firstStr  = Tcl_GetStringFromObj(firstPtr, &firstLen);
	secondStr = Tcl_GetStringFromObj(secondPtr, &secondLen);
	if ((firstLen == secondLen) && (strcmp(firstStr, secondStr) == 0)) {
	    return 1;
	}
	/* 
         * Try the most thorough, correct method of comparing fully
         * normalized paths
         */

	tempErrno = Tcl_GetErrno();
	firstPtr = Tcl_FSGetNormalizedPath(NULL, firstPtr);
	secondPtr = Tcl_FSGetNormalizedPath(NULL, secondPtr);
	Tcl_SetErrno(tempErrno);

	if (firstPtr == NULL || secondPtr == NULL) {
	    return 0;
	}
	firstStr  = Tcl_GetStringFromObj(firstPtr, &firstLen);
	secondStr = Tcl_GetStringFromObj(secondPtr, &secondLen);
	if ((firstLen == secondLen) && (strcmp(firstStr, secondStr) == 0)) {
	    return 1;
	}
    }
    return 0;
}

/* Everything from here on is contained in this obsolete ifdef */
#ifdef USE_OBSOLETE_FS_HOOKS

/*
 *----------------------------------------------------------------------
 *