Terria Filter By Location does not work when requesting a point with no data for the specified date

[meh9]

When using Terria at e.g. https://maps.dea.ga.gov.au/#share=s-ptlkkuwWh7FV19QZQe9xvccOmkt and doing a Filter By Location request, this will only work if you click on an area that has coverage for the particular date you are one, and will fail when done for an area with no cover.

E.g. a request here will succeed:

But a request here will fail:

An example of a Filter By Location request URL that succeeds:

https://ows.dea.ga.gov.au/?time=2021-03-05&srs=EPSG%3A3857&transparent=true&format=image%2Fpng&exceptions=application%2Fvnd.ogc.se_xml&styles=&tiled=true&feature_count=101&service=WMS&version=1.1.1&request=GetFeatureInfo&layers=s2_ard_granule_nbar_t&bbox=12523442.714243278%2C-5009377.085697312%2C15028131.257091936%2C-2504688.542848654&width=256&height=256&query_layers=s2_ard_granule_nbar_t&x=166&y=66&info_format=application%2Fjson

An example of a request URL that fails:

https://ows.dea.ga.gov.au/?time=2021-03-05&srs=EPSG%3A3857&transparent=true&format=image%2Fpng&exceptions=application%2Fvnd.ogc.se_xml&styles=&tiled=true&feature_count=101&service=WMS&version=1.1.1&request=GetFeatureInfo&layers=s2_ard_granule_nbar_t&bbox=12523442.714243278%2C-5009377.085697312%2C15028131.257091936%2C-2504688.542848654&width=256&height=256&query_layers=s2_ard_granule_nbar_t&x=99&y=41&info_format=application%2Fjson

And the error message:

<?xml version='1.0' encoding="UTF-8"?>
<ServiceExceptionReport version="1.3.0"
xmlns="http://www.opengis.net/ogc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.opengis.net/ogc http://schemas.opengis.net/wms/1.3.0/exceptions_1_3_0.xsd">
  
    <ServiceException>
        Unexpected server error: local variable &#39;pt&#39; referenced before assignment   
    </ServiceException>
    
    <ServiceException>   
        <![CDATA[ <FrameSummary file /env/lib/python3.6/site-packages/datacube_ows/ogc.py, line 125 in ogc_svc_impl> ]]>   
        <![CDATA[ <FrameSummary file /env/lib/python3.6/site-packages/datacube_ows/utils.py, line 14 in log_wrapper> ]]>   
        <![CDATA[ <FrameSummary file /env/lib/python3.6/site-packages/datacube_ows/wms.py, line 28 in handle_wms> ]]>   
        <![CDATA[ <FrameSummary file /env/lib/python3.6/site-packages/datacube_ows/utils.py, line 14 in log_wrapper> ]]>   
        <![CDATA[ <FrameSummary file /env/lib/python3.6/site-packages/datacube_ows/data.py, line 807 in feature_info> ]]>   
    </ServiceException>
</ServiceExceptionReport>

This was noticed by the stakeholders of the National Drought Map.

[SpacemanPaul]

Appears to be a datacube_ows bug. This should fix it:

opendatacube/datacube-ows#527