[OSM-dev] Underscores in PostGIS column names with Mapnik not allowed?

[Nick Whitelegg]

Hello everyone,

Am trying to add custom rendering to Freemap where the 'newforest_pathtype' or 
'newforest_landuse' tags are present. Appropriate columns in PostGIS are 
created i.e. newforest_pathtype and newforest_landuse, but they create 
problems in the Mapnik XML file.

e.g. this style rule prevents its parent style <Style name="bridleway"> being 
processed, meaning that no bridleways show up at all.

<Rule>
      <Filter>[highway] = 'bridleway' and [newforest_pathtype] = 'narrow'
      </Filter>
      <LineSymbolizer>
        <CssParameter name="stroke">#fff</CssParameter>
        <CssParameter name="stroke-width">6</CssParameter>
        <CssParameter name="stroke-linejoin">round</CssParameter>
        <CssParameter name="stroke-linecap">round</CssParameter>
        <CssParameter name="stroke-opacity">0.4</CssParameter>
      </LineSymbolizer>
      <LineSymbolizer>
        <CssParameter name="stroke">#00ff80</CssParameter>
        <CssParameter name="stroke-width">2.0</CssParameter>
        <CssParameter name="stroke-dasharray">1,4</CssParameter>
        <CssParameter name="stroke-linejoin">round</CssParameter>
        <CssParameter name="stroke-linecap">round</CssParameter>
      </LineSymbolizer>
</Rule>

Can I get round this? e.g. where in the Mapnik source can I modify it so that 
underscores are accepted?
This is with a version of Mapnik from about the beginning of March.

Thanks,
Nick