/*
	     * Copy 7bit characters, but skip null-bytes when we are in input
	     * mode, so that they get converted to 0xC080.
	     */

	    *dst++ = *src++;
	} else if ((UCHAR(*src) == 0xC0) && (src + 1 < srcEnd)
	    && (UCHAR(src[1]) == 0x80)
	    && (
		!(flags & TCL_ENCODING_MODIFIED)
		|| ((flags & TCL_ENCODING_STRICT) == TCL_ENCODING_STRICT)
	    ))
	{
	    /*
	     * If in input mode, and -strict is specified: This is an error.
	     */
	    if (flags & TCL_ENCODING_MODIFIED) {
		result = TCL_CONVERT_SYNTAX;
		break;
	    }

	     */

	    TclGetString(objPtr);
	}
    }

    if (GotFlag(statePtr, CHANNEL_ENCODING_ERROR)) {
	/* TODO: UpdateInterest not needed here? */
	UpdateInterest(chanPtr);

	Tcl_SetErrno(EILSEQ);
	return -1;
    }
    /*
     * Early out when next read will see eofchar.
     *
     * NOTE: See DoRead for argument that it's a bug (one we're keeping) to
     * have this escape before the one for zero-char read request.
     */

    if (GotFlag(statePtr, CHANNEL_STICKY_EOF)) {
	SetFlag(statePtr, CHANNEL_EOF);
	assert(statePtr->inputEncodingFlags & TCL_ENCODING_END);
	assert(!GotFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR));

	/* TODO: UpdateInterest not needed here? */
	UpdateInterest(chanPtr);
	return 0;
    }

    /*
     * Special handling for zero-char read request.
     */
    if (toRead == 0) {
	if (GotFlag(statePtr, CHANNEL_EOF)) {
	    statePtr->inputEncodingFlags |= TCL_ENCODING_START;
	}
	ResetFlag(statePtr, CHANNEL_BLOCKED|CHANNEL_EOF);
	statePtr->inputEncodingFlags &= ~TCL_ENCODING_END;
	/* TODO: UpdateInterest not needed here? */
	UpdateInterest(chanPtr);
	return 0;
    }

    /*
     * This operation should occur at the top of a channel stack.
     */

	    if (binaryMode) {
		copiedNow = ReadBytes(statePtr, objPtr, toRead);
	    } else {
		copiedNow = ReadChars(statePtr, objPtr, toRead, &factor);
	    }

	    /*
	     * Recycle current buffer if empty.
	     */

	    bufPtr = statePtr->inQueueHead;
	    if (IsBufferEmpty(bufPtr)) {
		ChannelBuffer *nextPtr = bufPtr->nextPtr;

		RecycleBuffer(statePtr, bufPtr, 0);
		statePtr->inQueueHead = nextPtr;
		if (nextPtr == NULL) {
		    statePtr->inQueueTail = NULL;
		}
	    }

	    /*
	     * If CHANNEL_ENCODING_ERROR and CHANNEL_STICKY_EOF are both set,
	     * then CHANNEL_ENCODING_ERROR was caused by data that occurred
	     * after the EOF character was encountered, so it doesn't count as
	     * a real error.
	     */

	    if (GotFlag(statePtr, CHANNEL_ENCODING_ERROR)
		    && !GotFlag(statePtr, CHANNEL_STICKY_EOF)
		    && !GotFlag(statePtr, CHANNEL_NONBLOCKING)) {
		/* Channel is synchronous.  Return an error so that callers
		 * like [read] can return an error.
		*/
		Tcl_SetErrno(EILSEQ);
		copied = -1;
		goto finish;
	    }
	}

	if (copiedNow < 0) {
	    if (GotFlag(statePtr, CHANNEL_EOF)) {
		break;
	    }
	    if (GotFlag(statePtr, CHANNEL_NONBLOCKING|CHANNEL_BLOCKED)

	    }
	} else {
	    copied += copiedNow;
	    toRead -= copiedNow;
	}
    }

finish:
    /*
     * Failure to fill a channel buffer may have left channel reporting a
     * "blocked" state, but so long as we fulfilled the request here, the
     * caller does not consider us blocked.
     */

    if (toRead == 0) {

    *srcLenPtr = srcLen;

    if (srcStart + srcLen == eof) {
	/*
	 * EOF character was seen in EOL translated range. Leave current file
	 * position pointing at the EOF character, but don't store the EOF
	 * character in the output string.
	 *
	 * If CHANNEL_ENCODING_ERROR is set, it can only be because of data
	 * encountered after the EOF character, so it is nonsense.  Unset it.
	 */

	SetFlag(statePtr, CHANNEL_EOF | CHANNEL_STICKY_EOF);
	statePtr->inputEncodingFlags |= TCL_ENCODING_END;
	ResetFlag(statePtr, CHANNEL_BLOCKED|INPUT_SAW_CR|CHANNEL_ENCODING_ERROR);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_Ungets --

    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Channel chan;		/* The channel to read from. */
    int newline, i;		/* Discard newline at end? */
    int toRead;			/* How many bytes to read? */
    int charactersRead;		/* How many characters were read? */
    int mode;			/* Mode in which channel is opened. */
    Tcl_Obj *resultPtr, *returnOptsPtr, *chanObjPtr;

    if ((objc != 2) && (objc != 3)) {
	Interp *iPtr;

    argerror:
	iPtr = (Interp *) interp;
	Tcl_WrongNumArgs(interp, 1, objv, "channelId ?numChars?");

	 */

	if (!TclChanCaughtErrorBypass(interp, chan)) {
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "error reading \"%s\": %s",
		    TclGetString(chanObjPtr), Tcl_PosixError(interp)));
	}
	returnOptsPtr = Tcl_NewDictObj();
	Tcl_DictObjPut(NULL, returnOptsPtr, Tcl_NewStringObj("-result", -1)
	    , resultPtr);
	TclChannelRelease(chan);
	Tcl_DecrRefCount(resultPtr);
	Tcl_SetReturnOptions(interp, returnOptsPtr);
	return TCL_ERROR;
    }

    /*
     * If requested, remove the last newline in the channel if at EOF.
     */

    fconfigure $f -encoding binary
    # \x81 is invalid in utf-8
    puts -nonewline $f A\x81
    flush $f
    seek $f 0
    fconfigure $f -encoding utf-8 -buffering none -eofchar "" -translation lf -strictencoding 1
} -body {
    set status [catch {read $f} cres copts]
    set d [dict get $copts -result]
    binary scan $d H* hd


    lappend hd $status $cres
} -cleanup {
    close $f
    removeFile io-75.6
} -match glob -result {41 1 {error reading "*": illegal byte sequence}}

test io-75.7 {invalid utf-8 encoding eof handling (-strictencoding 1)} -setup {
    set fn [makeFile {} io-75.7]
    set f [open $fn w+]
    fconfigure $f -encoding binary
    # \xA1 is invalid in utf-8. -eofchar is not detected, because it comes later.
    puts -nonewline $f A\xA1\x1A
    flush $f
    seek $f 0
    fconfigure $f -encoding utf-8 -buffering none -eofchar \x1A -translation lf -strictencoding 1
} -body {
    set status [catch {read $f} cres copts]
    set d [dict get $copts -result]
    binary scan $d H* hd
    lappend hd [eof $f]
    lappend hd $status
    lappend hd $cres
    fconfigure $f -encoding iso8859-1
    lappend hd [read $f];# We changed encoding, so now we can read the \xA1
    close $f
    set hd
} -cleanup {
    removeFile io-75.7
} -match glob -result {41 0 1 {error reading "*": illegal byte sequence} ¡}

test io-75.8.incomplete {
    incomplete uft-8 char after eof char is not an error (-strictencoding 1)
} -setup {
    set hd {}
    set fn [makeFile {} io-75.8]
    set f [open $fn w+]
    fconfigure $f -encoding binary
    # \x81 is invalid and also incomplete utf-8 data, but because the eof
    # character \x1A appears first, it's not an error.
    puts -nonewline $f A\x1A\x81
    flush $f
    seek $f 0
    fconfigure $f -encoding utf-8 -buffering none -eofchar \x1A -translation lf -strictencoding 1
} -body {
    set d [read $f]
    binary scan $d H* hd
    lappend hd [eof $f]
    # there should be no error on additional reads
    lappend hd [read $f]
    close $f
    set hd
} -cleanup {
    removeFile io-75.8
} -result {41 1 {}}


test io-75.8.invalid {invalid utf-8 after eof char is not an error  (-strictencoding 1)} -setup {
    set res {}
    set fn [makeFile {} io-75.8]
    set f [open $fn w+]
    fconfigure $f -encoding binary
    # \xc0\x80 is invalid utf-8 data, but because the eof character \x1A
    # appears first, it's not an error.
    puts -nonewline $f A\x1a\xc0\x80
    flush $f
    seek $f 0
    fconfigure $f -encoding utf-8 -buffering none -eofchar \x1A -translation lf -strictencoding 1
} -body {
    set d [read $f]
    foreach char [split $d {}] {
	lappend res [format %x [scan $char %c]]
    }
    lappend res [eof $f]
    # there should be no error on additional reads
    lappend res [read $f]
    close $f
    set res
} -cleanup {
    removeFile io-75.8
} -result {41 1 {}}


test io-75.9 {unrepresentable character write passes and is replaced by ?} -setup {
    set fn [makeFile {} io-75.9]
    set f [open $fn w+]
    fconfigure $f -encoding iso8859-1 -strictencoding 1
} -body {
    catch {puts -nonewline $f "A\u2022"} msg

    # In shiftjis, \x81 starts a two-byte sequence.
    # But 2nd byte \xFF is not allowed
    puts -nonewline $f A\x81\xFFA
    flush $f
    seek $f 0
    fconfigure $f -encoding shiftjis -buffering none -eofchar "" -translation lf -strictencoding 1
} -body {
    set status [catch {read $f} cres copts]
    set d [dict get $copts -result]
    binary scan $d H* hd
    lappend hd $status
    lappend hd $cres
} -cleanup {
    close $f
    removeFile io-75.11
} -match glob -result {41 1 {error reading "*": illegal byte sequence}}

test io-75.12 {invalid utf-8 encoding read is ignored} -setup {
    set fn [makeFile {} io-75.12]

    fconfigure $f -encoding binary
    # \x81 is invalid in utf-8
    puts -nonewline $f "A\x81"
    flush $f
    seek $f 0
    fconfigure $f -encoding utf-8 -buffering none -eofchar "" -translation lf -strictencoding 1
} -body {
    set status [catch {read $f} cres copts]
    set d [dict get $copts -result]
    binary scan $d H* hd
    lappend hd $status
    close $f
    lappend hd $cres
} -cleanup {
    removeFile io-75.13
} -match glob -result {41 1 {error reading "*": illegal byte sequence}}

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