BUG: fix write of kml lon/lat transpose

pyogrio/_io.pyx

@@ -2134,6 +2134,10 @@ cdef create_ogr_dataset_layer(
  if crs is not None:
  try:
  ogr_crs = create_crs(crs)
+ # force geographic CRS to use lon, lat order and ignore axis order specified by CRS, in order
+ # to correctly write KML and GeoJSON coordinates in correct order
+ OSRSetAxisMappingStrategy(ogr_crs, OAMS_TRADITIONAL_GIS_ORDER)
+
 
  except Exception as exc:
  if dataset_options != NULL:
@@ -2735,4 +2739,4 @@ cdef create_fields_from_arrow_schema(
  f"Error while creating field from Arrow for field {i} with name "
  f"'{get_string(child.name)}' and type {get_string(child.format)}"
  f"{gdal_msg}."
- )
+ )

pyogrio/_ogr.pxd

@@ -196,7 +196,10 @@ cdef extern from "ogr_srs_api.h":
  const char* OSRGetAuthorityName(OGRSpatialReferenceH srs, const char *key)
  const char* OSRGetAuthorityCode(OGRSpatialReferenceH srs, const char *key)
  OGRErr OSRImportFromEPSG(OGRSpatialReferenceH srs, int code)
-
+ ctypedef enum OSRAxisMappingStrategy:
+ OAMS_TRADITIONAL_GIS_ORDER
+
+ void OSRSetAxisMappingStrategy(OGRSpatialReferenceH hSRS, OSRAxisMappingStrategy)
  int OSRSetFromUserInput(OGRSpatialReferenceH srs, const char *pszDef)
  void OSRSetPROJSearchPaths(const char *const *paths)
  OGRSpatialReferenceH OSRNewSpatialReference(const char *wkt)

pyogrio/tests/test_geopandas_io.py

@@ -2067,3 +2067,35 @@ def test_non_utf8_encoding_shapefile_sql(tmp_path, use_arrow):
  )
  assert actual.columns[0] == mandarin
  assert actual[mandarin].values[0] == mandarin
+
+
+def test_write_kml_file_coordinate_order(tmp_path, use_arrow):
+ # confirm KML coordinates are written in lon, lat order even if CRS axis specifies otherwise
+ points = [Point(10, 20), Point(30, 40), Point(50, 60)]
+ gdf = gp.GeoDataFrame(geometry=points, crs="EPSG:4326")
+ output_path = tmp_path / "test.kml"
+ write_dataframe(
+ gdf, output_path, layer="tmp_layer", driver="KML", use_arrow=use_arrow
+ )
+
+ gdf_in = read_dataframe(output_path, use_arrow=use_arrow)
+
+ assert np.array_equal(gdf_in.geometry.values, points)
+
+
+def test_write_geojson_rfc7946_coordinates(tmp_path, use_arrow=use_arrow):
+ points = [Point(10, 20), Point(30, 40), Point(50, 60)]
+ gdf = gp.GeoDataFrame(geometry=points, crs="EPSG:4326")
+ output_path = tmp_path / "test.geojson"
+ write_dataframe(
+ gdf,
+ output_path,
+ layer="tmp_layer",
+ driver="GeoJSON",
+ RFC7946=True,
+ use_arrow=use_arrow,
+ )
+
+ gdf_in = read_dataframe(output_path, use_arrow=use_arrow)
+
+ assert np.array_equal(gdf_in.geometry.values, points)