When reading from database, possibly return Geographic/GeodeticCRS with a DatumEnsemble, typically for WGS 84 and ETRS89 ('breaking change')

3 files changed, 124 insertions, 21 deletions

diff --git a/test/cli/testprojinfo_out.dist b/test/cli/testprojinfo_out.dist
index 7da5add7..2d4990ee 100644
--- a/test/cli/testprojinfo_out.dist
+++ b/test/cli/testprojinfo_out.dist
@@ -4,9 +4,16 @@ PROJ.4 string:
 
 WKT2:2019 string:
 GEOGCRS["WGS 84",
-    DATUM["World Geodetic System 1984",
+    ENSEMBLE["World Geodetic System 1984 ensemble",
+        MEMBER["World Geodetic System 1984 (Transit)"],
+        MEMBER["World Geodetic System 1984 (G730)"],
+        MEMBER["World Geodetic System 1984 (G873)"],
+        MEMBER["World Geodetic System 1984 (G1150)"],
+        MEMBER["World Geodetic System 1984 (G1674)"],
+        MEMBER["World Geodetic System 1984 (G1762)"],
         ELLIPSOID["WGS 84",6378137,298.257223563,
-            LENGTHUNIT["metre",1]]],
+            LENGTHUNIT["metre",1]],
+        ENSEMBLEACCURACY[2.0]],
     PRIMEM["Greenwich",0,
         ANGLEUNIT["degree",0.0174532925199433]],
     CS[ellipsoidal,2],
@@ -59,9 +66,16 @@ GEODCRS["WGS 84",
 Testing projinfo -o WKT2_2019 EPSG:4326
 WKT2:2019 string:
 GEOGCRS["WGS 84",
-    DATUM["World Geodetic System 1984",
+    ENSEMBLE["World Geodetic System 1984 ensemble",
+        MEMBER["World Geodetic System 1984 (Transit)"],
+        MEMBER["World Geodetic System 1984 (G730)"],
+        MEMBER["World Geodetic System 1984 (G873)"],
+        MEMBER["World Geodetic System 1984 (G1150)"],
+        MEMBER["World Geodetic System 1984 (G1674)"],
+        MEMBER["World Geodetic System 1984 (G1762)"],
         ELLIPSOID["WGS 84",6378137,298.257223563,
-            LENGTHUNIT["metre",1]]],
+            LENGTHUNIT["metre",1]],
+        ENSEMBLEACCURACY[2.0]],
     PRIMEM["Greenwich",0,
         ANGLEUNIT["degree",0.0174532925199433]],
     CS[ellipsoidal,2],
@@ -102,9 +116,16 @@ GEODCRS["WGS 84",
 
 WKT2:2019 string:
 GEOGCRS["WGS 84",
-    DATUM["World Geodetic System 1984",
+    ENSEMBLE["World Geodetic System 1984 ensemble",
+        MEMBER["World Geodetic System 1984 (Transit)"],
+        MEMBER["World Geodetic System 1984 (G730)"],
+        MEMBER["World Geodetic System 1984 (G873)"],
+        MEMBER["World Geodetic System 1984 (G1150)"],
+        MEMBER["World Geodetic System 1984 (G1674)"],
+        MEMBER["World Geodetic System 1984 (G1762)"],
         ELLIPSOID["WGS 84",6378137,298.257223563,
-            LENGTHUNIT["metre",1]]],
+            LENGTHUNIT["metre",1]],
+        ENSEMBLEACCURACY[2.0]],
     PRIMEM["Greenwich",0,
         ANGLEUNIT["degree",0.0174532925199433]],
     CS[ellipsoidal,2],
@@ -142,13 +163,61 @@ PROJJSON:
   "$schema": "https://proj.org/schemas/v0.2/projjson.schema.json",
   "type": "GeographicCRS",
   "name": "WGS 84",
-  "datum": {
-    "type": "GeodeticReferenceFrame",
-    "name": "World Geodetic System 1984",
+  "datum_ensemble": {
+    "name": "World Geodetic System 1984 ensemble",
+    "members": [
+      {
+        "name": "World Geodetic System 1984 (Transit)",
+        "id": {
+          "authority": "EPSG",
+          "code": 1166
+        }
+      },
+      {
+        "name": "World Geodetic System 1984 (G730)",
+        "id": {
+          "authority": "EPSG",
+          "code": 1152
+        }
+      },
+      {
+        "name": "World Geodetic System 1984 (G873)",
+        "id": {
+          "authority": "EPSG",
+          "code": 1153
+        }
+      },
+      {
+        "name": "World Geodetic System 1984 (G1150)",
+        "id": {
+          "authority": "EPSG",
+          "code": 1154
+        }
+      },
+      {
+        "name": "World Geodetic System 1984 (G1674)",
+        "id": {
+          "authority": "EPSG",
+          "code": 1155
+        }
+      },
+      {
+        "name": "World Geodetic System 1984 (G1762)",
+        "id": {
+          "authority": "EPSG",
+          "code": 1156
+        }
+      }
+    ],
     "ellipsoid": {
       "name": "WGS 84",
       "semi_major_axis": 6378137,
       "inverse_flattening": 298.257223563
+    },
+    "accuracy": "2.0",
+    "id": {
+      "authority": "EPSG",
+      "code": 6326
     }
   },
   "coordinate_system": {
@@ -1023,9 +1092,16 @@ PROJ.4 string:
 WKT2:2019 string:
 PROJCRS["WGS 84 / UTM zone 31N",
     BASEGEOGCRS["WGS 84",
-        DATUM["World Geodetic System 1984",
+        ENSEMBLE["World Geodetic System 1984 ensemble",
+            MEMBER["World Geodetic System 1984 (Transit)"],
+            MEMBER["World Geodetic System 1984 (G730)"],
+            MEMBER["World Geodetic System 1984 (G873)"],
+            MEMBER["World Geodetic System 1984 (G1150)"],
+            MEMBER["World Geodetic System 1984 (G1674)"],
+            MEMBER["World Geodetic System 1984 (G1762)"],
             ELLIPSOID["WGS 84",6378137,298.257223563,
-                LENGTHUNIT["metre",1]]],
+                LENGTHUNIT["metre",1]],
+            ENSEMBLEACCURACY[2.0]],
         PRIMEM["Greenwich",0,
             ANGLEUNIT["degree",0.0174532925199433]],
         ID["EPSG",4979]],
@@ -1198,9 +1274,23 @@ Testing -k operation EPSG:8457 -o PROJ -q
 
 Testing D_WGS_1984
 WKT2:2019 string:
-DATUM["World Geodetic System 1984",
+ENSEMBLE["World Geodetic System 1984 ensemble",
+    MEMBER["World Geodetic System 1984 (Transit)",
+        ID["EPSG",1166]],
+    MEMBER["World Geodetic System 1984 (G730)",
+        ID["EPSG",1152]],
+    MEMBER["World Geodetic System 1984 (G873)",
+        ID["EPSG",1153]],
+    MEMBER["World Geodetic System 1984 (G1150)",
+        ID["EPSG",1154]],
+    MEMBER["World Geodetic System 1984 (G1674)",
+        ID["EPSG",1155]],
+    MEMBER["World Geodetic System 1984 (G1762)",
+        ID["EPSG",1156]],
     ELLIPSOID["WGS 84",6378137,298.257223563,
-        LENGTHUNIT["metre",1]],
+        LENGTHUNIT["metre",1],
+        ID["EPSG",7030]],
+    ENSEMBLEACCURACY[2.0],
     ID["EPSG",6326]]
 
 Testing -k datum D_WGS_1984
diff --git a/test/unit/test_c_api.cpp b/test/unit/test_c_api.cpp
index 5da6b369..a72aa72e 100644
--- a/test/unit/test_c_api.cpp
+++ b/test/unit/test_c_api.cpp
@@ -4841,9 +4841,16 @@ TEST_F(CApi, proj_create_derived_geographic_crs) {
     const char *expected_wkt =
         "GEOGCRS[\"my rotated CRS\",\n"
         "    BASEGEOGCRS[\"WGS 84\",\n"
-        "        DATUM[\"World Geodetic System 1984\",\n"
+        "        ENSEMBLE[\"World Geodetic System 1984 ensemble\",\n"
+        "            MEMBER[\"World Geodetic System 1984 (Transit)\"],\n"
+        "            MEMBER[\"World Geodetic System 1984 (G730)\"],\n"
+        "            MEMBER[\"World Geodetic System 1984 (G873)\"],\n"
+        "            MEMBER[\"World Geodetic System 1984 (G1150)\"],\n"
+        "            MEMBER[\"World Geodetic System 1984 (G1674)\"],\n"
+        "            MEMBER[\"World Geodetic System 1984 (G1762)\"],\n"
         "            ELLIPSOID[\"WGS 84\",6378137,298.257223563,\n"
-        "                LENGTHUNIT[\"metre\",1]]],\n"
+        "                LENGTHUNIT[\"metre\",1]],\n"
+        "            ENSEMBLEACCURACY[2.0]],\n"
         "        PRIMEM[\"Greenwich\",0,\n"
         "            ANGLEUNIT[\"degree\",0.0174532925199433]]],\n"
         "    DERIVINGCONVERSION[\"Pole rotation (GRIB convention)\",\n"
diff --git a/test/unit/test_factory.cpp b/test/unit/test_factory.cpp
index 1005d49b..c869fa50 100644
--- a/test/unit/test_factory.cpp
+++ b/test/unit/test_factory.cpp
@@ -531,8 +531,10 @@ TEST(factory, AuthorityFactory_createGeodeticCRS_geographic2D) {
     EXPECT_EQ(gcrs->identifiers()[0]->code(), "4326");
     EXPECT_EQ(*(gcrs->identifiers()[0]->codeSpace()), "EPSG");
     EXPECT_EQ(*(gcrs->name()->description()), "WGS 84");
-    EXPECT_TRUE(
-        gcrs->datum()->isEquivalentTo(factory->createDatum("6326").get()));
+    ASSERT_TRUE(gcrs->datum() == nullptr);
+    ASSERT_TRUE(gcrs->datumEnsemble() != nullptr);
+    EXPECT_TRUE(gcrs->datumEnsemble()->isEquivalentTo(
+        factory->createDatumEnsemble("6326").get()));
     EXPECT_TRUE(gcrs->coordinateSystem()->isEquivalentTo(
         factory->createCoordinateSystem("6422").get()));
     auto domain = crs->domains()[0];
@@ -566,8 +568,10 @@ TEST(factory, AuthorityFactory_createGeodeticCRS_geographic3D) {
     EXPECT_EQ(gcrs->identifiers()[0]->code(), "4979");
     EXPECT_EQ(*(gcrs->identifiers()[0]->codeSpace()), "EPSG");
     EXPECT_EQ(*(gcrs->name()->description()), "WGS 84");
-    EXPECT_TRUE(
-        gcrs->datum()->isEquivalentTo(factory->createDatum("6326").get()));
+    ASSERT_TRUE(gcrs->datum() == nullptr);
+    ASSERT_TRUE(gcrs->datumEnsemble() != nullptr);
+    EXPECT_TRUE(gcrs->datumEnsemble()->isEquivalentTo(
+        factory->createDatumEnsemble("6326").get()));
     EXPECT_TRUE(gcrs->coordinateSystem()->isEquivalentTo(
         factory->createCoordinateSystem("6423").get()));
 }
@@ -582,8 +586,10 @@ TEST(factory, AuthorityFactory_createGeodeticCRS_geocentric) {
     EXPECT_EQ(crs->identifiers()[0]->code(), "4978");
     EXPECT_EQ(*(crs->identifiers()[0]->codeSpace()), "EPSG");
     EXPECT_EQ(*(crs->name()->description()), "WGS 84");
-    EXPECT_TRUE(
-        crs->datum()->isEquivalentTo(factory->createDatum("6326").get()));
+    ASSERT_TRUE(crs->datum() == nullptr);
+    ASSERT_TRUE(crs->datumEnsemble() != nullptr);
+    EXPECT_TRUE(crs->datumEnsemble()->isEquivalentTo(
+        factory->createDatumEnsemble("6326").get()));
     EXPECT_TRUE(crs->coordinateSystem()->isEquivalentTo(
         factory->createCoordinateSystem("6500").get()));
 }