if ( mPosition == mFragment.mStart ) if ( mOwningString->GetReadableFragment(mFragment, kPrevFragment) )
while ( mPosition == mFragment.mStart && mOwningString->GetReadableFragment(mFragment, kPrevFragment) )
nsReadingIterator<CharT>::normalize_backward()  {    if ( mPosition == mFragment.mStart )      if ( mOwningString->GetReadableFragment(mFragment, kPrevFragment) )        mPosition = mFragment.mEnd;  }