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#!/usr/bin/env python3
#
# multibytecodec_support.py
#   Common Unittest Routines for CJK codecs
#

import codecs
import os
import re
import sys
import unittest
from http.client import HTTPException
from test import support
from io import BytesIO

class TestBase:
    encoding        = ''   # codec name
    codec           = None # codec tuple (with 4 elements)
    tstring         = None # must set. 2 strings to test StreamReader

    codectests      = None # must set. codec test tuple
    roundtriptest   = 1    # set if roundtrip is possible with unicode
    has_iso10646    = 0    # set if this encoding contains whole iso10646 map
    xmlcharnametest = None # string to test xmlcharrefreplace
    unmappedunicode = '\udeee' # a unicode codepoint that is not mapped.

    def setUp(self):
        if self.codec is None:
            self.codec = codecs.lookup(self.encoding)
        self.encode = self.codec.encode
        self.decode = self.codec.decode
        self.reader = self.codec.streamreader
        self.writer = self.codec.streamwriter
        self.incrementalencoder = self.codec.incrementalencoder
        self.incrementaldecoder = self.codec.incrementaldecoder

    def test_chunkcoding(self):
        tstring_lines = []
        for b in self.tstring:
            lines = b.split(b"\n")
            last = lines.pop()
            assert last == b""
            lines = [line + b"\n" for line in lines]
            tstring_lines.append(lines)
        for native, utf8 in zip(*tstring_lines):
            u = self.decode(native)[0]
            self.assertEqual(u, utf8.decode('utf-8'))
            if self.roundtriptest:
                self.assertEqual(native, self.encode(u)[0])

    def test_errorhandle(self):
        for source, scheme, expected in self.codectests:
            if isinstance(source, bytes):
                func = self.decode
            else:
                func = self.encode
            if expected:
                result = func(source, scheme)[0]
                if func is self.decode:
                    self.assertTrue(type(result) is str, type(result))
                    self.assertEqual(result, expected,
                                     '%a.decode(%r, %r)=%a != %a'
                                     % (source, self.encoding, scheme, result,
                                        expected))
                else:
                    self.assertTrue(type(result) is bytes, type(result))
                    self.assertEqual(result, expected,
                                     '%a.encode(%r, %r)=%a != %a'
                                     % (source, self.encoding, scheme, result,
                                        expected))
            else:
                self.assertRaises(UnicodeError, func, source, scheme)

    def test_xmlcharrefreplace(self):
        if self.has_iso10646:
            return

        s = "\u0b13\u0b23\u0b60 nd eggs"
        self.assertEqual(
            self.encode(s, "xmlcharrefreplace")[0],
            b"ଓଣୠ nd eggs"
        )

    def test_customreplace_encode(self):
        if self.has_iso10646:
            return

        from html.entities import codepoint2name

        def xmlcharnamereplace(exc):
            if not isinstance(exc, UnicodeEncodeError):
                raise TypeError("don't know how to handle %r" % exc)
            l = []
            for c in exc.object[exc.start:exc.end]:
                if ord(c) in codepoint2name:
                    l.append("&%s;" % codepoint2name[ord(c)])
                else:
                    l.append("&#%d;" % ord(c))
            return ("".join(l), exc.end)

        codecs.register_error("test.xmlcharnamereplace", xmlcharnamereplace)

        if self.xmlcharnametest:
            sin, sout = self.xmlcharnametest
        else:
            sin = "\xab\u211c\xbb = \u2329\u1234\u232a"
            sout = b"«ℜ» = ⟨ሴ⟩"
        self.assertEqual(self.encode(sin,
                                    "test.xmlcharnamereplace")[0], sout)

    def test_callback_returns_bytes(self):
        def myreplace(exc):
            return (b"1234", exc.end)
        codecs.register_error("test.cjktest", myreplace)
        enc = self.encode("abc" + self.unmappedunicode + "def", "test.cjktest")[0]
        self.assertEqual(enc, b"abc1234def")

    def test_callback_wrong_objects(self):
        def myreplace(exc):
            return (ret, exc.end)
        codecs.register_error("test.cjktest", myreplace)

        for ret in ([1, 2, 3], [], None, object()):
            self.assertRaises(TypeError, self.encode, self.unmappedunicode,
                              'test.cjktest')

    def test_callback_long_index(self):
        def myreplace(exc):
            return ('x', int(exc.end))
        codecs.register_error("test.cjktest", myreplace)
        self.assertEqual(self.encode('abcd' + self.unmappedunicode + 'efgh',
                                     'test.cjktest'), (b'abcdxefgh', 9))

        def myreplace(exc):
            return ('x', sys.maxsize + 1)
        codecs.register_error("test.cjktest", myreplace)
        self.assertRaises(IndexError, self.encode, self.unmappedunicode,
                          'test.cjktest')

    def test_callback_None_index(self):
        def myreplace(exc):
            return ('x', None)
        codecs.register_error("test.cjktest", myreplace)
        self.assertRaises(TypeError, self.encode, self.unmappedunicode,
                          'test.cjktest')

    def test_callback_backward_index(self):
        def myreplace(exc):
            if myreplace.limit > 0:
                myreplace.limit -= 1
                return ('REPLACED', 0)
            else:
                return ('TERMINAL', exc.end)
        myreplace.limit = 3
        codecs.register_error("test.cjktest", myreplace)
        self.assertEqual(self.encode('abcd' + self.unmappedunicode + 'efgh',
                                     'test.cjktest'),
                (b'abcdREPLACEDabcdREPLACEDabcdREPLACEDabcdTERMINALefgh', 9))

    def test_callback_forward_index(self):
        def myreplace(exc):
            return ('REPLACED', exc.end + 2)
        codecs.register_error("test.cjktest", myreplace)
        self.assertEqual(self.encode('abcd' + self.unmappedunicode + 'efgh',
                                     'test.cjktest'), (b'abcdREPLACEDgh', 9))

    def test_callback_index_outofbound(self):
        def myreplace(exc):
            return ('TERM', 100)
        codecs.register_error("test.cjktest", myreplace)
        self.assertRaises(IndexError, self.encode, self.unmappedunicode,
                          'test.cjktest')

    def test_incrementalencoder(self):
        UTF8Reader = codecs.getreader('utf-8')
        for sizehint in [None] + list(range(1, 33)) + \
                        [64, 128, 256, 512, 1024]:
            istream = UTF8Reader(BytesIO(self.tstring[1]))
            ostream = BytesIO()
            encoder = self.incrementalencoder()
            while 1:
                if sizehint is not None:
                    data = istream.read(sizehint)
                else:
                    data = istream.read()

                if not data:
                    break
                e = encoder.encode(data)
                ostream.write(e)

            self.assertEqual(ostream.getvalue(), self.tstring[0])

    def test_incrementaldecoder(self):
        UTF8Writer = codecs.getwriter('utf-8')
        for sizehint in [None, -1] + list(range(1, 33)) + \
                        [64, 128, 256, 512, 1024]:
            istream = BytesIO(self.tstring[0])
            ostream = UTF8Writer(BytesIO())
            decoder = self.incrementaldecoder()
            while 1:
                data = istream.read(sizehint)
                if not data:
                    break
                else:
                    u = decoder.decode(data)
                    ostream.write(u)

            self.assertEqual(ostream.getvalue(), self.tstring[1])

    def test_incrementalencoder_error_callback(self):
        inv = self.unmappedunicode

        e = self.incrementalencoder()
        self.assertRaises(UnicodeEncodeError, e.encode, inv, True)

        e.errors = 'ignore'
        self.assertEqual(e.encode(inv, True), b'')

        e.reset()
        def tempreplace(exc):
            return ('called', exc.end)
        codecs.register_error('test.incremental_error_callback', tempreplace)
        e.errors = 'test.incremental_error_callback'
        self.assertEqual(e.encode(inv, True), b'called')

        # again
        e.errors = 'ignore'
        self.assertEqual(e.encode(inv, True), b'')

    def test_streamreader(self):
        UTF8Writer = codecs.getwriter('utf-8')
        for name in ["read", "readline", "readlines"]:
            for sizehint in [None, -1] + list(range(1, 33)) + \
                            [64, 128, 256, 512, 1024]:
                istream = self.reader(BytesIO(self.tstring[0]))
                ostream = UTF8Writer(BytesIO())
                func = getattr(istream, name)
                while 1:
                    data = func(sizehint)
                    if not data:
                        break
                    if name == "readlines":
                        ostream.writelines(data)
                    else:
                        ostream.write(data)

                self.assertEqual(ostream.getvalue(), self.tstring[1])

    def test_streamwriter(self):
        readfuncs = ('read', 'readline', 'readlines')
        UTF8Reader = codecs.getreader('utf-8')
        for name in readfuncs:
            for sizehint in [None] + list(range(1, 33)) + \
                            [64, 128, 256, 512, 1024]:
                istream = UTF8Reader(BytesIO(self.tstring[1]))
                ostream = self.writer(BytesIO())
                func = getattr(istream, name)
                while 1:
                    if sizehint is not None:
                        data = func(sizehint)
                    else:
                        data = func()

                    if not data:
                        break
                    if name == "readlines":
                        ostream.writelines(data)
                    else:
                        ostream.write(data)

                self.assertEqual(ostream.getvalue(), self.tstring[0])


class TestBase_Mapping(unittest.TestCase):
    pass_enctest = []
    pass_dectest = []
    supmaps = []
    codectests = []

    def __init__(self, *args, **kw):
        unittest.TestCase.__init__(self, *args, **kw)
        try:
            self.open_mapping_file().close() # test it to report the error early
        except (IOError, HTTPException):
            self.skipTest("Could not retrieve "+self.mapfileurl)

    def open_mapping_file(self):
        return support.open_urlresource(self.mapfileurl)

    def test_mapping_file(self):
        if self.mapfileurl.endswith('.xml'):
            self._test_mapping_file_ucm()
        else:
            self._test_mapping_file_plain()

    def _test_mapping_file_plain(self):
        unichrs = lambda s: ''.join(map(chr, map(eval, s.split('+'))))
        urt_wa = {}

        with self.open_mapping_file() as f:
            for line in f:
                if not line:
                    break
                data = line.split('#')[0].strip().split()
                if len(data) != 2:
                    continue

                csetval = eval(data[0])
                if csetval <= 0x7F:
                    csetch = bytes([csetval & 0xff])
                elif csetval >= 0x1000000:
                    csetch = bytes([(csetval >> 24), ((csetval >> 16) & 0xff),
                                    ((csetval >> 8) & 0xff), (csetval & 0xff)])
                elif csetval >= 0x10000:
                    csetch = bytes([(csetval >> 16), ((csetval >> 8) & 0xff),
                                    (csetval & 0xff)])
                elif csetval >= 0x100:
                    csetch = bytes([(csetval >> 8), (csetval & 0xff)])
                else:
                    continue

                unich = unichrs(data[1])
                if ord(unich) == 0xfffd or unich in urt_wa:
                    continue
                urt_wa[unich] = csetch

                self._testpoint(csetch, unich)

    def _test_mapping_file_ucm(self):
        with self.open_mapping_file() as f:
            ucmdata = f.read()
        uc = re.findall('<a u="([A-F0-9]{4})" b="([0-9A-F ]+)"/>', ucmdata)
        for uni, coded in uc:
            unich = chr(int(uni, 16))
            codech = bytes(int(c, 16) for c in coded.split())
            self._testpoint(codech, unich)

    def test_mapping_supplemental(self):
        for mapping in self.supmaps:
            self._testpoint(*mapping)

    def _testpoint(self, csetch, unich):
        if (csetch, unich) not in self.pass_enctest:
            self.assertEqual(unich.encode(self.encoding), csetch)
        if (csetch, unich) not in self.pass_dectest:
            self.assertEqual(str(csetch, self.encoding), unich)

    def test_errorhandle(self):
        for source, scheme, expected in self.codectests:
            if isinstance(source, bytes):
                func = source.decode
            else:
                func = source.encode
            if expected:
                if isinstance(source, bytes):
                    result = func(self.encoding, scheme)
                    self.assertTrue(type(result) is str, type(result))
                    self.assertEqual(result, expected,
                                     '%a.decode(%r, %r)=%a != %a'
                                     % (source, self.encoding, scheme, result,
                                        expected))
                else:
                    result = func(self.encoding, scheme)
                    self.assertTrue(type(result) is bytes, type(result))
                    self.assertEqual(result, expected,
                                     '%a.encode(%r, %r)=%a != %a'
                                     % (source, self.encoding, scheme, result,
                                        expected))
            else:
                self.assertRaises(UnicodeError, func, self.encoding, scheme)

def load_teststring(name):
    dir = os.path.join(os.path.dirname(__file__), 'cjkencodings')
    with open(os.path.join(dir, name + '.txt'), 'rb') as f:
        encoded = f.read()
    with open(os.path.join(dir, name + '-utf8.txt'), 'rb') as f:
        utf8 = f.read()
    return encoded, utf8
098' href='#n1098'>1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 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/*
 * tclPathObj.c --
 *
 *	This file contains the implementation of Tcl's "path" object type used
 *	to represent and manipulate a general (virtual) filesystem entity in
 *	an efficient manner.
 *
 * Copyright (c) 2003 Vince Darley.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tclInt.h"
#include "tclFileSystem.h"

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

static Tcl_Obj *	AppendPath(Tcl_Obj *head, Tcl_Obj *tail);
static void		DupFsPathInternalRep(Tcl_Obj *srcPtr,
			    Tcl_Obj *copyPtr);
static void		FreeFsPathInternalRep(Tcl_Obj *pathPtr);
static void		UpdateStringOfFsPath(Tcl_Obj *pathPtr);
static int		SetFsPathFromAny(Tcl_Interp *interp, Tcl_Obj *pathPtr);
static int		FindSplitPos(const char *path, int separator);
static int		IsSeparatorOrNull(int ch);
static Tcl_Obj *	GetExtension(Tcl_Obj *pathPtr);
static int		MakePathFromNormalized(Tcl_Interp *interp,
			    Tcl_Obj *pathPtr);

/*
 * Define the 'path' object type, which Tcl uses to represent file paths
 * internally.
 */

static Tcl_ObjType tclFsPathType = {
    "path",				/* name */
    FreeFsPathInternalRep,		/* freeIntRepProc */
    DupFsPathInternalRep,		/* dupIntRepProc */
    UpdateStringOfFsPath,		/* updateStringProc */
    SetFsPathFromAny			/* setFromAnyProc */
};

/*
 * 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 both 'translatedPathPtr' and 'normPathPtr' can be a circular
 * reference to the container Tcl_Obj of this FsPath.
 *
 * There are two cases, with the first being the most common:
 *
 * (i) flags == 0, => Ordinary path.
 *
 * translatedPathPtr contains the translated path (which may be a circular
 * reference to the object itself). If it is NULL then the path is pure
 * normalized (and the normPathPtr will be a circular reference). cwdPtr is
 * null for an absolute path, and non-null for a relative path (unless the cwd
 * has never been set, in which case the cwdPtr may also be null for a
 * relative path).
 *
 * (ii) flags != 0, => Special path, see TclNewFSPathObj
 *
 * Now, this is a path like 'file join $dir $tail' where, cwdPtr is the $dir
 * and normPathPtr is the $tail.
 *
 */

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 - see
				 * below. */
    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. */
    Tcl_Filesystem *fsPtr;	/* The Tcl_Filesystem that claims this path */
} FsPath;

/*
 * Flag values for FsPath->flags.
 */

#define TCLPATH_APPENDED 1
#define TCLPATH_NEEDNORM 4

/*
 * Define some macros to give us convenient access to path-object specific
 * fields.
 */

#define PATHOBJ(pathPtr) ((FsPath *) (pathPtr)->internalRep.twoPtrValue.ptr1)
#define SETPATHOBJ(pathPtr,fsPathPtr) \
	((pathPtr)->internalRep.twoPtrValue.ptr1 = (void *) (fsPathPtr))
#define PATHFLAGS(pathPtr) (PATHOBJ(pathPtr)->flags)

/*
 *---------------------------------------------------------------------------
 *
 * TclFSNormalizeAbsolutePath --
 *
 *	Takes an absolute path specification and computes a 'normalized' path
 *	from it.
 *
 *	A normalized path is one which has all '../', './' removed. Also it is
 *	one which is in the 'standard' format for the native platform. On
 *	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 us a unique, case-dependent path).
 *
 *	The behaviour of this function if passed a non-absolute path is NOT
 *	defined.
 *
 *	pathPtr may have a refCount of zero, or may be a shared object.
 *
 * Results:
 *	The result is returned in a Tcl_Obj with a refCount of 1, which is
 *	therefore owned by the caller. It must be freed (with
 *	Tcl_DecrRefCount) by the caller when no longer needed.
 *
 * Side effects:
 *	None (beyond the memory allocation for the result).
 *
 * Special note:
 *	This code was originally based on code from Matt Newman and
 *	Jean-Claude Wippler, but has since been totally rewritten by Vince
 *	Darley to deal with symbolic links.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
TclFSNormalizeAbsolutePath(
    Tcl_Interp *interp,		/* Interpreter to use */
    Tcl_Obj *pathPtr)		/* Absolute path to normalize */
{
    const char *dirSep, *oldDirSep;
    int first = 1;		/* Set to zero once we've passed the first
				 * directory separator - we can't use '..' to
				 * remove the volume in a path. */
    Tcl_Obj *retVal = NULL;
    dirSep = TclGetString(pathPtr);

    if (tclPlatform == TCL_PLATFORM_WINDOWS) {
	if (   (dirSep[0] == '/' || dirSep[0] == '\\')
	    && (dirSep[1] == '/' || dirSep[1] == '\\')
	    && (dirSep[2] == '?')
	    && (dirSep[3] == '/' || dirSep[3] == '\\')) {
	    /* NT extended path */
	    dirSep += 4;

	    if (   (dirSep[0] == 'U' || dirSep[0] == 'u')
		&& (dirSep[1] == 'N' || dirSep[1] == 'n')
		&& (dirSep[2] == 'C' || dirSep[2] == 'c')
		&& (dirSep[3] == '/' || dirSep[3] == '\\')) {
		/* NT extended UNC path */
		dirSep += 4;
	    }
	}
	if (dirSep[0] != 0 && dirSep[1] == ':' &&
		(dirSep[2] == '/' || dirSep[2] == '\\')) {
	    /* Do nothing */
	} else if ((dirSep[0] == '/' || dirSep[0] == '\\')
		&& (dirSep[1] == '/' || dirSep[1] == '\\')) {
	    /*
	     * UNC style path, where we must skip over the first separator,
	     * since the first two segments are actually inseparable.
	     */

	    dirSep += 2;
	    dirSep += FindSplitPos(dirSep, '/');
	    if (*dirSep != 0) {
		dirSep++;
	    }
	}
    }

    /*
     * Scan forward from one directory separator to the next, checking for
     * '..' and '.' sequences which must be handled specially. In particular
     * handling of '..' can be complicated if the directory before is a link,
     * since we will have to expand the link to be able to back up one level.
     */

    while (*dirSep != 0) {
	oldDirSep = dirSep;
	if (!first) {
	    dirSep++;
	}
	dirSep += FindSplitPos(dirSep, '/');
	if (dirSep[0] == 0 || dirSep[1] == 0) {
	    if (retVal != NULL) {
		Tcl_AppendToObj(retVal, oldDirSep, dirSep - oldDirSep);
	    }
	    break;
	}
	if (dirSep[1] == '.') {
	    if (retVal != NULL) {
		Tcl_AppendToObj(retVal, oldDirSep, dirSep - oldDirSep);
		oldDirSep = dirSep;
	    }
	again:
	    if (IsSeparatorOrNull(dirSep[2])) {
		/*
		 * Need to skip '.' in the path.
		 */
		int curLen;

		if (retVal == NULL) {
		    const char *path = TclGetString(pathPtr);
		    retVal = Tcl_NewStringObj(path, dirSep - path);
		    Tcl_IncrRefCount(retVal);
		}
		(void) Tcl_GetStringFromObj(retVal, &curLen);
		if (curLen == 0) {
		    Tcl_AppendToObj(retVal, dirSep, 1);
		}
		dirSep += 2;
		oldDirSep = dirSep;
		if (dirSep[0] != 0 && dirSep[1] == '.') {
		    goto again;
		}
		continue;
	    }
	    if (dirSep[2] == '.' && IsSeparatorOrNull(dirSep[3])) {
		Tcl_Obj *link;
		int curLen;
		char *linkStr;

		/*
		 * Have '..' so need to skip previous directory.
		 */

		if (retVal == NULL) {
		    const char *path = TclGetString(pathPtr);

		    retVal = Tcl_NewStringObj(path, dirSep - path);
		    Tcl_IncrRefCount(retVal);
		}
		(void) Tcl_GetStringFromObj(retVal, &curLen);
		if (curLen == 0) {
		    Tcl_AppendToObj(retVal, dirSep, 1);
		}
		if (!first || (tclPlatform == TCL_PLATFORM_UNIX)) {
		    link = Tcl_FSLink(retVal, NULL, 0);

		    /* Safety check in case driver caused sharing */
		    if (Tcl_IsShared(retVal)) {
			TclDecrRefCount(retVal);
			retVal = Tcl_DuplicateObj(retVal);
			Tcl_IncrRefCount(retVal);
		    }

		    if (link != NULL) {
			/*
			 * Got a link. Need to check if the link is relative
			 * or absolute, for those platforms where relative
			 * links exist.
			 */

			if (tclPlatform != TCL_PLATFORM_WINDOWS &&
				Tcl_FSGetPathType(link) == TCL_PATH_RELATIVE) {
			    /*
			     * We need to follow this link which is relative
			     * to retVal's directory. This means concatenating
			     * the link onto the directory of the path so far.
			     */

			    const char *path =
				    Tcl_GetStringFromObj(retVal, &curLen);

			    while (--curLen >= 0) {
				if (IsSeparatorOrNull(path[curLen])) {
				    break;
				}
			    }

			    /*
			     * We want the trailing slash.
			     */

			    Tcl_SetObjLength(retVal, curLen+1);
			    Tcl_AppendObjToObj(retVal, link);
			    TclDecrRefCount(link);
			    linkStr = Tcl_GetStringFromObj(retVal, &curLen);
			} else {
			    /*
			     * Absolute link.
			     */

			    TclDecrRefCount(retVal);
			    if (Tcl_IsShared(link)) {
				retVal = Tcl_DuplicateObj(link);
				TclDecrRefCount(link);
			    } else {
				retVal = link;
			    }
			    linkStr = Tcl_GetStringFromObj(retVal, &curLen);

			    /*
			     * Convert to forward-slashes on windows.
			     */

			    if (tclPlatform == TCL_PLATFORM_WINDOWS) {
				int i;

				for (i = 0; i < curLen; i++) {
				    if (linkStr[i] == '\\') {
					linkStr[i] = '/';
				    }
				}
			    }
			}
		    } else {
			linkStr = Tcl_GetStringFromObj(retVal, &curLen);
		    }

		    /*
		     * Either way, we now remove the last path element.
		     * (but not the first character of the path)
		     */

		    while (--curLen >= 0) {
			if (IsSeparatorOrNull(linkStr[curLen])) {
			    if (curLen) {
				Tcl_SetObjLength(retVal, curLen);
			    } else {
				Tcl_SetObjLength(retVal, 1);
			    }
			    break;
			}
		    }
		}
		dirSep += 3;
		oldDirSep = dirSep;

		if ((curLen == 0) && (dirSep[0] != 0)) {
		    Tcl_SetObjLength(retVal, 0);
		}

		if (dirSep[0] != 0 && dirSep[1] == '.') {
		    goto again;
		}
		continue;
	    }
	}
	first = 0;
	if (retVal != NULL) {
	    Tcl_AppendToObj(retVal, oldDirSep, dirSep - oldDirSep);
	}
    }

    /*
     * If we didn't make any changes, just use the input path.
     */

    if (retVal == NULL) {
	retVal = pathPtr;
	Tcl_IncrRefCount(retVal);

	if (Tcl_IsShared(retVal)) {
	    /*
	     * Unfortunately, the platform-specific normalization code which
	     * will be called below has no way of dealing with the case where
	     * an object is shared. It is expecting to modify an object in
	     * place. So, we must duplicate this here to ensure an object with
	     * a single ref-count.
	     *
	     * If that changes in the future (e.g. the normalize proc is given
	     * one object and is able to return a different one), then we
	     * could remove this code.
	     */

	    TclDecrRefCount(retVal);
	    retVal = Tcl_DuplicateObj(pathPtr);
	    Tcl_IncrRefCount(retVal);
	}
    }

    /*
     * Ensure a windows drive like C:/ has a trailing separator
     */

    if (tclPlatform == TCL_PLATFORM_WINDOWS) {
	int len;
	const char *path = Tcl_GetStringFromObj(retVal, &len);

	if (len == 2 && path[0] != 0 && path[1] == ':') {
	    if (Tcl_IsShared(retVal)) {
		TclDecrRefCount(retVal);
		retVal = Tcl_DuplicateObj(retVal);
		Tcl_IncrRefCount(retVal);
	    }
	    Tcl_AppendToObj(retVal, "/", 1);
	}
    }

    /*
     * 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).
     *
     * Virtual file systems which may be registered may have other criteria
     * for normalizing a path.
     */

    TclFSNormalizeToUniquePath(interp, retVal, 0);

    /*
     * Since we know it is a normalized path, we can actually convert this
     * object into an FsPath for greater efficiency
     */

    MakePathFromNormalized(interp, retVal);

    /*
     * This has a refCount of 1 for the caller, unlike many Tcl_Obj APIs.
     */

    return retVal;
}

/*
 *----------------------------------------------------------------------
 *
 * 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(
    Tcl_Obj *pathPtr)
{
    return TclFSGetPathType(pathPtr, NULL, NULL);
}

/*
 *----------------------------------------------------------------------
 *
 * TclFSGetPathType --
 *
 *	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.
 *
 *----------------------------------------------------------------------
 */

Tcl_PathType
TclFSGetPathType(
    Tcl_Obj *pathPtr,
    Tcl_Filesystem **filesystemPtrPtr,
    int *driveNameLengthPtr)
{
    FsPath *fsPathPtr;

    if (Tcl_FSConvertToPathType(NULL, pathPtr) != TCL_OK) {
	return TclGetPathType(pathPtr, filesystemPtrPtr, driveNameLengthPtr,
		NULL);
    }

    fsPathPtr = PATHOBJ(pathPtr);
    if (fsPathPtr->cwdPtr == NULL) {
	return TclGetPathType(pathPtr, filesystemPtrPtr, driveNameLengthPtr,
		NULL);
    }

    if (PATHFLAGS(pathPtr) == 0) {
	/* The path is not absolute... */
#ifdef __WIN32__
	/* ... on Windows we must make another call to determine whether
	 * it's relative or volumerelative [Bug 2571597]. */
	return TclGetPathType(pathPtr, filesystemPtrPtr, driveNameLengthPtr,
		NULL);
#else
	/* On other systems, quickly deduce !absolute -> relative */
	return TCL_PATH_RELATIVE;
#endif
    }
    return TclFSGetPathType(fsPathPtr->cwdPtr, filesystemPtrPtr,
	    driveNameLengthPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * TclPathPart
 *
 *	This function calculates the requested part of the given path, which
 *	can be:
 *
 *	- the directory above ('file dirname')
 *	- the tail            ('file tail')
 *	- the extension       ('file extension')
 *	- the root            ('file root')
 *
 *	The 'portion' parameter dictates which of these to calculate. There
 *	are a number of special cases both to be more efficient, and because
 *	the behaviour when given a path with only a single element is defined
 *	to require the expansion of that single element, where possible.
 *
 *	Should look into integrating 'FileBasename' in tclFCmd.c into this
 *	function.
 *
 * Results:
 *	NULL if an error occurred, otherwise a Tcl_Obj owned by the caller
 *	(i.e. most likely with refCount 1).
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
TclPathPart(
    Tcl_Interp *interp,		/* Used for error reporting */
    Tcl_Obj *pathPtr,		/* Path to take dirname of */
    Tcl_PathPart portion)	/* Requested portion of name */
{
    if (pathPtr->typePtr == &tclFsPathType) {
	FsPath *fsPathPtr = PATHOBJ(pathPtr);

	if (PATHFLAGS(pathPtr) != 0) {
	    switch (portion) {
	    case TCL_PATH_DIRNAME: {
		/*
		 * Check if the joined-on bit has any directory delimiters in
		 * it. If so, the 'dirname' would be a joining of the main
		 * part with the dirname of the joined-on bit. We could handle
		 * that special case here, but we don't, and instead just use
		 * the standardPath code.
		 */

		int numBytes;
		const char *rest =
			Tcl_GetStringFromObj(fsPathPtr->normPathPtr, &numBytes);

		if (strchr(rest, '/') != NULL) {
		    goto standardPath;
		}
		/*
		 * If the joined-on bit is empty, then [file dirname] is
		 * documented to return all but the last non-empty element
		 * of the path, so we need to split apart the main part to
		 * get the right answer.  We could do that here, but it's
		 * simpler to fall back to the standardPath code.
		 * [Bug 2710920]
		 */
		if (numBytes == 0) {
		    goto standardPath;
		}
		if (tclPlatform == TCL_PLATFORM_WINDOWS
			&& strchr(rest, '\\') != NULL) {
		    goto standardPath;
		}

		/*
		 * The joined-on path is simple, so we can just return here.
		 */

		Tcl_IncrRefCount(fsPathPtr->cwdPtr);
		return fsPathPtr->cwdPtr;
	    }
	    case TCL_PATH_TAIL: {
		/*
		 * Check if the joined-on bit has any directory delimiters in
		 * it. If so, the 'tail' would be only the part following the
		 * last delimiter. We could handle that special case here, but
		 * we don't, and instead just use the standardPath code.
		 */

		int numBytes;
		const char *rest =
			Tcl_GetStringFromObj(fsPathPtr->normPathPtr, &numBytes);

		if (strchr(rest, '/') != NULL) {
		    goto standardPath;
		}
		/*
		 * If the joined-on bit is empty, then [file tail] is
		 * documented to return the last non-empty element
		 * of the path, so we need to split off the last element
		 * of the main part to get the right answer.  We could do
		 * that here, but it's simpler to fall back to the
		 * standardPath code.  [Bug 2710920]
		 */
		if (numBytes == 0) {
		    goto standardPath;
		}
		if (tclPlatform == TCL_PLATFORM_WINDOWS
			&& strchr(rest, '\\') != NULL) {
		    goto standardPath;
		}
		Tcl_IncrRefCount(fsPathPtr->normPathPtr);
		return fsPathPtr->normPathPtr;
	    }
	    case TCL_PATH_EXTENSION:
		return GetExtension(fsPathPtr->normPathPtr);
	    case TCL_PATH_ROOT: {
		const char *fileName, *extension;
		int length;

		fileName = Tcl_GetStringFromObj(fsPathPtr->normPathPtr,
			&length);
		extension = TclGetExtension(fileName);
		if (extension == NULL) {
		    /*
		     * There is no extension so the root is the same as the
		     * path we were given.
		     */

		    Tcl_IncrRefCount(pathPtr);
		    return pathPtr;
		} else {
		    /*
		     * Need to return the whole path with the extension
		     * suffix removed.  Do that by joining our "head" to
		     * our "tail" with the extension suffix removed from
		     * the tail.
		     */

		    Tcl_Obj *resultPtr =
			    TclNewFSPathObj(fsPathPtr->cwdPtr, fileName,
			    (int)(length - strlen(extension)));

		    Tcl_IncrRefCount(resultPtr);
		    return resultPtr;
		}
	    }
	    default:
		/* We should never get here */
		Tcl_Panic("Bad portion to TclPathPart");
		/* For less clever compilers */
		return NULL;
	    }
	} else if (fsPathPtr->cwdPtr != NULL) {
	    /* Relative path */
	    goto standardPath;
	} else {
	    /* Absolute path */
	    goto standardPath;
	}
    } else {
	int splitElements;
	Tcl_Obj *splitPtr, *resultPtr;

    standardPath:
	resultPtr = NULL;
	if (portion == TCL_PATH_EXTENSION) {
	    return GetExtension(pathPtr);
	} else if (portion == TCL_PATH_ROOT) {
	    int length;
	    const char *fileName, *extension;

	    fileName = Tcl_GetStringFromObj(pathPtr, &length);
	    extension = TclGetExtension(fileName);
	    if (extension == NULL) {
		Tcl_IncrRefCount(pathPtr);
		return pathPtr;
	    } else {
		Tcl_Obj *root = Tcl_NewStringObj(fileName,
			(int) (length - strlen(extension)));

		Tcl_IncrRefCount(root);
		return root;
	    }
	}

	/*
	 * The behaviour we want here is slightly different to the standard
	 * Tcl_FSSplitPath in the handling of home directories;
	 * Tcl_FSSplitPath preserves the "~" while this code computes the
	 * actual full path name, if we had just a single component.
	 */

	splitPtr = Tcl_FSSplitPath(pathPtr, &splitElements);
	Tcl_IncrRefCount(splitPtr);
	if (splitElements == 1  &&  TclGetString(pathPtr)[0] == '~') {
	    Tcl_Obj *norm;

	    TclDecrRefCount(splitPtr);
	    norm = Tcl_FSGetNormalizedPath(interp, pathPtr);
	    if (norm == NULL) {
		return NULL;
	    }
	    splitPtr = Tcl_FSSplitPath(norm, &splitElements);
	    Tcl_IncrRefCount(splitPtr);
	}
	if (portion == TCL_PATH_TAIL) {
	    /*
	     * Return the last component, unless it is the only component, and
	     * it is the root of an absolute path.
	     */

	    if ((splitElements > 0) && ((splitElements > 1) ||
		    (Tcl_FSGetPathType(pathPtr) == TCL_PATH_RELATIVE))) {
		Tcl_ListObjIndex(NULL, splitPtr, splitElements-1, &resultPtr);
	    } else {
		resultPtr = Tcl_NewObj();
	    }
	} else {
	    /*
	     * Return all but the last component. If there is only one
	     * component, return it if the path was non-relative, otherwise
	     * return the current directory.
	     */

	    if (splitElements > 1) {
		resultPtr = Tcl_FSJoinPath(splitPtr, splitElements - 1);
	    } else if (splitElements == 0 ||
		    (Tcl_FSGetPathType(pathPtr) == TCL_PATH_RELATIVE)) {
		TclNewLiteralStringObj(resultPtr, ".");
	    } else {
		Tcl_ListObjIndex(NULL, splitPtr, 0, &resultPtr);
	    }
	}
	Tcl_IncrRefCount(resultPtr);
	TclDecrRefCount(splitPtr);
	return resultPtr;
    }
}

/*
 * Simple helper function
 */

static Tcl_Obj *
GetExtension(
    Tcl_Obj *pathPtr)
{
    const char *tail, *extension;
    Tcl_Obj *ret;

    tail = TclGetString(pathPtr);
    extension = TclGetExtension(tail);
    if (extension == NULL) {
	ret = Tcl_NewObj();
    } else {
	ret = Tcl_NewStringObj(extension, -1);
    }
    Tcl_IncrRefCount(ret);
    return ret;
}

/*
 *---------------------------------------------------------------------------
 *
 * 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 (each path segment may be a complete
 *	path, a partial path or just a single possible directory or file
 *	name). If any path segment is actually an absolute path, then all
 *	prior path segments are discarded.
 *
 *	If elements < 0, we use the entire list that was given.
 *
 *	It is possible that the returned object is actually an element of the
 *	given list, so the caller should be careful to store a refCount to it
 *	before freeing the 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. Note that in the case where the caller has
 *	asked to join zero elements of the list, the return value will be an
 *	empty-string Tcl_Obj.
 *
 *	If the given listObj was invalid, then the calling routine has a bug,
 *	and this function will just return NULL.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSJoinPath(
    Tcl_Obj *listObj,		/* Path elements to join, may have a zero
				 * reference count. */
    int elements)		/* Number of elements to use (-1 = all) */
{
    Tcl_Obj *res;
    int i;
    Tcl_Filesystem *fsPtr = NULL;

    if (elements < 0) {
	if (Tcl_ListObjLength(NULL, listObj, &elements) != TCL_OK) {
	    return NULL;
	}
    } else {
	/*
	 * Just make sure it is a valid list.
	 */

	int listTest;

	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;
	}
    }

    res = NULL;

    for (i = 0; i < elements; i++) {
	Tcl_Obj *elt, *driveName = NULL;
	int driveNameLength, strEltLen, length;
	Tcl_PathType type;
	char *strElt, *ptr;

	Tcl_ListObjIndex(NULL, listObj, i, &elt);

	/*
	 * This is a special case where we can be much more efficient, where
	 * we are joining a single relative path onto an object that is
	 * already of path type. The 'TclNewFSPathObj' call below creates an
	 * object which can be normalized more efficiently. Currently we only
	 * use the special case when we have exactly two elements, but we
	 * could expand that in the future.
	 */

	if ((i == (elements-2)) && (i == 0) && (elt->typePtr == &tclFsPathType)
		&& !(elt->bytes != NULL && (elt->bytes[0] == '\0'))) {
	    Tcl_Obj *tail;

	    Tcl_ListObjIndex(NULL, listObj, i+1, &tail);
	    type = TclGetPathType(tail, NULL, NULL, NULL);
	    if (type == TCL_PATH_RELATIVE) {
		const char *str;
		int len;

		str = Tcl_GetStringFromObj(tail, &len);
		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!
		     */

		    if (res != NULL) {
			TclDecrRefCount(res);
		    }
		    return elt;
		}

		/*
		 * If it doesn't begin with '.' and is a unix path or it a
		 * windows path without backslashes, then we can be very
		 * efficient here. (In fact even a windows path with
		 * backslashes can be joined efficiently, but the path object
		 * would not have forward slashes only, and this would
		 * therefore contradict our 'file join' documentation).
		 */

		if (str[0] != '.' && ((tclPlatform != TCL_PLATFORM_WINDOWS)
			|| (strchr(str, '\\') == NULL))) {
		    /*
		     * Finally, on Windows, 'file join' is defined to convert
		     * all backslashes to forward slashes, so the base part
		     * cannot have backslashes either.
		     */

		    if ((tclPlatform != TCL_PLATFORM_WINDOWS)
			    || (strchr(Tcl_GetString(elt), '\\') == NULL)) {
			if (res != NULL) {
			    TclDecrRefCount(res);
			}
			return TclNewFSPathObj(elt, str, len);
		    }
		}

		/*
		 * Otherwise we don't have an easy join, and we must let the
		 * more general code below handle things.
		 */
	    } else if (tclPlatform == TCL_PLATFORM_UNIX) {
		if (res != NULL) {
		    TclDecrRefCount(res);
		}
		return tail;
	    } else {
		const char *str = TclGetString(tail);

		if (tclPlatform == TCL_PLATFORM_WINDOWS) {
		    if (strchr(str, '\\') == NULL) {
			if (res != NULL) {
			    TclDecrRefCount(res);
			}
			return tail;
		    }
		}
	    }
	}
	strElt = Tcl_GetStringFromObj(elt, &strEltLen);
	type = TclGetPathType(elt, &fsPtr, &driveNameLength, &driveName);
	if (type != TCL_PATH_RELATIVE) {
	    /*
	     * Zero out the current result.
	     */

	    if (res != NULL) {
		TclDecrRefCount(res);
	    }

	    if (driveName != NULL) {
		/*
		 * We've been given a separate drive-name object, because the
		 * prefix in 'elt' is not in a suitable format for us (e.g. it
		 * may contain irrelevant multiple separators, like
		 * C://///foo).
		 */

		res = Tcl_DuplicateObj(driveName);
		TclDecrRefCount(driveName);

		/*
		 * Do not set driveName to NULL, because we will check its
		 * value below (but we won't access the contents, since those
		 * have been cleaned-up).
		 */
	    } else {
		res = Tcl_NewStringObj(strElt, driveNameLength);
	    }
	    strElt += driveNameLength;
	} else if (driveName != NULL) {
	    Tcl_DecrRefCount(driveName);
	}

	/*
	 * Optimisation block: if this is the last element to be examined, and
	 * it is absolute or the only element, and the drive-prefix was ok (if
	 * there is one), it might be that the path is already in a suitable
	 * form to be returned. Then we can short-cut the rest of this
	 * function.
	 */

	if ((driveName == NULL) && (i == (elements - 1))
		&& (type != TCL_PATH_RELATIVE || res == NULL)) {
	    /*
	     * It's the last path segment. Perform a quick check if the path
	     * is already in a suitable form.
	     */

	    if (tclPlatform == TCL_PLATFORM_WINDOWS) {
		if (strchr(strElt, '\\') != NULL) {
		    goto noQuickReturn;
		}
	    }
	    ptr = strElt;
	    while (*ptr != '\0') {
		if (*ptr == '/' && (ptr[1] == '/' || ptr[1] == '\0')) {
		    /*
		     * We have a repeated file separator, which means the path
		     * is not in normalized form
		     */

		    goto noQuickReturn;
		}
		ptr++;
	    }
	    if (res != NULL) {
		TclDecrRefCount(res);
	    }

	    /*
	     * This element is just what we want to return already - no
	     * further manipulation is requred.
	     */

	    return elt;
	}

	/*
	 * The path element was not of a suitable form to be returned as is.
	 * We need to perform a more complex operation here.
	 */

    noQuickReturn:
	if (res == NULL) {
	    res = Tcl_NewObj();
	    ptr = Tcl_GetStringFromObj(res, &length);
	} else {
	    ptr = Tcl_GetStringFromObj(res, &length);
	}

	/*
	 * Strip off any './' before a tilde, unless this is the beginning of
	 * the path.
	 */

	if (length > 0 && strEltLen > 0 && (strElt[0] == '.') &&
		(strElt[1] == '/') && (strElt[2] == '~')) {
	    strElt += 2;
	}

	/*
	 * 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 {
	    char separator = '/';
	    int needsSep = 0;

	    if (fsPtr->filesystemSeparatorProc != NULL) {
		Tcl_Obj *sep = (*fsPtr->filesystemSeparatorProc)(res);

		if (sep != NULL) {
		    separator = TclGetString(sep)[0];
		}
		/* Safety check in case the VFS driver caused sharing */
		if (Tcl_IsShared(res)) {
		    TclDecrRefCount(res);
		    res = Tcl_DuplicateObj(res);
		    Tcl_IncrRefCount(res);
		}
	    }

	    if (length > 0 && ptr[length -1] != '/') {
		Tcl_AppendToObj(res, &separator, 1);
		Tcl_GetStringFromObj(res, &length);
	    }
	    Tcl_SetObjLength(res, length + (int) strlen(strElt));

	    ptr = TclGetString(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 - TclGetString(res);
	    Tcl_SetObjLength(res, length);
	}
    }
    if (res == NULL) {
	res = Tcl_NewObj();
    }
    return res;
}

/*
 *---------------------------------------------------------------------------
 *
 * 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(
    Tcl_Interp *interp,		/* Interpreter in which to store error message
				 * (if necessary). */
    Tcl_Obj *pathPtr)		/* 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 (pathPtr->typePtr == &tclFsPathType) {
	if (TclFSEpochOk(PATHOBJ(pathPtr)->filesystemEpoch)) {
	    return TCL_OK;
	}

	if (pathPtr->bytes == NULL) {
	    UpdateStringOfFsPath(pathPtr);
	}
	FreeFsPathInternalRep(pathPtr);
    }

    return Tcl_ConvertToType(interp, pathPtr, &tclFsPathType);

    /*
     * We used to have more complex code here:
     *
     * FsPath *fsPathPtr = PATHOBJ(pathPtr);
     * if (fsPathPtr->cwdPtr == NULL || PATHFLAGS(pathPtr) != 0) {
     *     return TCL_OK;
     * } else {
     *     if (TclFSCwdPointerEquals(&fsPathPtr->cwdPtr)) {
     *         return TCL_OK;
     *     } else {
     *         if (pathPtr->bytes == NULL) {
     *             UpdateStringOfFsPath(pathPtr);
     *         }
     *         FreeFsPathInternalRep(pathPtr);
     *         return Tcl_ConvertToType(interp, pathPtr, &tclFsPathType);
     *     }
     * }
     *
     * But we no longer believe this is necessary.
     */
}

/*
 * Helper function for normalization.
 */

static int
IsSeparatorOrNull(
    int ch)
{
    if (ch == 0) {
	return 1;
    }
    switch (tclPlatform) {
    case TCL_PLATFORM_UNIX:
	return (ch == '/' ? 1 : 0);
    case TCL_PLATFORM_WINDOWS:
	return ((ch == '/' || ch == '\\') ? 1 : 0);
    }
    return 0;
}

/*
 * Helper function for SetFsPathFromAny. Returns position of first directory
 * delimiter in the path. If no separator is found, then returns the position
 * of the end of the string.
 */

static int
FindSplitPos(
    const char *path,
    int separator)
{
    int count = 0;
    switch (tclPlatform) {
    case TCL_PLATFORM_UNIX:
	while (path[count] != 0) {
	    if (path[count] == separator) {
		return count;
	    }
	    count++;
	}
	break;

    case TCL_PLATFORM_WINDOWS:
	while (path[count] != 0) {
	    if (path[count] == separator || path[count] == '\\') {
		return count;
	    }
	    count++;
	}
	break;
    }
    return count;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclNewFSPathObj --
 *
 *	Creates a path object whose string representation is '[file join
 *	dirPtr addStrRep]', but does so in a way that allows for more
 *	efficient creation and caching of normalized paths, and more efficient
 *	'file dirname', 'file tail', etc.
 *
 * Assumptions:
 *	'dirPtr' must be an absolute path. 'len' may not be zero.
 *
 * Results:
 *	The new Tcl object, with refCount zero.
 *
 * Side effects:
 *	Memory is allocated. 'dirPtr' gets an additional refCount.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
TclNewFSPathObj(
    Tcl_Obj *dirPtr,
    const char *addStrRep,
    int len)
{
    FsPath *fsPathPtr;
    Tcl_Obj *pathPtr;
    const char *p;
    int state = 0, count = 0;

    /* [Bug 2806250] - this is only a partial solution of the problem.
     * The PATHFLAGS != 0 representation assumes in many places that
     * the "tail" part stored in the normPathPtr field is itself a
     * relative path.  Strings that begin with "~" are not relative paths,
     * so we must prevent their storage in the normPathPtr field.
     *
     * More generally we ought to be testing "addStrRep" for any value
     * that is not a relative path, but in an unconstrained VFS world
     * that could be just about anything, and testing could be expensive.
     * Since this routine plays a big role in [glob], anything that slows
     * it down would be unwelcome.  For now, continue the risk of further
     * bugs when some Tcl_Filesystem uses otherwise relative path strings
     * as absolute path strings.  Sensible Tcl_Filesystems will avoid
     * that by mounting on path prefixes like foo:// which cannot be the
     * name of a file or directory read from a native [glob] operation.
     */
    if (addStrRep[0] == '~') {
	Tcl_Obj *tail = Tcl_NewStringObj(addStrRep, len);

	pathPtr = AppendPath(dirPtr, tail);
	Tcl_DecrRefCount(tail);
	return pathPtr;
    }

    pathPtr = Tcl_NewObj();
    fsPathPtr = (FsPath *) ckalloc(sizeof(FsPath));

    /*
     * Set up the path.
     */

    fsPathPtr->translatedPathPtr = NULL;
    fsPathPtr->normPathPtr = Tcl_NewStringObj(addStrRep, len);
    Tcl_IncrRefCount(fsPathPtr->normPathPtr);
    fsPathPtr->cwdPtr = dirPtr;
    Tcl_IncrRefCount(dirPtr);
    fsPathPtr->nativePathPtr = NULL;
    fsPathPtr->fsPtr = NULL;
    fsPathPtr->filesystemEpoch = 0;

    SETPATHOBJ(pathPtr, fsPathPtr);
    PATHFLAGS(pathPtr) = TCLPATH_APPENDED;
    pathPtr->typePtr = &tclFsPathType;
    pathPtr->bytes = NULL;
    pathPtr->length = 0;

    /*
     * Look for path components made up of only "."
     * This is overly conservative analysis to keep simple.  It may
     * mark some things as needing more aggressive normalization
     * that don't actually need it.  No harm done.
     */
    for (p = addStrRep; len > 0; p++, len--) {
       switch (state) {
       case 0: /* So far only "." since last dirsep or start */
           switch (*p) {
           case '.':
               count++;
               break;
           case '/':
           case '\\':
           case ':':
               if (count) {
                   PATHFLAGS(pathPtr) |= TCLPATH_NEEDNORM;
                   len = 0;
               }
               break;
           default:
               count = 0;
               state = 1;
           }
       case 1: /* Scanning for next dirsep */
           switch (*p) {
           case '/':
           case '\\':
           case ':':
               state = 0;
               break;
           }
       }
    }
    if (len == 0 && count) {
       PATHFLAGS(pathPtr) |= TCLPATH_NEEDNORM;
    }

    return pathPtr;
}

static Tcl_Obj *
AppendPath(
    Tcl_Obj *head,
    Tcl_Obj *tail)
{
    int numBytes;
    const char *bytes;
    Tcl_Obj *copy = Tcl_DuplicateObj(head);

    /*
     * This is likely buggy when dealing with virtual filesystem drivers
     * that use some character other than "/" as a path separator.  I know
     * of no evidence that such a foolish thing exists.  This solution was
     * chosen so that "JoinPath" operations that pass through either path
     * intrep produce the same results; that is, bugward compatibility.  If
     * we need to fix that bug here, it needs fixing in Tcl_FSJoinPath() too.
     */
    bytes = Tcl_GetStringFromObj(tail, &numBytes);
    if (numBytes == 0) {
	Tcl_AppendToObj(copy, "/", 1);
    } else {
	TclpNativeJoinPath(copy, bytes);
    }
    return copy;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclFSMakePathRelative --
 *
 *	Only for internal use.
 *
 *	Takes a path and a directory, where we _assume_ both path and
 *	directory are absolute, normalized and that the path lies inside the
 *	directory. Returns a Tcl_Obj representing filename of the path
 *	relative to the directory.
 *
 * Results:
 *	NULL on error, otherwise a valid object, typically with refCount of
 *	zero, which it is assumed the caller will increment.
 *
 * Side effects:
 *	The old representation may be freed, and new memory allocated.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
TclFSMakePathRelative(
    Tcl_Interp *interp,		/* Used for error reporting if not NULL. */
    Tcl_Obj *pathPtr,		/* The path we have. */
    Tcl_Obj *cwdPtr)		/* Make it relative to this. */
{
    int cwdLen, len;
    const char *tempStr;

    if (pathPtr->typePtr == &tclFsPathType) {
	FsPath *fsPathPtr = PATHOBJ(pathPtr);

	if (PATHFLAGS(pathPtr) != 0
		&& fsPathPtr->cwdPtr == cwdPtr) {
	    pathPtr = fsPathPtr->normPathPtr;

	    /* TODO: Determine how much, if any, of this forcing
	     * the relative path tail into the "path" Tcl_ObjType
	     * with a recorded cwdPtr context has any actual value.
	     *
	     * Nothing is getting cached.  Not normPathPtr, not nativePathPtr,
	     * nor fsPtr, so storing the cwdPtr context against which such
	     * cached values might later be validated appears to be of no
	     * value.  Take that away, and all this code is just a mildly
	     * optimized equivalent of a call to SetFsPathFromAny().  That
	     * optimization may have some value, *if* these value in fact
	     * get used as "path" values before used as something else.
	     * If not, though, whatever cost we pay below to convert to
	     * one of the "path" intreps is just a waste, it seems.  The
	     * usual convention in the core is to delay ObjType conversion
	     * until it is needed and demanded, and I don't see why this
	     * section of code should be an exception to that.  Leaving it
	     * in place for the rest of the 8.5.* releases just for sake
	     * of stability.
	     */

	    /*
	     * Free old representation.
	     */

	    if (pathPtr->typePtr != NULL) {
		if (pathPtr->bytes == NULL) {
		    if (pathPtr->typePtr->updateStringProc == NULL) {
			if (interp != NULL) {
			    Tcl_ResetResult(interp);
			    Tcl_AppendResult(interp, "can't find object"
				    "string representation", NULL);
			}
			return NULL;
		    }
		    pathPtr->typePtr->updateStringProc(pathPtr);
		}
		TclFreeIntRep(pathPtr);
	    }

	    /*
	     * Now pathPtr is a string object.
	     */

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

	    /*
	     * Circular reference, by design.
	     */

	    fsPathPtr->translatedPathPtr = pathPtr;
	    fsPathPtr->normPathPtr = NULL;
	    fsPathPtr->cwdPtr = cwdPtr;
	    Tcl_IncrRefCount(cwdPtr);
	    fsPathPtr->nativePathPtr = NULL;
	    fsPathPtr->fsPtr = NULL;
	    fsPathPtr->filesystemEpoch = 0;

	    SETPATHOBJ(pathPtr, fsPathPtr);
	    PATHFLAGS(pathPtr) = 0;
	    pathPtr->typePtr = &tclFsPathType;

	    return pathPtr;
	}
    }

    /*
     * 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.
     */

    tempStr = Tcl_GetStringFromObj(cwdPtr, &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 (tempStr[cwdLen-1] != '/') {
	    cwdLen++;
	}
	break;
    case TCL_PLATFORM_WINDOWS:
	if (tempStr[cwdLen-1] != '/' && tempStr[cwdLen-1] != '\\') {
	    cwdLen++;
	}
	break;
    }
    tempStr = Tcl_GetStringFromObj(pathPtr, &len);

    return Tcl_NewStringObj(tempStr + cwdLen, len - cwdLen);
}

/*
 *---------------------------------------------------------------------------
 *
 * MakePathFromNormalized --
 *
 *	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 int
MakePathFromNormalized(
    Tcl_Interp *interp,		/* Used for error reporting if not NULL. */
    Tcl_Obj *pathPtr)		/* The object to convert. */
{
    FsPath *fsPathPtr;

    if (pathPtr->typePtr == &tclFsPathType) {
	return TCL_OK;
    }

    /*
     * Free old representation
     */

    if (pathPtr->typePtr != NULL) {
	if (pathPtr->bytes == NULL) {
	    if (pathPtr->typePtr->updateStringProc == NULL) {
		if (interp != NULL) {
		    Tcl_ResetResult(interp);
		    Tcl_AppendResult(interp, "can't find object"
			    "string representation", NULL);
		}
		return TCL_ERROR;
	    }
	    pathPtr->typePtr->updateStringProc(pathPtr);
	}
	TclFreeIntRep(pathPtr);
    }

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

    /*
     * It's a pure normalized absolute path.
     */

    fsPathPtr->translatedPathPtr = NULL;

    /*
     * Circular reference by design.
     */

    fsPathPtr->normPathPtr = pathPtr;
    fsPathPtr->cwdPtr = NULL;
    fsPathPtr->nativePathPtr = NULL;
    fsPathPtr->fsPtr = NULL;
    /* Remember the epoch under which we decided pathPtr was normalized */
    fsPathPtr->filesystemEpoch = TclFSEpoch();

    SETPATHOBJ(pathPtr, fsPathPtr);
    PATHFLAGS(pathPtr) = 0;
    pathPtr->typePtr = &tclFsPathType;

    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSNewNativePath --
 *
 *	This function performs the something like the 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_FSNewNativePath(
    Tcl_Filesystem *fromFilesystem,
    ClientData clientData)
{
    Tcl_Obj *pathPtr = NULL;
    FsPath *fsPathPtr;


    if (fromFilesystem->internalToNormalizedProc != NULL) {
	pathPtr = (*fromFilesystem->internalToNormalizedProc)(clientData);
    }
    if (pathPtr == NULL) {
	return NULL;
    }

    /*
     * Free old representation; shouldn't normally be any, but best to be
     * safe.
     */

    if (pathPtr->typePtr != NULL) {
	if (pathPtr->bytes == NULL) {
	    if (pathPtr->typePtr->updateStringProc == NULL) {
		return NULL;
	    }
	    pathPtr->typePtr->updateStringProc(pathPtr);
	}
	TclFreeIntRep(pathPtr);
    }

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

    fsPathPtr->translatedPathPtr = NULL;

    /*
     * Circular reference, by design.
     */

    fsPathPtr->normPathPtr = pathPtr;
    fsPathPtr->cwdPtr = NULL;
    fsPathPtr->nativePathPtr = clientData;
    fsPathPtr->fsPtr = fromFilesystem;
    fsPathPtr->filesystemEpoch = TclFSEpoch();

    SETPATHOBJ(pathPtr, fsPathPtr);
    PATHFLAGS(pathPtr) = 0;
    pathPtr->typePtr = &tclFsPathType;

    return pathPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * 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(
    Tcl_Interp *interp,
    Tcl_Obj *pathPtr)
{
    Tcl_Obj *retObj = NULL;
    FsPath *srcFsPathPtr;

    if (Tcl_FSConvertToPathType(interp, pathPtr) != TCL_OK) {
	return NULL;
    }
    srcFsPathPtr = PATHOBJ(pathPtr);
    if (srcFsPathPtr->translatedPathPtr == NULL) {
	if (PATHFLAGS(pathPtr) != 0) {
	    /*
	     * We lack a translated path result, but we have a directory
	     * (cwdPtr) and a tail (normPathPtr), and if we join the
	     * translated version of cwdPtr to normPathPtr, we'll get the
	     * translated result we need, and can store it for future use.
	     */

	    Tcl_Obj *translatedCwdPtr = Tcl_FSGetTranslatedPath(interp,
		    srcFsPathPtr->cwdPtr);
	    if (translatedCwdPtr == NULL) {
		return NULL;
	    }

	    retObj = Tcl_FSJoinToPath(translatedCwdPtr, 1,
		    &(srcFsPathPtr->normPathPtr));
	    srcFsPathPtr->translatedPathPtr = retObj;
	    if (translatedCwdPtr->typePtr == &tclFsPathType) {
		srcFsPathPtr->filesystemEpoch
			= PATHOBJ(translatedCwdPtr)->filesystemEpoch;
	    } else {
		srcFsPathPtr->filesystemEpoch = 0;
	    }
	    Tcl_IncrRefCount(retObj);
	    Tcl_DecrRefCount(translatedCwdPtr);
	} else {
	    /*
	     * 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.
	     */

	    retObj = srcFsPathPtr->normPathPtr;
	}
    } else {
	/*
	 * It is an ordinary path object.
	 */

	retObj = srcFsPathPtr->translatedPathPtr;
    }

    if (retObj != NULL) {
	Tcl_IncrRefCount(retObj);
    }
    return retObj;
}

/*
 *---------------------------------------------------------------------------
 *
 * 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(
    Tcl_Interp *interp,
    Tcl_Obj *pathPtr)
{
    Tcl_Obj *transPtr = Tcl_FSGetTranslatedPath(interp, pathPtr);

    if (transPtr != NULL) {
	int len;
	const char *orig = Tcl_GetStringFromObj(transPtr, &len);
	char *result = (char *) ckalloc((unsigned) len+1);

	memcpy(result, orig, (size_t) len+1);
	TclDecrRefCount(transPtr);
	return result;
    }

    return NULL;
}

/*
 *---------------------------------------------------------------------------
 *
 * 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.
 *
 *---------------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSGetNormalizedPath(
    Tcl_Interp *interp,
    Tcl_Obj *pathPtr)
{
    FsPath *fsPathPtr;

    if (Tcl_FSConvertToPathType(interp, pathPtr) != TCL_OK) {
	return NULL;
    }
    fsPathPtr = PATHOBJ(pathPtr);

    if (PATHFLAGS(pathPtr) != 0) {
	/*
	 * This is a special path object which is the result of something like
	 * 'file join'
	 */

	Tcl_Obj *dir, *copy;
	int tailLen, cwdLen, pathType;

	pathType = Tcl_FSGetPathType(fsPathPtr->cwdPtr);
	dir = Tcl_FSGetNormalizedPath(interp, fsPathPtr->cwdPtr);
	if (dir == NULL) {
	    return NULL;
	}
	/* TODO: Figure out why this is needed. */
	if (pathPtr->bytes == NULL) {
	    UpdateStringOfFsPath(pathPtr);
	}

	Tcl_GetStringFromObj(fsPathPtr->normPathPtr, &tailLen);
	if (tailLen) {
	    copy = AppendPath(dir, fsPathPtr->normPathPtr);
	} else {
	    copy = Tcl_DuplicateObj(dir);
	}
	Tcl_IncrRefCount(dir);
	Tcl_IncrRefCount(copy);

	/*
	 * We now own a reference on both 'dir' and 'copy'
	 */

	(void) Tcl_GetStringFromObj(dir, &cwdLen);
	cwdLen += (Tcl_GetString(copy)[cwdLen] == '/');

	/* Normalize the combined string. */

	if (PATHFLAGS(pathPtr) & TCLPATH_NEEDNORM) {
	    /*
	     * If the "tail" part has components (like /../) that cause
	     * the combined path to need more complete normalizing,
	     * call on the more powerful routine to accomplish that so
	     * we avoid [Bug 2385549] ...
	     */

	    Tcl_Obj *newCopy = TclFSNormalizeAbsolutePath(interp, copy);
	    Tcl_DecrRefCount(copy);
	    copy = newCopy;
	} else {
	    /*
	     * ... but in most cases where we join a trouble free tail
	     * to a normalized head, we can more efficiently normalize the
	     * combined path by passing over only the unnormalized tail
	     * portion.  When this is sufficient, prior developers claim
	     * this should 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.
	     */

	    TclFSNormalizeToUniquePath(interp, copy, cwdLen-1);
	}

	/* Now we need to construct the new path object. */

	if (pathType == TCL_PATH_RELATIVE) {
	    Tcl_Obj *origDir = fsPathPtr->cwdPtr;

	    /*
	     * NOTE: here we are (dangerously?) assuming that origDir points
	     * to a Tcl_Obj with Tcl_ObjType == &tclFsPathType .  The
	     *     pathType = Tcl_FSGetPathType(fsPathPtr->cwdPtr);
	     * above that set the pathType value should have established
	     * that, but it's far less clear on what basis we know there's
	     * been no shimmering since then.
	     */

	    FsPath *origDirFsPathPtr = PATHOBJ(origDir);

	    fsPathPtr->cwdPtr = origDirFsPathPtr->cwdPtr;
	    Tcl_IncrRefCount(fsPathPtr->cwdPtr);

	    TclDecrRefCount(fsPathPtr->normPathPtr);
	    fsPathPtr->normPathPtr = copy;

	    /*
	     * That's our reference to copy used.
	     */

	    TclDecrRefCount(dir);
	    TclDecrRefCount(origDir);
	} else {
	    TclDecrRefCount(fsPathPtr->cwdPtr);
	    fsPathPtr->cwdPtr = NULL;
	    TclDecrRefCount(fsPathPtr->normPathPtr);
	    fsPathPtr->normPathPtr = copy;

	    /*
	     * That's our reference to copy used.
	     */

	    TclDecrRefCount(dir);
	}
	PATHFLAGS(pathPtr) = 0;
    }

    /*
     * Ensure cwd hasn't changed.
     */

    if (fsPathPtr->cwdPtr != NULL) {
	if (!TclFSCwdPointerEquals(&fsPathPtr->cwdPtr)) {
	    if (pathPtr->bytes == NULL) {
		UpdateStringOfFsPath(pathPtr);
	    }
	    FreeFsPathInternalRep(pathPtr);
	    if (Tcl_ConvertToType(interp, pathPtr, &tclFsPathType) != TCL_OK) {
		return NULL;
	    }
	    fsPathPtr = PATHOBJ(pathPtr);
	} else if (fsPathPtr->normPathPtr == NULL) {
	    int cwdLen;
	    Tcl_Obj *copy;

	    copy = AppendPath(fsPathPtr->cwdPtr, pathPtr);

	    (void) Tcl_GetStringFromObj(fsPathPtr->cwdPtr, &cwdLen);
	    cwdLen += (Tcl_GetString(copy)[cwdLen] == '/');

	    /*
	     * Normalize the combined string, but only starting after the end
	     * of the previously normalized 'dir'. This should be much faster!
	     */

	    TclFSNormalizeToUniquePath(interp, copy, cwdLen-1);
	    fsPathPtr->normPathPtr = copy;
	    Tcl_IncrRefCount(fsPathPtr->normPathPtr);
	}
    }
    if (fsPathPtr->normPathPtr == NULL) {
	Tcl_Obj *useThisCwd = NULL;
	int pureNormalized = 1;

	/*
	 * Since normPathPtr is NULL, but this is a valid path object, we know
	 * that the translatedPathPtr cannot be NULL.
	 */

	Tcl_Obj *absolutePath = fsPathPtr->translatedPathPtr;
	const char *path = TclGetString(absolutePath);

	Tcl_IncrRefCount(absolutePath);

	/*
	 * 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 action, which
	 * might loop back through here.
	 */

	if (path[0] == '\0') {
	    /*
	     * Special handling for the empty string value.  This one is
	     * very weird with [file normalize {}] => {}.  (The reasoning
	     * supporting this is unknown to DGP, but he fears changing it.)
	     * Attempt here to keep the expectations of other parts of
	     * Tcl_Filesystem code about state of the FsPath fields satisfied.
	     *
	     * In particular, capture the cwd value and save so it can be
	     * stored in the cwdPtr field below.
	     */

	    useThisCwd = Tcl_FSGetCwd(interp);
	} else {
	    /*
	     * We don't ask for the type of 'pathPtr' here, because that is
	     * not correct for our purposes when we have a path like '~'. Tcl
	     * has a bit of a contradiction in that '~' paths are defined as
	     * 'absolute', but in reality can be just about anything,
	     * depending on how env(HOME) is set.
	     */

	    Tcl_PathType type = Tcl_FSGetPathType(absolutePath);

	    if (type == TCL_PATH_RELATIVE) {
		useThisCwd = Tcl_FSGetCwd(interp);

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

		pureNormalized = 0;
		Tcl_DecrRefCount(absolutePath);
		absolutePath = Tcl_FSJoinToPath(useThisCwd, 1, &absolutePath);
		Tcl_IncrRefCount(absolutePath);

		/*
		 * We have a refCount on the cwd.
		 */
#ifdef __WIN32__
	    } else if (type == TCL_PATH_VOLUME_RELATIVE) {
		/*
		 * Only Windows has volume-relative paths.
		 */

		Tcl_DecrRefCount(absolutePath);
		absolutePath = TclWinVolumeRelativeNormalize(interp,
			path, &useThisCwd);
		if (absolutePath == NULL) {
		    return NULL;
		}
		pureNormalized = 0;
#endif /* __WIN32__ */
	    }
	}

	/*
	 * Already has refCount incremented.
	 */

	fsPathPtr->normPathPtr = TclFSNormalizeAbsolutePath(interp,
		absolutePath);

	/*
	 * Check if path is pure normalized (this can only be the case if it
	 * is an absolute path).
	 */

	if (pureNormalized) {
	    if (!strcmp(TclGetString(fsPathPtr->normPathPtr),
		    TclGetString(pathPtr))) {
		/*
		 * The path was already normalized. Get rid of the duplicate.
		 */

		TclDecrRefCount(fsPathPtr->normPathPtr);

		/*
		 * We do *not* increment the refCount for this circular
		 * reference.
		 */

		fsPathPtr->normPathPtr = pathPtr;
	    }
	}
	if (useThisCwd != NULL) {
	    /*
	     * We just need to free an object we allocated above for relative
	     * paths (this was returned by Tcl_FSJoinToPath above), and then
	     * of course store the cwd.
	     */

	    fsPathPtr->cwdPtr = useThisCwd;
	}
	TclDecrRefCount(absolutePath);
    }

    return fsPathPtr->normPathPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * 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(
    Tcl_Obj *pathPtr,
    Tcl_Filesystem *fsPtr)
{
    FsPath *srcFsPathPtr;

    if (Tcl_FSConvertToPathType(NULL, pathPtr) != TCL_OK) {
	return NULL;
    }
    srcFsPathPtr = PATHOBJ(pathPtr);

    /*
     * 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->fsPtr == 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(pathPtr);

	/*
	 * 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 = PATHOBJ(pathPtr);
	if (srcFsPathPtr->fsPtr == NULL) {
	    return NULL;
	}
    }

    /*
     * 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.
     */

    if (fsPtr != srcFsPathPtr->fsPtr) {
	const Tcl_Filesystem *actualFs = Tcl_FSGetFileSystemForPath(pathPtr);

	if (actualFs == fsPtr) {
	    return Tcl_FSGetInternalRep(pathPtr, fsPtr);
	}
	return NULL;
    }

    if (srcFsPathPtr->nativePathPtr == NULL) {
	Tcl_FSCreateInternalRepProc *proc;
	char *nativePathPtr;

	proc = srcFsPathPtr->fsPtr->createInternalRepProc;
	if (proc == NULL) {
	    return NULL;
	}

	nativePathPtr = (*proc)(pathPtr);
	srcFsPathPtr = PATHOBJ(pathPtr);
	srcFsPathPtr->nativePathPtr = nativePathPtr;
    }

    return srcFsPathPtr->nativePathPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclFSEnsureEpochOk --
 *
 *	This will ensure the pathPtr is up to date and 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.
 *
 * Results:
 *	Standard Tcl return code.
 *
 * Side effects:
 *	An attempt may be made to convert the object.
 *
 *---------------------------------------------------------------------------
 */

int
TclFSEnsureEpochOk(
    Tcl_Obj *pathPtr,
    Tcl_Filesystem **fsPtrPtr)
{
    FsPath *srcFsPathPtr;

    if (pathPtr->typePtr != &tclFsPathType) {
	return TCL_OK;
    }

    srcFsPathPtr = PATHOBJ(pathPtr);

    /*
     * Check if the filesystem has changed in some way since this object's
     * internal representation was calculated.
     */

    if (!TclFSEpochOk(srcFsPathPtr->filesystemEpoch)) {
	/*
	 * We have to discard the stale representation and recalculate it.
	 */

	if (pathPtr->bytes == NULL) {
	    UpdateStringOfFsPath(pathPtr);
	}
	FreeFsPathInternalRep(pathPtr);
	if (SetFsPathFromAny(NULL, pathPtr) != TCL_OK) {
	    return TCL_ERROR;
	}
	srcFsPathPtr = PATHOBJ(pathPtr);
    }

    /*
     * Check whether the object is already assigned to a fs.
     */

    if (srcFsPathPtr->fsPtr != NULL) {
	*fsPtrPtr = srcFsPathPtr->fsPtr;
    }
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclFSSetPathDetails --
 *
 *	???
 *
 * Results:
 *	None
 *
 * Side effects:
 *	???
 *
 *---------------------------------------------------------------------------
 */

void
TclFSSetPathDetails(
    Tcl_Obj *pathPtr,
    Tcl_Filesystem *fsPtr,
    ClientData clientData)
{
    FsPath *srcFsPathPtr;

    /*
     * Make sure pathPtr is of the correct type.
     */

    if (pathPtr->typePtr != &tclFsPathType) {
	if (SetFsPathFromAny(NULL, pathPtr) != TCL_OK) {
	    return;
	}
    }

    srcFsPathPtr = PATHOBJ(pathPtr);
    srcFsPathPtr->fsPtr = fsPtr;
    srcFsPathPtr->nativePathPtr = clientData;
    srcFsPathPtr->filesystemEpoch = TclFSEpoch();
}

/*
 *---------------------------------------------------------------------------
 *
 * 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(
    Tcl_Obj *firstPtr,
    Tcl_Obj *secondPtr)
{
    char *firstStr, *secondStr;
    int firstLen, secondLen, tempErrno;

    if (firstPtr == secondPtr) {
	return 1;
    }

    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);
    return (firstLen == secondLen) && (strcmp(firstStr, secondStr) == 0);
}

/*
 *---------------------------------------------------------------------------
 *
 * 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(
    Tcl_Interp *interp,		/* Used for error reporting if not NULL. */
    Tcl_Obj *pathPtr)		/* The object to convert. */
{
    int len;
    FsPath *fsPathPtr;
    Tcl_Obj *transPtr;
    char *name;

    if (pathPtr->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 or Win (fCmd.test, fileName.test and
     * cmdAH.test exercise most of the code).
     */

    name = Tcl_GetStringFromObj(pathPtr, &len);

    /*
     * Handle tilde substitutions, if needed.
     */

    if (name[0] == '~') {
	char *expandedUser;
	Tcl_DString temp;
	int split;
	char 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", 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", 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.
		 */

		int objc;
		Tcl_Obj **objv;
		Tcl_Obj *parts = TclpNativeSplitPath(pathPtr, NULL);

		Tcl_ListObjGetElements(NULL, parts, &objc, &objv);

		/*
		 * Skip '~'. It's replaced by its expansion.
		 */

		objc--; objv++;
		while (objc--) {
		    TclpNativeJoinPath(transPtr, Tcl_GetString(*objv++));
		}
		TclDecrRefCount(parts);
	    } else {
		/*
		 * Simple case. "rest" is relative path. Just join it. The
		 * "rest" object will be freed when Tcl_FSJoinToPath returns
		 * (unless something else claims a refCount on it).
		 */

		Tcl_Obj *joined;
		Tcl_Obj *rest = Tcl_NewStringObj(name+split+1, -1);

		Tcl_IncrRefCount(transPtr);
		joined = Tcl_FSJoinToPath(transPtr, 1, &rest);
		TclDecrRefCount(transPtr);
		transPtr = joined;
	    }
	}
	Tcl_DStringFree(&temp);
    } else {
	/* Bug 3479689: protect 0-refcount pathPth from getting freed */
	pathPtr->refCount++;
	transPtr = Tcl_FSJoinToPath(pathPtr, 0, NULL);
	pathPtr->refCount--;
    }

    /*
     * 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(sizeof(FsPath));

    fsPathPtr->translatedPathPtr = transPtr;
    if (transPtr != pathPtr) {
	Tcl_IncrRefCount(fsPathPtr->translatedPathPtr);
	/* Redo translation when $env(HOME) changes */
	fsPathPtr->filesystemEpoch = TclFSEpoch();
    } else {
	fsPathPtr->filesystemEpoch = 0;
    }
    fsPathPtr->normPathPtr = NULL;
    fsPathPtr->cwdPtr = NULL;
    fsPathPtr->nativePathPtr = NULL;
    fsPathPtr->fsPtr = NULL;

    /*
     * Free old representation before installing our new one.
     */

    TclFreeIntRep(pathPtr);
    SETPATHOBJ(pathPtr, fsPathPtr);
    PATHFLAGS(pathPtr) = 0;
    pathPtr->typePtr = &tclFsPathType;
    return TCL_OK;
}

static void
FreeFsPathInternalRep(
    Tcl_Obj *pathPtr)		/* Path object with internal rep to free. */
{
    FsPath *fsPathPtr = PATHOBJ(pathPtr);

    if (fsPathPtr->translatedPathPtr != NULL) {
	if (fsPathPtr->translatedPathPtr != pathPtr) {
	    TclDecrRefCount(fsPathPtr->translatedPathPtr);
	}
    }
    if (fsPathPtr->normPathPtr != NULL) {
	if (fsPathPtr->normPathPtr != pathPtr) {
	    TclDecrRefCount(fsPathPtr->normPathPtr);
	}
	fsPathPtr->normPathPtr = NULL;
    }
    if (fsPathPtr->cwdPtr != NULL) {
	TclDecrRefCount(fsPathPtr->cwdPtr);
    }
    if (fsPathPtr->nativePathPtr != NULL && fsPathPtr->fsPtr != NULL) {
	Tcl_FSFreeInternalRepProc *freeProc =
		fsPathPtr->fsPtr->freeInternalRepProc;

	if (freeProc != NULL) {
	    (*freeProc)(fsPathPtr->nativePathPtr);
	    fsPathPtr->nativePathPtr = NULL;
	}
    }

    ckfree((char *) fsPathPtr);
    pathPtr->typePtr = NULL;
}

static void
DupFsPathInternalRep(
    Tcl_Obj *srcPtr,		/* Path obj with internal rep to copy. */
    Tcl_Obj *copyPtr)		/* Path obj with internal rep to set. */
{
    FsPath *srcFsPathPtr = PATHOBJ(srcPtr);
    FsPath *copyFsPathPtr = (FsPath *) ckalloc(sizeof(FsPath));

    SETPATHOBJ(copyPtr, copyFsPathPtr);

    if (srcFsPathPtr->translatedPathPtr == srcPtr) {
	/* Cycle in src -> make cycle in copy. */
	copyFsPathPtr->translatedPathPtr = copyPtr;
    } else {
	copyFsPathPtr->translatedPathPtr = srcFsPathPtr->translatedPathPtr;
	if (copyFsPathPtr->translatedPathPtr != NULL) {
	    Tcl_IncrRefCount(copyFsPathPtr->translatedPathPtr);
	}
    }

    if (srcFsPathPtr->normPathPtr == srcPtr) {
	/* Cycle in src -> make cycle in copy. */
	copyFsPathPtr->normPathPtr = copyPtr;
    } else {
	copyFsPathPtr->normPathPtr = srcFsPathPtr->normPathPtr;
	if (copyFsPathPtr->normPathPtr != NULL) {
	    Tcl_IncrRefCount(copyFsPathPtr->normPathPtr);
	}
    }

    copyFsPathPtr->cwdPtr = srcFsPathPtr->cwdPtr;
    if (copyFsPathPtr->cwdPtr != NULL) {
	Tcl_IncrRefCount(copyFsPathPtr->cwdPtr);
    }

    copyFsPathPtr->flags = srcFsPathPtr->flags;

    if (srcFsPathPtr->fsPtr != NULL
	    && srcFsPathPtr->nativePathPtr != NULL) {
	Tcl_FSDupInternalRepProc *dupProc =
		srcFsPathPtr->fsPtr->dupInternalRepProc;

	if (dupProc != NULL) {
	    copyFsPathPtr->nativePathPtr =
		    (*dupProc)(srcFsPathPtr->nativePathPtr);
	} else {
	    copyFsPathPtr->nativePathPtr = NULL;
	}
    } else {
	copyFsPathPtr->nativePathPtr = NULL;
    }
    copyFsPathPtr->fsPtr = srcFsPathPtr->fsPtr;
    copyFsPathPtr->filesystemEpoch = srcFsPathPtr->filesystemEpoch;

    copyPtr->typePtr = &tclFsPathType;
}

/*
 *---------------------------------------------------------------------------
 *
 * UpdateStringOfFsPath --
 *
 *	Gives an object a valid string rep.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Memory may be allocated.
 *
 *---------------------------------------------------------------------------
 */

static void
UpdateStringOfFsPath(
    register Tcl_Obj *pathPtr)	/* path obj with string rep to update. */
{
    FsPath *fsPathPtr = PATHOBJ(pathPtr);
    int cwdLen;
    Tcl_Obj *copy;

    if (PATHFLAGS(pathPtr) == 0 || fsPathPtr->cwdPtr == NULL) {
	Tcl_Panic("Called UpdateStringOfFsPath with invalid object");
    }

    copy = AppendPath(fsPathPtr->cwdPtr, fsPathPtr->normPathPtr);

    pathPtr->bytes = Tcl_GetStringFromObj(copy, &cwdLen);
    pathPtr->length = cwdLen;
    copy->bytes = tclEmptyStringRep;
    copy->length = 0;
    TclDecrRefCount(copy);
}

/*
 *---------------------------------------------------------------------------
 *
 * TclNativePathInFilesystem --
 *
 *	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.
 *
 *---------------------------------------------------------------------------
 */

int
TclNativePathInFilesystem(
    Tcl_Obj *pathPtr,
    ClientData *clientDataPtr)
{
    /*
     * A special case is required to handle the empty path "". This is a valid
     * path (i.e. the user should be able to do 'file exists ""' without
     * throwing an error), but equally the path doesn't exist. Those are the
     * semantics of Tcl (at present anyway), so we have to abide by them here.
     */

    if (pathPtr->typePtr == &tclFsPathType) {
	if (pathPtr->bytes != NULL && pathPtr->bytes[0] == '\0') {
	    /*
	     * We reject the empty path "".
	     */

	    return -1;
	}

	/*
	 * Otherwise there is no way this path can be empty.
	 */
    } else {
	/*
	 * It is somewhat unusual to reach this code path without the object
	 * being of tclFsPathType. However, we do our best to deal with the
	 * situation.
	 */

	int len;

	(void) Tcl_GetStringFromObj(pathPtr, &len);
	if (len == 0) {
	    /*
	     * We reject the empty path "".
	     */

	    return -1;
	}
    }

    /*
     * Path is of correct type, or is of non-zero length, so we accept it.
     */

    return TCL_OK;
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */