More preparation for TIP #494 compatibitly. Add 2 utility functions, which can retreive big strings and ByteArrays without length overflow.

32 files changed, 197 insertions, 151 deletions

diff --git a/generic/tkCanvText.c b/generic/tkCanvText.c
index eb8dfe3..7c088b5 100644
--- a/generic/tkCanvText.c
+++ b/generic/tkCanvText.c
@@ -1006,12 +1006,13 @@ TextInsert(
     Tcl_Obj *obj)		/* New characters to be inserted. */
 {
     TextItem *textPtr = (TextItem *) itemPtr;
-    int byteIndex, byteCount, charsAdded;
+    int byteIndex, charsAdded;
+    size_t byteCount;
     char *newStr, *text;
     const char *string;
     Tk_CanvasTextInfo *textInfoPtr = textPtr->textInfoPtr;
 
-    string = Tcl_GetStringFromObj(obj, &byteCount);
+    string = TkGetStringFromObj(obj, &byteCount);
 
     text = textPtr->text;
 
@@ -1343,11 +1344,11 @@ GetTextIndex(
 				 * index. */
 {
     TextItem *textPtr = (TextItem *) itemPtr;
-    int length;
+    size_t length;
     int c;
     TkCanvas *canvasPtr = (TkCanvas *) canvas;
     Tk_CanvasTextInfo *textInfoPtr = textPtr->textInfoPtr;
-    const char *string = Tcl_GetStringFromObj(obj, &length);
+    const char *string = TkGetStringFromObj(obj, &length);
 
     c = string[0];
 
diff --git a/generic/tkCanvas.c b/generic/tkCanvas.c
index 680b8b2..64e0f5d 100644
--- a/generic/tkCanvas.c
+++ b/generic/tkCanvas.c
@@ -1252,8 +1252,7 @@ CanvasWidgetCmd(
 	    result = TCL_ERROR;
 	    goto done;
 	}
-	arg = Tcl_GetString(objv[2]);
-	length = objv[2]->length;
+	arg = TkGetStringFromObj(objv[2], &length);
 	c = arg[0];
 
 	/*
diff --git a/generic/tkClipboard.c b/generic/tkClipboard.c
index b902625..aa6bb93 100644
--- a/generic/tkClipboard.c
+++ b/generic/tkClipboard.c
@@ -449,10 +449,11 @@ Tk_ClipboardObjCmd(
 	    "-displayof", "-format", "-type", NULL
 	};
 	enum appendOptions { APPEND_DISPLAYOF, APPEND_FORMAT, APPEND_TYPE };
-	int subIndex, length;
+	int subIndex;
+	size_t length;
 
 	for (i = 2; i < objc - 1; i++) {
-	    string = Tcl_GetStringFromObj(objv[i], &length);
+	    string = TkGetStringFromObj(objv[i], &length);
 	    if (string[0] != '-') {
 		break;
 	    }
diff --git a/generic/tkCmds.c b/generic/tkCmds.c
index 434772b..81bb335 100644
--- a/generic/tkCmds.c
+++ b/generic/tkCmds.c
@@ -2071,13 +2071,14 @@ TkGetDisplayOf(
 				 * present. */
 {
     const char *string;
+    size_t length;
 
     if (objc < 1) {
 	return 0;
     }
-    string = Tcl_GetString(objv[0]);
-    if ((objv[0]->length >= 2) &&
-	    (strncmp(string, "-displayof", objv[0]->length) == 0)) {
+    string = TkGetStringFromObj(objv[0], &length);
+    if ((length >= 2) &&
+	    (strncmp(string, "-displayof", length) == 0)) {
         if (objc < 2) {
 	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "value for \"-displayof\" missing", -1));
diff --git a/generic/tkConfig.c b/generic/tkConfig.c
index 62b0857..4e90fab 100644
--- a/generic/tkConfig.c
+++ b/generic/tkConfig.c
@@ -656,14 +656,14 @@ DoObjConfig(
     case TK_OPTION_STRING: {
 	char *newStr;
 	const char *value;
-	int length;
+	size_t length;
 
 	if (nullOK && ObjectIsEmpty(valuePtr)) {
 	    valuePtr = NULL;
 	}
 	if (internalPtr != NULL) {
 	    if (valuePtr != NULL) {
-		value = Tcl_GetStringFromObj(valuePtr, &length);
+		value = TkGetStringFromObj(valuePtr, &length);
 		newStr = ckalloc(length + 1);
 		strcpy(newStr, value);
 	    } else {
diff --git a/generic/tkEntry.c b/generic/tkEntry.c
index 1ab5477..018380d 100644
--- a/generic/tkEntry.c
+++ b/generic/tkEntry.c
@@ -4386,16 +4386,17 @@ SpinboxInvoke(
 		 * there. If not, move to the first element of the list.
 		 */
 
-		int i, listc, elemLen, length = entryPtr->numChars;
+		int i, listc;
+		size_t elemLen, length = entryPtr->numChars;
 		const char *bytes;
 		Tcl_Obj **listv;
 
 		Tcl_ListObjGetElements(interp, sbPtr->listObj, &listc, &listv);
 		for (i = 0; i < listc; i++) {
-		    bytes = Tcl_GetStringFromObj(listv[i], &elemLen);
+		    bytes = TkGetStringFromObj(listv[i], &elemLen);
 		    if ((length == elemLen) &&
 			    (memcmp(bytes, entryPtr->string,
-				    (size_t) length) == 0)) {
+				    length) == 0)) {
 			sbPtr->eIndex = i;
 			break;
 		    }
diff --git a/generic/tkFont.c b/generic/tkFont.c
index 834e944..9f2fa11 100644
--- a/generic/tkFont.c
+++ b/generic/tkFont.c
@@ -712,7 +712,8 @@ Tk_FontObjCmd(
     case FONT_MEASURE: {
 	const char *string;
 	Tk_Font tkfont;
-	int length = 0, skip = 0;
+	size_t length = 0;
+	int skip = 0;
 
 	if (objc > 4) {
 	    skip = TkGetDisplayOf(interp, objc - 3, objv + 3, &tkwin);
@@ -729,7 +730,7 @@ Tk_FontObjCmd(
 	if (tkfont == NULL) {
 	    return TCL_ERROR;
 	}
-	string = Tcl_GetStringFromObj(objv[3 + skip], &length);
+	string = TkGetStringFromObj(objv[3 + skip], &length);
 	Tcl_SetObjResult(interp, Tcl_NewIntObj(
 		Tk_TextWidth(tkfont, string, length)));
 	Tk_FreeFont(tkfont);
@@ -3245,7 +3246,8 @@ Tk_TextLayoutToPostscript(
     LayoutChunk *chunkPtr = layoutPtr->chunks;
     int baseline = chunkPtr->y;
     Tcl_Obj *psObj = Tcl_NewObj();
-    int i, j, len;
+    int i, j;
+    size_t len;
     const char *p, *glyphname;
     char uindex[5], c, *ps;
     int ch;
@@ -3303,7 +3305,7 @@ Tk_TextLayoutToPostscript(
 	    sprintf(uindex, "%04X", ch);		/* endianness? */
 	    glyphname = Tcl_GetVar2(interp, "::tk::psglyphs", uindex, 0);
 	    if (glyphname) {
-		ps = Tcl_GetStringFromObj(psObj, &len);
+		ps = TkGetStringFromObj(psObj, &len);
 		if (ps[len-1] == '(') {
 		    /*
 		     * In-place edit. Ewww!
diff --git a/generic/tkFrame.c b/generic/tkFrame.c
index 0f1a1b3..e2aee37 100644
--- a/generic/tkFrame.c
+++ b/generic/tkFrame.c
@@ -488,7 +488,8 @@ CreateFrame(
     Tk_Window newWin;
     const char *className, *screenName, *visualName, *colormapName;
     const char *arg, *useOption;
-    int i, length, depth;
+    int i, depth;
+    size_t length;
     unsigned int mask;
     Colormap colormap;
     Visual *visual;
@@ -515,24 +516,24 @@ CreateFrame(
     className = colormapName = screenName = visualName = useOption = NULL;
     colormap = None;
     for (i = 2; i < objc; i += 2) {
-	arg = Tcl_GetStringFromObj(objv[i], &length);
+	arg = TkGetStringFromObj(objv[i], &length);
 	if (length < 2) {
 	    continue;
 	}
 	if ((arg[1] == 'c') && (length >= 3)
-		&& (strncmp(arg, "-class", (unsigned) length) == 0)) {
+		&& (strncmp(arg, "-class", length) == 0)) {
 	    className = Tcl_GetString(objv[i+1]);
 	} else if ((arg[1] == 'c') && (length >= 3)
-		&& (strncmp(arg, "-colormap", (unsigned) length) == 0)) {
+		&& (strncmp(arg, "-colormap", length) == 0)) {
 	    colormapName = Tcl_GetString(objv[i+1]);
 	} else if ((arg[1] == 's') && (type == TYPE_TOPLEVEL)
-		&& (strncmp(arg, "-screen", (unsigned) length) == 0)) {
+		&& (strncmp(arg, "-screen", length) == 0)) {
 	    screenName = Tcl_GetString(objv[i+1]);
 	} else if ((arg[1] == 'u') && (type == TYPE_TOPLEVEL)
-		&& (strncmp(arg, "-use", (unsigned) length) == 0)) {
+		&& (strncmp(arg, "-use", length) == 0)) {
 	    useOption = Tcl_GetString(objv[i+1]);
 	} else if ((arg[1] == 'v')
-		&& (strncmp(arg, "-visual", (unsigned) length) == 0)) {
+		&& (strncmp(arg, "-visual", length) == 0)) {
 	    visualName = Tcl_GetString(objv[i+1]);
 	}
     }
@@ -743,7 +744,8 @@ FrameWidgetObjCmd(
     };
     register Frame *framePtr = clientData;
     int result = TCL_OK, index;
-    int c, i, length;
+    int c, i;
+    size_t length;
     Tcl_Obj *objPtr;
 
     if (objc < 2) {
@@ -787,7 +789,7 @@ FrameWidgetObjCmd(
 	     */
 
 	    for (i = 2; i < objc; i++) {
-		const char *arg = Tcl_GetStringFromObj(objv[i], &length);
+		const char *arg = TkGetStringFromObj(objv[i], &length);
 
 		if (length < 2) {
 		    continue;
diff --git a/generic/tkGrab.c b/generic/tkGrab.c
index 00d4511..c37b6be 100644
--- a/generic/tkGrab.c
+++ b/generic/tkGrab.c
@@ -190,7 +190,7 @@ Tk_GrabObjCmd(
     TkDisplay *dispPtr;
     const char *arg;
     int index;
-    int len;
+    size_t len;
     static const char *const optionStrings[] = {
 	"current", "release", "set", "status", NULL
     };
@@ -227,7 +227,7 @@ Tk_GrabObjCmd(
      * First check for a window name or "-global" as the first argument.
      */
 
-    arg = Tcl_GetStringFromObj(objv[1], &len);
+    arg = TkGetStringFromObj(objv[1], &len);
     if (arg[0] == '.') {
 	/* [grab window] */
 	if (objc != 2) {
diff --git a/generic/tkGrid.c b/generic/tkGrid.c
index 20e66b6..aaed30f 100644
--- a/generic/tkGrid.c
+++ b/generic/tkGrid.c
@@ -2965,10 +2965,10 @@ ConfigureSlaves(
 
     firstChar = 0;
     for (numWindows=0, i=0; i < objc; i++) {
-	int length;
+	size_t length;
 	char prevChar = firstChar;
 
-	string = Tcl_GetStringFromObj(objv[i], &length);
+	string = TkGetStringFromObj(objv[i], &length);
     	firstChar = string[0];
 
 	if (firstChar == '.') {
diff --git a/generic/tkImgGIF.c b/generic/tkImgGIF.c
index b7bcd81..aacde56 100644
--- a/generic/tkImgGIF.c
+++ b/generic/tkImgGIF.c
@@ -757,10 +757,10 @@ StringMatchGIF(
     Tcl_Interp *interp)		/* not used */
 {
     unsigned char *data, header[10];
-    int got, length;
+    size_t got, length;
     MFile handle;
 
-    data = Tcl_GetByteArrayFromObj(dataObj, &length);
+    data = TkGetByteArrayFromObj(dataObj, &length);
 
     /*
      * Header is a minimum of 10 bytes.
@@ -826,9 +826,9 @@ StringReadGIF(
     int srcX, int srcY)
 {
     MFile handle, *hdlPtr = &handle;
-    int length;
+    size_t length;
     const char *xferFormat;
-    unsigned char *data = Tcl_GetByteArrayFromObj(dataObj, &length);
+    unsigned char *data = TkGetByteArrayFromObj(dataObj, &length);
 
     mInit(data, hdlPtr, length);
 
diff --git a/generic/tkImgListFormat.c b/generic/tkImgListFormat.c
index 1c3bff8..4636c41 100644
--- a/generic/tkImgListFormat.c
+++ b/generic/tkImgListFormat.c
@@ -772,13 +772,13 @@ ParseColor(
     unsigned char *alphaPtr)
 {
     const char *specString;
-    int charCount;
+    size_t charCount;
 
     /*
      * Find out which color format we have
      */
 
-    specString = Tcl_GetStringFromObj(specObj, &charCount);
+    specString = TkGetStringFromObj(specObj, &charCount);
 
     if (charCount == 0) {
         /* Empty string */
diff --git a/generic/tkImgPNG.c b/generic/tkImgPNG.c
index c985c92..52135ed 100644
--- a/generic/tkImgPNG.c
+++ b/generic/tkImgPNG.c
@@ -127,7 +127,7 @@ typedef struct {
     Tcl_Channel channel;	/* Channel for from-file reads. */
     Tcl_Obj *objDataPtr;
     unsigned char *strDataBuf;	/* Raw source data for from-string reads. */
-    int strDataLen;		/* Length of source data. */
+    size_t strDataLen;		/* Length of source data. */
     unsigned char *base64Data;	/* base64 encoded string data. */
     unsigned char base64Bits;	/* Remaining bits from last base64 read. */
     unsigned char base64State;	/* Current state of base64 decoder. */
@@ -215,16 +215,16 @@ static inline unsigned char Paeth(int a, int b, int c);
 static int		ParseFormat(Tcl_Interp *interp, Tcl_Obj *fmtObj,
 			    PNGImage *pngPtr);
 static int		ReadBase64(Tcl_Interp *interp, PNGImage *pngPtr,
-			    unsigned char *destPtr, int destSz,
+			    unsigned char *destPtr, size_t destSz,
 			    unsigned long *crcPtr);
 static int		ReadByteArray(Tcl_Interp *interp, PNGImage *pngPtr,
-			    unsigned char *destPtr, int destSz,
+			    unsigned char *destPtr, size_t destSz,
 			    unsigned long *crcPtr);
 static int		ReadData(Tcl_Interp *interp, PNGImage *pngPtr,
-			    unsigned char *destPtr, int destSz,
+			    unsigned char *destPtr, size_t destSz,
 			    unsigned long *crcPtr);
 static int		ReadChunkHeader(Tcl_Interp *interp, PNGImage *pngPtr,
-			    int *sizePtr, unsigned long *typePtr,
+			    size_t *sizePtr, unsigned long *typePtr,
 			    unsigned long *crcPtr);
 static int		ReadIDAT(Tcl_Interp *interp, PNGImage *pngPtr,
 			    int chunkSz, unsigned long crc);
@@ -251,9 +251,9 @@ static inline int	WriteByte(Tcl_Interp *interp, PNGImage *pngPtr,
 			    unsigned char c, unsigned long *crcPtr);
 static inline int	WriteChunk(Tcl_Interp *interp, PNGImage *pngPtr,
 			    unsigned long chunkType,
-			    const unsigned char *dataPtr, int dataSize);
+			    const unsigned char *dataPtr, size_t dataSize);
 static int		WriteData(Tcl_Interp *interp, PNGImage *pngPtr,
-			    const unsigned char *srcPtr, int srcSz,
+			    const unsigned char *srcPtr, size_t srcSz,
 			    unsigned long *crcPtr);
 static int		WriteExtraChunks(Tcl_Interp *interp,
 			    PNGImage *pngPtr);
@@ -320,7 +320,7 @@ InitPNGImage(
 	Tcl_IncrRefCount(objPtr);
 	pngPtr->objDataPtr = objPtr;
 	pngPtr->strDataBuf =
-		Tcl_GetByteArrayFromObj(objPtr, &pngPtr->strDataLen);
+		TkGetByteArrayFromObj(objPtr, &pngPtr->strDataLen);
     }
 
     /*
@@ -431,7 +431,7 @@ ReadBase64(
     Tcl_Interp *interp,
     PNGImage *pngPtr,
     unsigned char *destPtr,
-    int destSz,
+    size_t destSz,
     unsigned long *crcPtr)
 {
     static const unsigned char from64[] = {
@@ -556,14 +556,14 @@ ReadByteArray(
     Tcl_Interp *interp,
     PNGImage *pngPtr,
     unsigned char *destPtr,
-    int destSz,
+    size_t destSz,
     unsigned long *crcPtr)
 {
     /*
      * Check to make sure the number of requested bytes are available.
      */
 
-    if (pngPtr->strDataLen < destSz) {
+    if ((size_t)pngPtr->strDataLen < destSz) {
 	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"unexpected end of image data", -1));
 	Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "EARLY_END", NULL);
@@ -571,7 +571,7 @@ ReadByteArray(
     }
 
     while (destSz) {
-	int blockSz = PNG_MIN(destSz, PNG_BLOCK_SZ);
+	size_t blockSz = PNG_MIN(destSz, PNG_BLOCK_SZ);
 
 	memcpy(destPtr, pngPtr->strDataBuf, blockSz);
 
@@ -614,7 +614,7 @@ ReadData(
     Tcl_Interp *interp,
     PNGImage *pngPtr,
     unsigned char *destPtr,
-    int destSz,
+    size_t destSz,
     unsigned long *crcPtr)
 {
     if (pngPtr->base64Data) {
@@ -859,7 +859,7 @@ static int
 ReadChunkHeader(
     Tcl_Interp *interp,
     PNGImage *pngPtr,
-    int *sizePtr,
+    size_t *sizePtr,
     unsigned long *typePtr,
     unsigned long *crcPtr)
 {
@@ -1240,7 +1240,7 @@ ReadIHDR(
 {
     unsigned char sigBuf[PNG_SIG_SZ];
     unsigned long chunkType;
-    int chunkSz;
+    size_t chunkSz;
     unsigned long crc;
     unsigned long width, height;
     int mismatch;
@@ -1264,7 +1264,7 @@ ReadIHDR(
      */
 
     if (mismatch && pngPtr->strDataBuf) {
-	pngPtr->strDataBuf = Tcl_GetByteArrayFromObj(pngPtr->objDataPtr,
+	pngPtr->strDataBuf = TkGetByteArrayFromObj(pngPtr->objDataPtr,
 		&pngPtr->strDataLen);
 	pngPtr->base64Data = pngPtr->strDataBuf;
 
@@ -2098,7 +2098,7 @@ ReadIDAT(
      */
 
     while (chunkSz && !Tcl_ZlibStreamEof(pngPtr->stream)) {
-	int len1, len2;
+	size_t len1, len2;
 
 	/*
 	 * Read another block of input into the zlib stream if data remains.
@@ -2147,14 +2147,14 @@ ReadIDAT(
 	 */
 
     getNextLine:
-	Tcl_GetByteArrayFromObj(pngPtr->thisLineObj, &len1);
+	TkGetByteArrayFromObj(pngPtr->thisLineObj, &len1);
 	if (Tcl_ZlibStreamGet(pngPtr->stream, pngPtr->thisLineObj,
 		pngPtr->phaseSize - len1) == TCL_ERROR) {
 	    return TCL_ERROR;
 	}
-	Tcl_GetByteArrayFromObj(pngPtr->thisLineObj, &len2);
+	TkGetByteArrayFromObj(pngPtr->thisLineObj, &len2);
 
-	if (len2 == pngPtr->phaseSize) {
+	if (len2 == (size_t)pngPtr->phaseSize) {
 	    if (pngPtr->phase > 7) {
 		Tcl_SetObjResult(interp, Tcl_NewStringObj(
 			"extra data after final scan line of final phase",
@@ -2383,7 +2383,7 @@ DecodePNG(
     int destY)
 {
     unsigned long chunkType;
-    int chunkSz;
+    size_t chunkSz;
     unsigned long crc;
 
     /*
@@ -2768,7 +2768,7 @@ StringMatchPNG(
 
     InitPNGImage(NULL, &png, NULL, pObjData, TCL_ZLIB_STREAM_INFLATE);
 
-    png.strDataBuf = Tcl_GetByteArrayFromObj(pObjData, &png.strDataLen);
+    png.strDataBuf = TkGetByteArrayFromObj(pObjData, &png.strDataLen);
 
     if (ReadIHDR(interp, &png) == TCL_OK) {
 	*widthPtr = png.block.width;
@@ -2846,7 +2846,7 @@ WriteData(
     Tcl_Interp *interp,
     PNGImage *pngPtr,
     const unsigned char *srcPtr,
-    int srcSz,
+    size_t srcSz,
     unsigned long *crcPtr)
 {
     if (!srcPtr || !srcSz) {
@@ -2863,12 +2863,12 @@ WriteData(
      */
 
     if (pngPtr->objDataPtr) {
-	int objSz;
+	size_t objSz;
 	unsigned char *destPtr;
 
-	Tcl_GetByteArrayFromObj(pngPtr->objDataPtr, &objSz);
+	TkGetByteArrayFromObj(pngPtr->objDataPtr, &objSz);
 
-	if (objSz > INT_MAX - srcSz) {
+	if (objSz + srcSz > INT_MAX) {
 	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		    "image too large to store completely in byte array", -1));
 	    Tcl_SetErrorCode(interp, "TK", "IMAGE", "PNG", "TOO_LARGE", NULL);
@@ -2961,7 +2961,7 @@ WriteChunk(
     PNGImage *pngPtr,
     unsigned long chunkType,
     const unsigned char *dataPtr,
-    int dataSize)
+    size_t dataSize)
 {
     unsigned long crc = Tcl_ZlibCRC32(0, NULL, 0);
     int result = TCL_OK;
@@ -3132,9 +3132,10 @@ WriteIDAT(
     PNGImage *pngPtr,
     Tk_PhotoImageBlock *blockPtr)
 {
-    int rowNum, flush = TCL_ZLIB_NO_FLUSH, outputSize, result;
+    int rowNum, flush = TCL_ZLIB_NO_FLUSH, result;
     Tcl_Obj *outputObj;
     unsigned char *outputBytes;
+    size_t outputSize;    
 
     /*
      * Filter and compress each row one at a time.
@@ -3226,7 +3227,7 @@ WriteIDAT(
 
     outputObj = Tcl_NewObj();
     (void) Tcl_ZlibStreamGet(pngPtr->stream, outputObj, -1);
-    outputBytes = Tcl_GetByteArrayFromObj(outputObj, &outputSize);
+    outputBytes = TkGetByteArrayFromObj(outputObj, &outputSize);
     result = WriteChunk(interp, pngPtr, CHUNK_IDAT, outputBytes, outputSize);
     Tcl_DecrRefCount(outputObj);
     return result;
diff --git a/generic/tkImgPPM.c b/generic/tkImgPPM.c
index 6dd92a2..1cedc43 100644
--- a/generic/tkImgPPM.c
+++ b/generic/tkImgPPM.c
@@ -764,10 +764,11 @@ ReadPPMStringHeader(
 {
 #define BUFFER_SIZE 1000
     char buffer[BUFFER_SIZE], c;
-    int i, numFields, dataSize, type = 0;
+    int i, numFields, type = 0;
+    size_t dataSize;
     unsigned char *dataBuffer;
 
-    dataBuffer = Tcl_GetByteArrayFromObj(dataPtr, &dataSize);
+    dataBuffer = TkGetByteArrayFromObj(dataPtr, &dataSize);
 
     /*
      * Read 4 space-separated fields from the string, ignoring comments (any
diff --git a/generic/tkImgPhoto.c b/generic/tkImgPhoto.c
index fa58c86..e1d54dd 100644
--- a/generic/tkImgPhoto.c
+++ b/generic/tkImgPhoto.c
@@ -448,8 +448,7 @@ ImgPhotoCmd(
 	    Tcl_WrongNumArgs(interp, 2, objv, "option");
 	    return TCL_ERROR;
 	}
-	arg = Tcl_GetString(objv[2]);
-	length = objv[2]->length;
+	arg = TkGetStringFromObj(objv[2], &length);
 	if (strncmp(arg,"-data", length) == 0) {
 	    if (masterPtr->dataString) {
 		Tcl_SetObjResult(interp, masterPtr->dataString);
@@ -498,9 +497,8 @@ ImgPhotoCmd(
 	    return TCL_OK;
 
 	} else if (objc == 3) {
-	    const char *arg = Tcl_GetString(objv[2]);
+	    const char *arg = TkGetStringFromObj(objv[2], &length);
 
-	    length = objv[2]->length;
 	    if (length > 1 && !strncmp(arg, "-data", length)) {
 		Tcl_AppendResult(interp, "-data {} {} {}", NULL);
 		if (masterPtr->dataString) {
@@ -1491,8 +1489,7 @@ ParseSubcommandOptions(
 	 * optPtr->name.
 	 */
 
-	expandedOption = option = Tcl_GetString(objv[index]);
-	length = objv[index]->length;
+	expandedOption = option = TkGetStringFromObj(objv[index], &length);
 	if (option[0] != '-') {
 	    if (optPtr->name == NULL) {
 		optPtr->name = objv[index];
@@ -1770,8 +1767,7 @@ ImgPhotoConfigureMaster(
 
     args = ckalloc((objc + 1) * sizeof(char *));
     for (i = 0, j = 0; i < objc; i++,j++) {
-	args[j] = Tcl_GetString(objv[i]);
-	length = objv[i]->length;
+	args[j] = TkGetStringFromObj(objv[i], &length);
 	if ((length > 1) && (args[j][0] == '-')) {
 	    if ((args[j][1] == 'd') &&
 		    !strncmp(args[j], "-data", length)) {
@@ -1850,9 +1846,9 @@ ImgPhotoConfigureMaster(
 	 * Force into ByteArray format, which most (all) image handlers will
 	 * use anyway. Empty length means ignore the -data option.
 	 */
-	int bytesize;
+	size_t bytesize;
 
-	(void) Tcl_GetByteArrayFromObj(data, &bytesize);
+	(void) TkGetByteArrayFromObj(data, &bytesize);
 	if (bytesize) {
 	    Tcl_IncrRefCount(data);
 	} else {
diff --git a/generic/tkInt.h b/generic/tkInt.h
index d21b14f..62560bd 100644
--- a/generic/tkInt.h
+++ b/generic/tkInt.h
@@ -1242,13 +1242,21 @@ MODULE_SCOPE void	TkUnixSetXftClipRegion(TkRegion clipRegion);
 #endif
 
 #if TCL_UTF_MAX > 4
-#   define TkUtfToUniChar Tcl_UtfToUniChar
-#   define TkUniCharToUtf Tcl_UniCharToUtf
+#   define TkUtfToUniChar (size_t)Tcl_UtfToUniChar
+#   define TkUniCharToUtf (size_t)Tcl_UniCharToUtf
 #else
-    MODULE_SCOPE int TkUtfToUniChar(const char *, int *);
-    MODULE_SCOPE int TkUniCharToUtf(int, char *);
+    MODULE_SCOPE size_t TkUtfToUniChar(const char *, int *);
+    MODULE_SCOPE size_t TkUniCharToUtf(int, char *);
 #endif
 
+#define TkGetStringFromObj(objPtr, lenPtr) \
+    (((objPtr)->bytes \
+	    ? 0 : Tcl_GetString((objPtr)), \
+	    *(lenPtr) = (objPtr)->length, (objPtr)->bytes))
+
+MODULE_SCOPE unsigned char *TkGetByteArrayFromObj(Tcl_Obj *objPtr,
+	size_t *lengthPtr);
+
 /*
  * Unsupported commands.
  */
diff --git a/generic/tkListbox.c b/generic/tkListbox.c
index 5f650fe..1e5b92e 100644
--- a/generic/tkListbox.c
+++ b/generic/tkListbox.c
@@ -1102,7 +1102,8 @@ ListboxBboxSubCmd(
     if ((listPtr->topIndex <= index) && (index < lastVisibleIndex)) {
 	Tcl_Obj *el, *results[4];
 	const char *stringRep;
-	int pixelWidth, stringLen, x, y, result;
+	int pixelWidth, x, y, result;
+	size_t stringLen;
 	Tk_FontMetrics fm;
 
 	/*
@@ -1114,7 +1115,7 @@ ListboxBboxSubCmd(
 	    return result;
 	}
 
-	stringRep = Tcl_GetStringFromObj(el, &stringLen);
+	stringRep = TkGetStringFromObj(el, &stringLen);
 	Tk_GetFontMetrics(listPtr->tkfont, &fm);
 	pixelWidth = Tk_TextWidth(listPtr->tkfont, stringRep, stringLen);
 
@@ -1840,7 +1841,8 @@ DisplayListbox(
     register Listbox *listPtr = clientData;
     register Tk_Window tkwin = listPtr->tkwin;
     GC gc;
-    int i, limit, x, y, prevSelected, freeGC, stringLen;
+    int i, limit, x, y, prevSelected, freeGC;
+    size_t stringLen;
     Tk_FontMetrics fm;
     Tcl_Obj *curElement;
     Tcl_HashEntry *entry;
@@ -2074,7 +2076,7 @@ DisplayListbox(
 	 */
 
         Tcl_ListObjIndex(listPtr->interp, listPtr->listObj, i, &curElement);
-        stringRep = Tcl_GetStringFromObj(curElement, &stringLen);
+        stringRep = TkGetStringFromObj(curElement, &stringLen);
         textWidth = Tk_TextWidth(listPtr->tkfont, stringRep, stringLen);
 
 	Tk_GetFontMetrics(listPtr->tkfont, &fm);
@@ -2236,7 +2238,8 @@ ListboxComputeGeometry(
 				 * Tk_UnsetGrid to update gridding for the
 				 * window. */
 {
-    int width, height, pixelWidth, pixelHeight, textLength, i, result;
+    int width, height, pixelWidth, pixelHeight, i, result;
+    size_t textLength;
     Tk_FontMetrics fm;
     Tcl_Obj *element;
     const char *text;
@@ -2257,7 +2260,7 @@ ListboxComputeGeometry(
 	    if (result != TCL_OK) {
 		continue;
 	    }
-	    text = Tcl_GetStringFromObj(element, &textLength);
+	    text = TkGetStringFromObj(element, &textLength);
 	    Tk_GetFontMetrics(listPtr->tkfont, &fm);
 	    pixelWidth = Tk_TextWidth(listPtr->tkfont, text, textLength);
 	    if (pixelWidth > listPtr->maxWidth) {
@@ -2323,7 +2326,8 @@ ListboxInsertSubCmd(
     int objc,			/* Number of new elements to add. */
     Tcl_Obj *const objv[])	/* New elements (one per entry). */
 {
-    int i, oldMaxWidth, pixelWidth, result, length;
+    int i, oldMaxWidth, pixelWidth, result;
+    size_t length;
     Tcl_Obj *newListObj;
     const char *stringRep;
 
@@ -2334,7 +2338,7 @@ ListboxInsertSubCmd(
 	 * if so, update our notion of "widest."
 	 */
 
-	stringRep = Tcl_GetStringFromObj(objv[i], &length);
+	stringRep = TkGetStringFromObj(objv[i], &length);
 	pixelWidth = Tk_TextWidth(listPtr->tkfont, stringRep, length);
 	if (pixelWidth > listPtr->maxWidth) {
 	    listPtr->maxWidth = pixelWidth;
@@ -2437,7 +2441,8 @@ ListboxDeleteSubCmd(
     int first,			/* Index of first element to delete. */
     int last)			/* Index of last element to delete. */
 {
-    int count, i, widthChanged, length, result, pixelWidth;
+    int count, i, widthChanged, result, pixelWidth;
+    size_t length;
     Tcl_Obj *newListObj, *element;
     const char *stringRep;
     Tcl_HashEntry *entry;
@@ -2492,7 +2497,7 @@ ListboxDeleteSubCmd(
 
 	if (widthChanged == 0) {
 	    Tcl_ListObjIndex(listPtr->interp, listPtr->listObj, i, &element);
-	    stringRep = Tcl_GetStringFromObj(element, &length);
+	    stringRep = TkGetStringFromObj(element, &length);
 	    pixelWidth = Tk_TextWidth(listPtr->tkfont, stringRep, length);
 	    if (pixelWidth == listPtr->maxWidth) {
 		widthChanged = 1;
@@ -3122,7 +3127,8 @@ ListboxFetchSelection(
 {
     register Listbox *listPtr = clientData;
     Tcl_DString selection;
-    int length, count, needNewline, stringLen, i;
+    int count, needNewline, i;
+    size_t length, stringLen;
     Tcl_Obj *curElement;
     const char *stringRep;
     Tcl_HashEntry *entry;
@@ -3145,7 +3151,7 @@ ListboxFetchSelection(
 	    }
 	    Tcl_ListObjIndex(listPtr->interp, listPtr->listObj, i,
 		    &curElement);
-	    stringRep = Tcl_GetStringFromObj(curElement, &stringLen);
+	    stringRep = TkGetStringFromObj(curElement, &stringLen);
 	    Tcl_DStringAppend(&selection, stringRep, stringLen);
 	    needNewline = 1;
 	}
diff --git a/generic/tkMenu.c b/generic/tkMenu.c
index 7b06035..7441ca2 100644
--- a/generic/tkMenu.c
+++ b/generic/tkMenu.c
@@ -1700,12 +1700,12 @@ PostProcessEntry(
     if (mePtr->labelPtr == NULL) {
 	mePtr->labelLength = 0;
     } else {
-	Tcl_GetStringFromObj(mePtr->labelPtr, &mePtr->labelLength);
+	(void)TkGetStringFromObj(mePtr->labelPtr, &mePtr->labelLength);
     }
     if (mePtr->accelPtr == NULL) {
 	mePtr->accelLength = 0;
     } else {
-	Tcl_GetStringFromObj(mePtr->accelPtr, &mePtr->accelLength);
+	(void)TkGetStringFromObj(mePtr->accelPtr, &mePtr->accelLength);
     }
 
     /*
diff --git a/generic/tkMenu.h b/generic/tkMenu.h
index bac51aa..b4269a5 100644
--- a/generic/tkMenu.h
+++ b/generic/tkMenu.h
@@ -68,11 +68,15 @@ typedef struct TkMenuEntry {
     Tk_OptionTable optionTable;	/* Option table for this menu entry. */
     Tcl_Obj *labelPtr;		/* Main text label displayed in entry (NULL if
 				 * no label). */
-    int labelLength;		/* Number of non-NULL characters in label. */
+#if TK_MAJOR_VERSION > 8
+    size_t labelLength;		/* Number of non-NULL characters in label. */
+#else
+    unsigned int labelLength;		/* Number of non-NULL characters in label. */
+#endif
     int state;			/* State of button for display purposes:
 				 * normal, active, or disabled. */
     int underline;		/* Value of -underline option: specifies index
-				 * of character to underline (<0 means don't
+				 * of character to underline (-1 means don't
 				 * underline anything). */
     Tcl_Obj *underlinePtr;	/* Index of character to underline. */
     Tcl_Obj *bitmapPtr;		/* Bitmap to display in menu entry, or None.
@@ -89,8 +93,13 @@ typedef struct TkMenuEntry {
     Tcl_Obj *accelPtr;		/* Accelerator string displayed at right of
 				 * menu entry. NULL means no such accelerator.
 				 * Malloc'ed. */
-    int accelLength;		/* Number of non-NULL characters in
+#if TK_MAJOR_VERSION > 8
+    size_t accelLength;		/* Number of non-NULL characters in
+				 * accelerator. */
+#else
+    unsigned int accelLength;		/* Number of non-NULL characters in
 				 * accelerator. */
+#endif
     int indicatorOn;		/* True means draw indicator, false means
 				 * don't draw it. This field is ignored unless
 				 * the entry is a radio or check button. */
diff --git a/generic/tkPack.c b/generic/tkPack.c
index bee38d5..d7fabca 100644
--- a/generic/tkPack.c
+++ b/generic/tkPack.c
@@ -1181,8 +1181,8 @@ PackAfter(
 	packPtr->flags |= OLD_STYLE;
 	for (index = 0 ; index < optionCount; index++) {
 	    Tcl_Obj *curOptPtr = options[index];
-	    const char *curOpt = Tcl_GetString(curOptPtr);
-	    size_t length = curOptPtr->length;
+	    size_t length;
+	    const char *curOpt = TkGetStringFromObj(curOptPtr, &length);
 
 	    c = curOpt[0];
 
diff --git a/generic/tkScale.c b/generic/tkScale.c
index af45afa..1c65001 100644
--- a/generic/tkScale.c
+++ b/generic/tkScale.c
@@ -638,7 +638,7 @@ ConfigureScale(
 
 	ComputeFormat(scalePtr);
 
-	scalePtr->labelLength = scalePtr->label ? (int)strlen(scalePtr->label) : 0;
+	scalePtr->labelLength = scalePtr->label ? strlen(scalePtr->label) : 0;
 
 	Tk_SetBackgroundFromBorder(scalePtr->tkwin, scalePtr->bgBorder);
 
diff --git a/generic/tkScale.h b/generic/tkScale.h
index aa0feff..043d23c 100644
--- a/generic/tkScale.h
+++ b/generic/tkScale.h
@@ -85,7 +85,11 @@ typedef struct TkScale {
     int repeatInterval;		/* Interval between autorepeats (in ms). */
     char *label;		/* Label to display above or to right of
 				 * scale; NULL means don't display a label. */
-    int labelLength;		/* Number of non-NULL chars. in label. */
+#if TK_MAJOR_VERSION > 8
+    size_t labelLength;		/* Number of non-NULL chars. in label. */
+#else
+    unsigned int labelLength;		/* Number of non-NULL chars. in label. */
+#endif
     enum state state;		/* Values are active, normal, or disabled.
 				 * Value of scale cannot be changed when
 				 * disabled. */
diff --git a/generic/tkScrollbar.c b/generic/tkScrollbar.c
index 8ace793..02fb740 100644
--- a/generic/tkScrollbar.c
+++ b/generic/tkScrollbar.c
@@ -226,8 +226,8 @@ ScrollbarWidgetObjCmd(
     Tcl_Obj *const objv[])		/* Argument strings. */
 {
     register TkScrollbar *scrollPtr = clientData;
-    int result = TCL_OK;
-    int length, cmdIndex;
+    int result = TCL_OK, cmdIndex;
+    size_t length;
     static const char *const commandNames[] = {
         "activate", "cget", "configure", "delta", "fraction",
         "get", "identify", "set", NULL
@@ -271,7 +271,7 @@ ScrollbarWidgetObjCmd(
 		Tcl_WrongNumArgs(interp, 1, objv, "activate element");
 	    goto error;
 	}
-	c = Tcl_GetStringFromObj(objv[2], &length)[0];
+	c = TkGetStringFromObj(objv[2], &length)[0];
 	oldActiveField = scrollPtr->activeField;
 	if ((c == 'a') && (strcmp(Tcl_GetString(objv[2]), "arrow1") == 0)) {
 	    scrollPtr->activeField = TOP_ARROW;
diff --git a/generic/tkSelect.c b/generic/tkSelect.c
index 139ef3a..02268d3 100644
--- a/generic/tkSelect.c
+++ b/generic/tkSelect.c
@@ -831,7 +831,7 @@ Tk_SelectionObjCmd(
 	const char *targetName = NULL;
 	const char *formatName = NULL;
 	register CommandInfo *cmdInfoPtr;
-	int cmdLength;
+	size_t cmdLength;
 	static const char *const handleOptionStrings[] = {
 	    "-format", "-selection", "-type", NULL
 	};
@@ -900,7 +900,7 @@ Tk_SelectionObjCmd(
 	} else {
 	    format = XA_STRING;
 	}
-	string = Tcl_GetStringFromObj(objs[1], &cmdLength);
+	string = TkGetStringFromObj(objs[1], &cmdLength);
 	if (cmdLength == 0) {
 	    Tk_DeleteSelHandler(tkwin, selection, target);
 	} else {
diff --git a/generic/tkText.c b/generic/tkText.c
index b2bffbf..bc60e90 100644
--- a/generic/tkText.c
+++ b/generic/tkText.c
@@ -866,10 +866,9 @@ TextWidgetObjCmd(
 	for (i = 2; i < objc-2; i++) {
 	    int value;
 	    size_t length;
-	    const char *option = Tcl_GetString(objv[i]);
+	    const char *option = TkGetStringFromObj(objv[i], &length);
 	    char c;
 
-	    length = objv[i]->length;
 	    if (length < 2 || option[0] != '-') {
 		goto badOption;
 	    }
@@ -1277,14 +1276,12 @@ TextWidgetObjCmd(
 
 	i = 2;
 	if (objc > 3) {
-	    name = Tcl_GetString(objv[i]);
-	    length = objv[i]->length;
+	    name = TkGetStringFromObj(objv[i], &length);
 	    if (length > 1 && name[0] == '-') {
 		if (strncmp("-displaychars", name, length) == 0) {
 		    i++;
 		    visible = 1;
-		    name = Tcl_GetString(objv[i]);
-		    length = objv[i]->length;
+		    name = TkGetStringFromObj(objv[i], &length);
 		}
 		if ((i < objc-1) && (length == 2) && !strcmp("--", name)) {
 		    i++;
@@ -2640,9 +2637,8 @@ InsertChars(
     int *lineAndByteIndex;
     int resetViewCount;
     int pixels[2*PIXEL_CLIENTS];
-    const char *string = Tcl_GetString(stringPtr);
+    const char *string = TkGetStringFromObj(stringPtr, &length);
 
-    length = stringPtr->length;
     if (sharedTextPtr == NULL) {
 	sharedTextPtr = textPtr->sharedTextPtr;
     }
@@ -4764,8 +4760,7 @@ TextDumpCmd(
 	if (TkTextGetObjIndex(interp, textPtr, objv[arg], &index2) != TCL_OK) {
 	    return TCL_ERROR;
 	}
-	str = Tcl_GetString(objv[arg]);
-	length = objv[arg]->length;
+	str = TkGetStringFromObj(objv[arg], &length);
 	if (strncmp(str, "end", length) == 0) {
 	    atEnd = 1;
 	}
@@ -5838,8 +5833,7 @@ SearchCore(
 	 * it has dual purpose.
 	 */
 
-	pattern = Tcl_GetString(patObj);
-	matchLength = patObj->length;
+	pattern = Tcl_GetStringFromObj(patObj, &matchLength);
 	nl = strchr(pattern, '\n');
 
 	/*
diff --git a/generic/tkTextDisp.c b/generic/tkTextDisp.c
index 00c86b8..0764a87 100644
--- a/generic/tkTextDisp.c
+++ b/generic/tkTextDisp.c
@@ -6089,7 +6089,7 @@ TkTextYviewCmd(
     TextDInfo *dInfoPtr = textPtr->dInfoPtr;
     int pickPlace, type;
     int pixels, count;
-    int switchLength;
+    size_t switchLength;
     double fraction;
     TkTextIndex index;
 
@@ -6109,7 +6109,7 @@ TkTextYviewCmd(
     pickPlace = 0;
     if (Tcl_GetString(objv[2])[0] == '-') {
 	register const char *switchStr =
-		Tcl_GetStringFromObj(objv[2], &switchLength);
+		TkGetStringFromObj(objv[2], &switchLength);
 
 	if ((switchLength >= 2) && (strncmp(switchStr, "-pickplace",
 		(unsigned) switchLength) == 0)) {
diff --git a/generic/tkTextMark.c b/generic/tkTextMark.c
index 6a41c77..19d0c2a 100644
--- a/generic/tkTextMark.c
+++ b/generic/tkTextMark.c
@@ -126,14 +126,14 @@ TkTextMarkCmd(
     switch ((enum markOptions) optionIndex) {
     case MARK_GRAVITY: {
 	char c;
-	int length;
+	size_t length;
 	const char *str;
 
 	if (objc < 4 || objc > 5) {
 	    Tcl_WrongNumArgs(interp, 3, objv, "markName ?gravity?");
 	    return TCL_ERROR;
 	}
-	str = Tcl_GetStringFromObj(objv[3], &length);
+	str = TkGetStringFromObj(objv[3], &length);
 	if (length == 6 && !strcmp(str, "insert")) {
 	    markPtr = textPtr->insertMarkPtr;
 	} else if (length == 7 && !strcmp(str, "current")) {
@@ -160,7 +160,7 @@ TkTextMarkCmd(
 	    Tcl_SetObjResult(interp, Tcl_NewStringObj(typeStr, -1));
 	    return TCL_OK;
 	}
-	str = Tcl_GetStringFromObj(objv[4],&length);
+	str = TkGetStringFromObj(objv[4],&length);
 	c = str[0];
 	if ((c == 'l') && (strncmp(str, "left", (unsigned) length) == 0)) {
 	    newTypePtr = &tkTextLeftMarkType;
diff --git a/generic/tkTextTag.c b/generic/tkTextTag.c
index 9ade3ad..66f467b 100644
--- a/generic/tkTextTag.c
+++ b/generic/tkTextTag.c
@@ -1108,10 +1108,10 @@ FindTag(
     Tcl_Obj *tagName)		/* Name of desired tag. */
 {
     Tcl_HashEntry *hPtr;
-    int len;
+    size_t len;
     const char *str;
 
-    str = Tcl_GetStringFromObj(tagName, &len);
+    str = TkGetStringFromObj(tagName, &len);
     if (len == 3 && !strcmp(str, "sel")) {
 	return textPtr->selTagPtr;
     }
diff --git a/generic/tkUtil.c b/generic/tkUtil.c
index 1db7684..9f2dab1 100644
--- a/generic/tkUtil.c
+++ b/generic/tkUtil.c
@@ -729,8 +729,8 @@ Tk_GetScrollInfoObj(
     int *intPtr)		/* Filled in with number of pages or lines to
 				 * scroll, if any. */
 {
-    const char *arg = Tcl_GetString(objv[2]);
-    size_t length = objv[2]->length;
+    size_t length;
+    const char *arg = TkGetStringFromObj(objv[2], &length);
 
 #define ArgPfxEq(str) \
 	((arg[0] == str[0]) && !strncmp(arg, str, length))
@@ -753,8 +753,7 @@ Tk_GetScrollInfoObj(
 	    return TK_SCROLL_ERROR;
 	}
 
-	arg = Tcl_GetString(objv[4]);
-	length = objv[4]->length;
+	arg = TkGetStringFromObj(objv[4], &length);
 	if (ArgPfxEq("pages")) {
 	    return TK_SCROLL_PAGES;
 	} else if (ArgPfxEq("units")) {
@@ -1213,7 +1212,7 @@ TkSendVirtualEvent(
  *---------------------------------------------------------------------------
  */
 
-int
+size_t
 TkUtfToUniChar(
     const char *src,	/* The UTF-8 string. */
     int *chPtr)		/* Filled with the Tcl_UniChar represented by
@@ -1221,12 +1220,12 @@ TkUtfToUniChar(
 {
     Tcl_UniChar uniChar = 0;
 
-    int len = Tcl_UtfToUniChar(src, &uniChar);
+    size_t len = Tcl_UtfToUniChar(src, &uniChar);
     if ((uniChar & 0xfc00) == 0xd800) {
 	Tcl_UniChar high = uniChar;
 	/* This can only happen if Tcl is compiled with TCL_UTF_MAX=4,
 	 * or when a high surrogate character is detected in UTF-8 form */
-	int len2 = Tcl_UtfToUniChar(src+len, &uniChar);
+	size_t len2 = Tcl_UtfToUniChar(src+len, &uniChar);
 	if ((uniChar & 0xfc00) == 0xdc00) {
 	    *chPtr = (((high & 0x3ff) << 10) | (uniChar & 0x3ff)) + 0x10000;
 	    len += len2;
@@ -1257,9 +1256,9 @@ TkUtfToUniChar(
  *---------------------------------------------------------------------------
  */
 
-int TkUniCharToUtf(int ch, char *buf)
+size_t TkUniCharToUtf(int ch, char *buf)
 {
-    int size = Tcl_UniCharToUtf(ch, buf);
+    size_t size = Tcl_UniCharToUtf(ch, buf);
     if ((((unsigned)(ch - 0x10000) <= 0xFFFFF)) && (size < 4)) {
 	/* Hey, this is wrong, we must be running TCL_UTF_MAX==3
 	 * The best thing we can do is spit out 2 surrogates */
@@ -1272,6 +1271,27 @@ int TkUniCharToUtf(int ch, char *buf)
 
 
 #endif
+
+
+unsigned char *
+TkGetByteArrayFromObj(
+	Tcl_Obj *objPtr,
+	size_t *lengthPtr
+) {
+    int length;
+
+    unsigned char *result = Tcl_GetByteArrayFromObj(objPtr, &length);
+#ifdef TCL_WIDE_INT_IS_LONG
+    if (sizeof(TCL_HASH_TYPE) > sizeof(int)) {
+	/* 64-bit and TIP #494 situation: */
+	 *lengthPtr = *(TCL_HASH_TYPE *) objPtr->internalRep.twoPtrValue.ptr1;
+    } else
+#endif
+	/* 32-bit or without TIP #494 */
+    *lengthPtr = (size_t) (unsigned) length;
+    return result;
+}
+
 /*
  * Local Variables:
  * mode: c
diff --git a/generic/tkWindow.c b/generic/tkWindow.c
index 9afb22f..bc57165 100644
--- a/generic/tkWindow.c
+++ b/generic/tkWindow.c
@@ -3202,8 +3202,8 @@ Initialize(
      */
 
     {
-	int numBytes;
-	const char *bytes = Tcl_GetStringFromObj(nameObj, &numBytes);
+	size_t numBytes;
+	const char *bytes = TkGetStringFromObj(nameObj, &numBytes);
 
 	classObj = Tcl_NewStringObj(bytes, numBytes);
 
diff --git a/generic/ttk/ttkEntry.c b/generic/ttk/ttkEntry.c
index 16a3bbe..5c8e98b 100644
--- a/generic/ttk/ttkEntry.c
+++ b/generic/ttk/ttkEntry.c
@@ -319,7 +319,7 @@ static char *EntryDisplayString(const char *showChar, int numChars)
  */
 static void EntryUpdateTextLayout(Entry *entryPtr)
 {
-    int length;
+    size_t length;
     char *text;
     Tk_FreeTextLayout(entryPtr->entry.textLayout);
     if ((entryPtr->entry.numChars != 0) || (entryPtr->entry.placeholderObj == NULL)) {
@@ -329,7 +329,7 @@ static void EntryUpdateTextLayout(Entry *entryPtr)
 	    0/*wraplength*/, entryPtr->entry.justify, TK_IGNORE_NEWLINES,
 	    &entryPtr->entry.layoutWidth, &entryPtr->entry.layoutHeight);
     } else {
-        text = Tcl_GetStringFromObj(entryPtr->entry.placeholderObj, &length);
+        text = TkGetStringFromObj(entryPtr->entry.placeholderObj, &length);
         entryPtr->entry.textLayout = Tk_ComputeTextLayout(
 	    Tk_GetFontFromObj(entryPtr->core.tkwin, entryPtr->entry.fontObj),
 	    text, length,
@@ -1303,9 +1303,9 @@ static void EntryDisplay(void *clientData, Drawable d)
 	}
 	/* Use placeholder text width */
 	leftIndex = 0;
-        Tcl_GetStringFromObj(entryPtr->entry.placeholderObj,&rightIndex);
+	Tcl_GetStringFromObj(entryPtr->entry.placeholderObj,&rightIndex);
     } else {
-        foregroundObj = es.foregroundObj;
+	foregroundObj = es.foregroundObj;
     }
     gc = EntryGetGC(entryPtr, foregroundObj, clipRegion);
     Tk_DrawTextLayout(
@@ -1359,8 +1359,8 @@ EntryIndex(
     int *indexPtr)		/* Return value */
 {
 #   define EntryWidth(e) (Tk_Width(entryPtr->core.tkwin)) /* Not Right */
-    const char *string = Tcl_GetString(indexObj);
-    size_t length = indexObj->length;
+    size_t length;
+    const char *string = TkGetStringFromObj(indexObj, &length);
 
     if (strncmp(string, "end", length) == 0) {
 	*indexPtr = entryPtr->entry.numChars;
diff --git a/unix/tkUnixWm.c b/unix/tkUnixWm.c
index 68ab6d6..0d14e03 100644
--- a/unix/tkUnixWm.c
+++ b/unix/tkUnixWm.c
@@ -36,7 +36,7 @@ typedef struct ProtocolHandler {
 } ProtocolHandler;
 
 #define HANDLER_SIZE(cmdLength) \
-    ((unsigned) ((Tk_Offset(ProtocolHandler, command) + 1) + cmdLength))
+    (((Tk_Offset(ProtocolHandler, command) + 1) + cmdLength))
 
 /*
  * Data for [wm attributes] command:
@@ -3005,7 +3005,7 @@ WmProtocolCmd(
     register ProtocolHandler *protPtr, *prevPtr;
     Atom protocol;
     const char *cmd;
-    int cmdLength;
+    size_t cmdLength;
 
     if ((objc < 3) || (objc > 5)) {
 	Tcl_WrongNumArgs(interp, 2, objv, "window ?name? ?command?");
@@ -3071,7 +3071,7 @@ WmProtocolCmd(
 	    break;
 	}
     }
-    cmd = Tcl_GetStringFromObj(objv[4], &cmdLength);
+    cmd = TkGetStringFromObj(objv[4], &cmdLength);
     if (cmdLength > 0) {
 	protPtr = ckalloc(HANDLER_SIZE(cmdLength));
 	protPtr->protocol = protocol;
@@ -5450,8 +5450,8 @@ SetNetWmType(
 
     for (n = 0; n < objc; ++n) {
 	Tcl_DString ds, dsName;
-	int len;
-	char *name = Tcl_GetStringFromObj(objv[n], &len);
+	size_t len;
+	char *name = TkGetStringFromObj(objv[n], &len);
 
 	Tcl_UtfToUpper(name);
 	Tcl_UtfToExternalDString(NULL, name, len, &dsName);