code: private int getUpdatedPadding()
  	{
  		int curSize = getSize();
  		int pad = 0;
  
  		if ((origPadding == padding) && (curSize > origSize) && (padding >= (curSize - origSize)))
  		{
  			pad = padding - (curSize - origSize);
  		}
  		else if (curSize < origSize)
  		{
  			pad = (origSize - curSize) + padding;
  		}
  
  		return pad;
  	}
docs: Determines the new amount of padding to use.  If the user has not
  changed the amount of padding then existing padding will be overwritten
  instead of increasing the size of the file.  That is only if there is
  a sufficient amount of padding for the updated tag.
  
  @return the new amount of padding