temp

Author: lorenarosati

Cargo.lock

@@ -622,6 +622,47 @@ fn visit_expression_scalar(
         }
         Scalar::Array(array) => visit_expression_array(visitor, array, sibling_list_id),
         Scalar::Map(map_data) => visit_expression_map(visitor, map_data, sibling_list_id),
+        // v1: geo scalars are not exposed over FFI. There is no `visit_literal_geometry` /
+        // `visit_literal_geography` callback in `EngineExpressionVisitor`, and no corresponding
+        // `visit_expression_literal_geometry` / `_geography` FFI entry point exists in
+        // `kernel_visitor.rs`, so engines cannot construct these variants from C. Hitting this
+        // path means an expression containing a geo literal was built in Rust-only code and is
+        // being walked across the FFI boundary -- the CRS information carried on the Scalar is
+        // dropped here and a typed-null literal is substituted (using the Binary type tag, since
+        // geo is WKB-encoded bytes at the FFI layer) so the sibling list stays well-formed.
+        //
+        // Upgrade path: add nullable
+        // `visit_literal_geometry: Option<extern "C" fn(...)>` fields to
+        // `EngineExpressionVisitor` and sibling `extern "C" fn visit_expression_literal_geometry`
+        // kernel-side entries. Keep this arm as a fallback when the nullable field is None.
+        Scalar::Geometry(_) => {
+            tracing::error!(
+                "FFI does not yet support Scalar::Geometry; routing to null literal. \
+                 Add visit_literal_geometry callbacks to support round-tripping CRS."
+            );
+            call!(
+                visitor,
+                visit_literal_null,
+                sibling_list_id,
+                NullTypeTag::Binary as u8,
+                0,
+                0
+            )
+        }
+        Scalar::Geography(_) => {
+            tracing::error!(
+                "FFI does not yet support Scalar::Geography; routing to null literal. \
+                 Add visit_literal_geography callbacks to support round-tripping CRS."
+            );
+            call!(
+                visitor,
+                visit_literal_null,
+                sibling_list_id,
+                NullTypeTag::Binary as u8,
+                0,
+                0
+            )
+        }
     }
 }
 

ffi/src/expressions/engine_visitor.rs

@@ -60,6 +60,19 @@ z85 = "3.0.6"
 
 # optional deps
 futures = { version = "0.3", optional = true }
+# GeoArrow schema-only crate; provides geoarrow_schema::{Metadata, Crs, Edges, WkbType,
+# GeoArrowType} for type-safe Arrow extension metadata on geometry/geography columns in
+# arrow_conversion.rs. Pinned to 0.8 because geoarrow-schema 0.8 uses arrow-schema 58,
+# matching kernel's arrow_58 default dep.
+geoarrow-array = { version = "0.8", optional = true }
+geoarrow-expr-geo = { version = "0.8", optional = true }
+geoarrow-schema = { version = "0.8", optional = true }
+geo = { version = "0.32", optional = true }
+geo-traits = { version = "0.3", optional = true }
+wkb = { version = "0.9", optional = true }
+# WKT parser used by Scalar::geometry_from_wkt / geography_from_wkt. Already in Cargo.lock
+# transitively via geo-traits; promoting to an explicit dep keeps the version pinned.
+wkt = { version = "0.14", optional = true, default-features = false }
 # Used for fetching direct urls (like pre-signed urls). We disable `default-tls` to avoid
 # pulling in a second rustls crypto provider that conflicts with transitive deps (see
 # feature-tests for a regression test). Each default-engine-* feature selects its TLS backend.
@@ -112,7 +125,7 @@ need-arrow = [] # need-arrow is a marker that the feature needs arrow dep
 
 arrow-57 = ["dep:arrow_57", "dep:parquet_57", "dep:object_store_12"]
 arrow-58 = ["dep:arrow_58", "dep:parquet_58", "dep:object_store_13"]
-arrow-conversion = ["need-arrow"]
+arrow-conversion = ["need-arrow", "dep:geoarrow-array", "dep:geoarrow-schema"]
 arrow-expression = ["need-arrow"]
 
 # Schema diffing functionality (experimental)
@@ -126,6 +139,11 @@ default-engine-base = [
   "futures",
   "need-arrow",
   "tokio",
+  "dep:geo",
+  "dep:geo-traits",
+  "dep:geoarrow-expr-geo",
+  "dep:wkb",
+  "dep:wkt",
 ]
 # default-engine-native-tls enables reqwest with the native-tls backend. If you want to use
 # rustls instead, use 'default-engine-rustls' which has no native-tls dependency.