ReadNextPoint fails when filtering and EOF is reached

[tcommandeur]

When using libLAS for reading LAS and LAZ files while filtering using the built in filters I ran into some issues.

If a filter is applied and a LAS is used the code (ReaderImpl::ReadNextPoint()) will return an out_of_range exception if the stream is EOF, this exception is caught by Reader::ReadNextPoint()

    try
    {
        m_pimpl->ReadNextPoint();
        return true;
    }
    catch (std::out_of_range const&)
    {
    }

If a filter is applied and a LAZ is used the code (ZipReaderImpl::ReadNextPoint()) will use ReadIdiom() with the following code:

    bool ok = m_unzipper->read(m_zipPoint->m_lz_point);

    if (!ok)
    {
        std::ostringstream oss;
        const char* errMsg = m_unzipper->get_error();
        oss << "Error reading compressed point data: " ;
        if (errMsg)
            oss << "'" << m_unzipper->get_error() <<"'";
        else
            oss << "no message from LASzip library";
        throw liblas_error(oss.str());
    }

This function throws a liblas_error and this exception is NOT caught by Reader::ReadNextPoint().

Neither implementation handle the out_of_bounds in a clean fashion since they read the next point before checking if the stream is EOF.

The code below is used for reading in zipreader, I was wondering why it has the if(!FilterPoint(*m_point)) in the first place?

    if (!FilterPoint(*m_point))
    {
        ReadIdiom();

        while (!FilterPoint(*m_point))
        {
            ReadIdiom();
            if (m_current == m_size) 
            {
                bLastPoint = true;
                break;
            }
        }
    }