BUG: EM_LIMITTEXT Causes GPF in Japanese and Chinese Windows

RESOLUTION

LONG FAR PASCAL SubClassFunc(HWND hWnd,
                             WORD Message,
                             WORD wParam,
                             LONG lParam)
{
static BOOL bInvalidchar=FALSE; // Is this the last byte?
   if ( Message == WM_CHAR )
   {
      if (bInvalidchar==TRUE) //The trailing byte of a DBCS character
      {                       //that comes in for the last byte in edit.
         bInvalidchar=FALSE;  //Reset the flag. Next char is valid.
         return 0;            //Throw away the trailing byte.
      }
      else
      {
         // Is this the last byte?  Is the incoming WM_CHAR a DBCS
         //   leadbyte?
         if ( IsDBCSLeadByte(LOBYTE(wParam)) &&
            (( TEXTLIMIT - SendMessage(hWnd, WM_GETTEXTLENGTH, 0,0)) == 1))
         {
            bInvalidchar=TRUE;   //The character is invalid.
            return 0;               // Throw away this byte.
         }
         else return CallWindowProc(lpfnOldWndProc,
                                     hWnd,
                                     Message,
                                     wParam,
                                     lParam);
      }
   }
   else return CallWindowProc(lpfnOldWndProc,
                              hWnd,
                              Message,
                              wParam,
                              lParam);
}