Consider a WMS capability document as below:
<!DOCTYPE WMT_MS_Capabilities SYSTEM "http://schemas.opengis.net/wms/1.1.1/WMS_MS_Capabilities.dtd">
<WMT_MS_Capabilities version="1.1.1" updateSequence="473">
<Service>
<Name>WMS</Name>
<Title>WMS</Title>
<Abstract>caps document for a WMS 1.1.1 server without formats and a styleless layer</Abstract>
<KeywordList>
<Keyword>GEOSERVER</Keyword>
</KeywordList>
<OnlineResource xmlns:xlink="http://www.w3.org/1999/xlink" xlink:type="simple" xlink:href="http://mock.test.geoserver.org"/>
</Service>
<Capability>
<Request>
<GetCapabilities>
<Format>application/vnd.ogc.wms_xml</Format>
<DCPType>
<HTTP>
<Get>
<OnlineResource xmlns:xlink="http://www.w3.org/1999/xlink" xlink:type="simple" xlink:href="http://mock.test.geoserver.org/wms11?SERVICE=WMS&"/>
</Get>
<Post>
<OnlineResource xmlns:xlink="http://www.w3.org/1999/xlink" xlink:type="simple" xlink:href="http://mock.test.geoserver.org/wms11?SERVICE=WMS&"/>
</Post>
</HTTP>
</DCPType>
</GetCapabilities>
<GetMap>
<DCPType>
<HTTP>
<Get>
<OnlineResource xmlns:xlink="http://www.w3.org/1999/xlink" xlink:type="simple" xlink:href="http://mock.test.geoserver.org/wms11?SERVICE=WMS&"/>
</Get>
</HTTP>
</DCPType>
</GetMap>
<GetFeatureInfo>
<Format>text/plain</Format>
<Format>application/vnd.ogc.gml</Format>
<Format>application/vnd.ogc.gml/3.1.1</Format>
<Format>text/html</Format>
<Format>application/json</Format>
<DCPType>
<HTTP>
<Get>
<OnlineResource xmlns:xlink="http://www.w3.org/1999/xlink" xlink:type="simple" xlink:href="http://mock.test.geoserver.org/wms11?SERVICE=WMS&"/>
</Get>
<Post>
<OnlineResource xmlns:xlink="http://www.w3.org/1999/xlink" xlink:type="simple" xlink:href="http://mock.test.geoserver.org/wms11?SERVICE=WMS&"/>
</Post>
</HTTP>
</DCPType>
</GetFeatureInfo>
</Request>
<Exception>
<Format>application/vnd.ogc.se_xml</Format>
<Format>application/vnd.ogc.se_inimage</Format>
</Exception>
<UserDefinedSymbolization SupportSLD="1" UserLayer="1" UserStyle="1" RemoteWFS="1"/>
<Layer>
<Title>Root</Title>
<SRS>EPSG:4326</SRS>
<LatLonBoundingBox minx="-180.0" miny="-90.0" maxx="180" maxy="90"/>
<Layer queryable="1" opaque="0">
<Name>topp:states_styless</Name>
<Title>states_styless</Title>
<Abstract>I am a styless layer in format less capability document</Abstract>
<KeywordList>
<Keyword>states</Keyword>
</KeywordList>
<SRS>EPSG:4326</SRS>
<LatLonBoundingBox minx="36.0460729490001" miny="32.614108317" maxx="36.153265193" maxy="32.686323626"/>
<BoundingBox SRS="EPSG:4326" minx="36.0460729490001" miny="32.614108317" maxx="36.153265193" maxy="32.686323626"/>
</Layer>
</Layer>
</Capability>
</WMT_MS_Capabilities>
For such cases the WMS Cascaded settings under Publishing tab on Layer Page should show default format selected as **image/png**. Currently it defaults to no selection because the list is empty. In case of empty format list the default should be added to keep GUI consistent with bean state.
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