* The following structure is the internal rep for a ByteArray object. Keeps
 * track of how much memory has been used and how much has been allocated for
 * the byte array to enable growing and shrinking of the ByteArray object with
 * fewer mallocs.
 */

typedef struct ByteArray {
    int used;			/* The number of bytes used in the byte
    size_t used;			/* The number of bytes used in the byte
				 * array. */
    int allocated;		/* The amount of space actually allocated
    size_t allocated;		/* The amount of space actually allocated
				 * minus 1 byte. */
    unsigned char bytes[1];	/* The array of bytes. The actual size of this
				 * field depends on the 'allocated' field
				 * above. */
} ByteArray;

#define BYTEARRAY_SIZE(len) \
		((unsigned) (TclOffset(ByteArray, bytes) + (len)))
		((TclOffset(ByteArray, bytes) + (len)))
#define GET_BYTEARRAY(objPtr) \
		((ByteArray *) (objPtr)->internalRep.twoPtrValue.ptr1)
#define SET_BYTEARRAY(objPtr, baPtr) \
		(objPtr)->internalRep.twoPtrValue.ptr1 = (void *) (baPtr)

int
TclIsPureByteArray(

 */

void
Tcl_SetByteArrayObj(
    Tcl_Obj *objPtr,		/* Object to initialize as a ByteArray. */
    const unsigned char *bytes,	/* The array of bytes to use as the new
				   value. May be NULL even if length > 0. */
    int length)			/* Length of the array of bytes, which must
    size_t length)			/* Length of the array of bytes, which must
				   be >= 0. */
{
    ByteArray *byteArrayPtr;

    if (Tcl_IsShared(objPtr)) {
	Tcl_Panic("%s called with shared object", "Tcl_SetByteArrayObj");
    }

 *
 *----------------------------------------------------------------------
 */

unsigned char *
Tcl_SetByteArrayLength(
    Tcl_Obj *objPtr,		/* The ByteArray object. */
    int length)			/* New length for internal byte array. */
    size_t length)			/* New length for internal byte array. */
{
    ByteArray *byteArrayPtr;

    if (Tcl_IsShared(objPtr)) {
	Tcl_Panic("%s called with shared object", "Tcl_SetByteArrayLength");
    }
    if ((objPtr->typePtr != &properByteArrayType)

 */

static void
DupByteArrayInternalRep(
    Tcl_Obj *srcPtr,		/* Object with internal rep to copy. */
    Tcl_Obj *copyPtr)		/* Object with internal rep to set. */
{
    int length;
    size_t length;
    ByteArray *srcArrayPtr, *copyArrayPtr;

    srcArrayPtr = GET_BYTEARRAY(srcPtr);
    length = srcArrayPtr->used;

    copyArrayPtr = ckalloc(BYTEARRAY_SIZE(length));
    copyArrayPtr->used = length;
    copyArrayPtr->allocated = length;
    memcpy(copyArrayPtr->bytes, srcArrayPtr->bytes, (size_t) length);
    memcpy(copyArrayPtr->bytes, srcArrayPtr->bytes, length);
    SET_BYTEARRAY(copyPtr, copyArrayPtr);

    copyPtr->typePtr = srcPtr->typePtr;
}

/*
 *----------------------------------------------------------------------

 */

static void
UpdateStringOfByteArray(
    Tcl_Obj *objPtr)		/* ByteArray object whose string rep to
				 * update. */
{
    int i, length, size;
    size_t i, length, size;
    unsigned char *src;
    char *dst;
    ByteArray *byteArrayPtr;

    byteArrayPtr = GET_BYTEARRAY(objPtr);
    src = byteArrayPtr->bytes;
    length = byteArrayPtr->used;

    /*
     * How much space will string rep need?
     */

    size = length;
    for (i = 0; i < length && size >= 0; i++) {
    for (i = 0; (i < length) && (size != (size_t)-1); i++) {
	if ((src[i] == 0) || (src[i] > 127)) {
	    size++;
	}
    }
    if (size < 0) {
	Tcl_Panic("max size for a Tcl value (%d bytes) exceeded", INT_MAX);
    if (size == (size_t)-1) {
	Tcl_Panic("max size for a Tcl value exceeded");
    }

    dst = ckalloc(size + 1);
    objPtr->bytes = dst;
    objPtr->length = size;

    if (size == length) {
	memcpy(dst, src, (size_t) size);
	memcpy(dst, src, size);
	dst[size] = '\0';
    } else {
	for (i = 0; i < length; i++) {
	    dst += Tcl_UniCharToUtf(src[i], dst);
	}
	*dst = '\0';
    }

 *----------------------------------------------------------------------
 */

void
TclAppendBytesToByteArray(
    Tcl_Obj *objPtr,
    const unsigned char *bytes,
    int len)
    size_t len)
{
    ByteArray *byteArrayPtr;
    int needed;
    size_t needed;

    if (Tcl_IsShared(objPtr)) {
	Tcl_Panic("%s called with shared object","TclAppendBytesToByteArray");
    }
    if (len < 0) {
    if (len == (size_t)-1) {
	Tcl_Panic("%s must be called with definite number of bytes to append",
		"TclAppendBytesToByteArray");
    }
    if (len == 0) {
	/* Append zero bytes is a no-op. */
	return;
    }
    if ((objPtr->typePtr != &properByteArrayType)
	    && (objPtr->typePtr != &tclByteArrayType)) {
	SetByteArrayFromAny(NULL, objPtr);
    }
    byteArrayPtr = GET_BYTEARRAY(objPtr);

    if (len > INT_MAX - byteArrayPtr->used) {
	Tcl_Panic("max size for a Tcl value (%d bytes) exceeded", INT_MAX);
    if (len + byteArrayPtr->used > UINT_MAX) {
	Tcl_Panic("max size for a Tcl value (%u bytes) exceeded", UINT_MAX);
    }

    needed = byteArrayPtr->used + len;
    /*
     * If we need to, resize the allocated space in the byte array.
     */