[Backport 9.4] DerivedProjectedCRS: deal with lack of explicit CS in BASEPROJCRS in WKT #4139
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…EPROJCRS Current WKT2 grammar doesn't allow an explicit CS (Coordinate System) in the BASEPROJCRS of a DERIVEDPROJCRS. This leads to ambiguities when instanciating the BASEPROJCRS. Cf OSGeo/gdal#9732 (comment) for a longer analysis When importing such a DerivedProjectedCRS, we apply the following strategy to try to reconstrut the CS of the baseProjCRS: - if the baseProjCRS has an ID[], do a datebase lookup for this object, and if found, use its CS - otherwise, do a database lookup from the name of the baseProjCRS, and if found, use its CS - otherwise, browse through the PARAMETERs of the CONVERSION of the BASEPROJCRS, and if there is at least one such PARAMETER that has a linear unit, and if all PARAMETERs with a linear unit have the same one, then use it to reconstruct a Easting/Northing CartesianCS. - otherwise, fallback to current behaviour, that is return a Easting/Northing CartesianCS with metre unit. Fixes OSGeo/gdal#9732
Current WKT grammar (as of WKT2 18-010r11) does not allow a BASEPROJCRS.CS node, but there are situations where this is ambiguous and we want to allow one. Cf OSGeo/gdal#9732 (comment)
…ns where there's ambiguity Cf OSGeo/gdal#9732 (comment)
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Backport #4124
Authored by: @rouault