Merge pull request #745 from Maxxen/v1.4-andium-dev

fix non-const vector output

Author: Maxxen

src/spatial/modules/geos/geos_module.cpp

@@ -393,6 +393,10 @@ struct ST_AsMVTGeom {
 
 			res_data[out_idx] = lstate.Serialize(result, cleaned_clipped);
 		}
+
+		if (args.AllConstant() || args.size() == 1) {
+			result.SetVectorType(VectorType::CONSTANT_VECTOR);
+		}
 	}
 
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