Index: generic/tcl.decls
==================================================================
--- generic/tcl.decls
+++ generic/tcl.decls
@@ -2351,11 +2351,11 @@
 declare 636 {
     void Tcl_FreeIntRep(Tcl_Obj *objPtr)
 }
 declare 637 {
     char *Tcl_InitStringRep(Tcl_Obj *objPtr, const char *bytes,
-	    unsigned int numBytes)
+	    size_t numBytes)
 }
 declare 638 {
     Tcl_ObjIntRep *Tcl_FetchIntRep(Tcl_Obj *objPtr, const Tcl_ObjType *typePtr)
 }
 declare 639 {

Index: generic/tclDecls.h
==================================================================
--- generic/tclDecls.h
+++ generic/tclDecls.h
@@ -1879,11 +1879,11 @@
 				size_t datalen, int copy);
 /* 636 */
 EXTERN void		Tcl_FreeIntRep(Tcl_Obj *objPtr);
 /* 637 */
 EXTERN char *		Tcl_InitStringRep(Tcl_Obj *objPtr, const char *bytes,
-				unsigned int numBytes);
+				size_t numBytes);
 /* 638 */
 EXTERN Tcl_ObjIntRep *	Tcl_FetchIntRep(Tcl_Obj *objPtr,
 				const Tcl_ObjType *typePtr);
 /* 639 */
 EXTERN void		Tcl_StoreIntRep(Tcl_Obj *objPtr,
@@ -2571,11 +2571,11 @@
     int (*tclZipfs_Mount) (Tcl_Interp *interp, const char *mountPoint, const char *zipname, const char *passwd); /* 632 */
     int (*tclZipfs_Unmount) (Tcl_Interp *interp, const char *mountPoint); /* 633 */
     Tcl_Obj * (*tclZipfs_TclLibrary) (void); /* 634 */
     int (*tclZipfs_MountBuffer) (Tcl_Interp *interp, const char *mountPoint, unsigned char *data, size_t datalen, int copy); /* 635 */
     void (*tcl_FreeIntRep) (Tcl_Obj *objPtr); /* 636 */
-    char * (*tcl_InitStringRep) (Tcl_Obj *objPtr, const char *bytes, unsigned int numBytes); /* 637 */
+    char * (*tcl_InitStringRep) (Tcl_Obj *objPtr, const char *bytes, size_t numBytes); /* 637 */
     Tcl_ObjIntRep * (*tcl_FetchIntRep) (Tcl_Obj *objPtr, const Tcl_ObjType *typePtr); /* 638 */
     void (*tcl_StoreIntRep) (Tcl_Obj *objPtr, const Tcl_ObjType *typePtr, const Tcl_ObjIntRep *irPtr); /* 639 */
     int (*tcl_HasStringRep) (Tcl_Obj *objPtr); /* 640 */
     void (*tcl_IncrRefCount) (Tcl_Obj *objPtr); /* 641 */
     void (*tcl_DecrRefCount) (Tcl_Obj *objPtr); /* 642 */

Index: generic/tclObj.c
==================================================================
--- generic/tclObj.c
+++ generic/tclObj.c
@@ -1718,28 +1718,28 @@
  *
  *	This function is called in several configurations to provide all
  *	the tools needed to set an object's string representation. The
  *	function is determined by the arguments.
  *
- *	(objPtr->bytes != NULL && bytes != NULL) || (numBytes < 0)
+ *	objPtr->bytes != NULL && bytes != NULL
  *	    Invalid call -- panic!
  *
- *	objPtr->bytes == NULL && bytes == NULL && numBytes >= 0
+ *	objPtr->bytes == NULL && bytes == NULL
  *	    Allocation only - allocate space for (numBytes+1) chars.
  *	    store in objPtr->bytes and return. Also sets
  *	    objPtr->length to 0 and objPtr->bytes[0] to NUL.
  *
- *	objPtr->bytes == NULL && bytes != NULL && numBytes >= 0
+ *	objPtr->bytes == NULL && bytes != NULL
  *	    Allocate and copy. bytes is assumed to point to chars to
  *	    copy into the string rep. objPtr->length = numBytes. Allocate
  *	    array of (numBytes + 1) chars. store in objPtr->bytes. Copy
  *	    numBytes chars from bytes to objPtr->bytes; Set
  *	    objPtr->bytes[numBytes] to NUL and return objPtr->bytes.
  *	    Caller must guarantee there are numBytes chars at bytes to
  *	    be copied.
  *
- *	objPtr->bytes != NULL && bytes == NULL && numBytes >= 0
+ *	objPtr->bytes != NULL && bytes == NULL
  *	    Truncate.  Set objPtr->length to numBytes and
  *	    objPr->bytes[numBytes] to NUL.  Caller has to guarantee
  *	    that a prior allocating call allocated enough bytes for
  *	    this to be valid. Return objPtr->bytes.
  *
@@ -1757,16 +1757,16 @@
 
 char *
 Tcl_InitStringRep(
     Tcl_Obj *objPtr,	/* Object whose string rep is to be set */
     const char *bytes,
-    unsigned int numBytes)
+    size_t numBytes)
 {
     assert(objPtr->bytes == NULL || bytes == NULL);
 
     if (numBytes > INT_MAX) {
-	Tcl_Panic("max size for a Tcl value (%d bytes) exceeded", INT_MAX);
+	return NULL;
     }
 
     /* Allocate */
     if (objPtr->bytes == NULL) {
 	/* Allocate only as empty - extend later if bytes copied */