Make sure proj_get_source_crs() and proj_get_target_crs() work on 'pseudo' PJ object returned by proj_create_crs_to_crs() when there are several alternatives

2 files changed, 20 insertions, 0 deletions

diff --git a/src/iso19111/c_api.cpp b/src/iso19111/c_api.cpp
index 240d11b3..79732bab 100644
--- a/src/iso19111/c_api.cpp
+++ b/src/iso19111/c_api.cpp
@@ -1736,6 +1736,10 @@ PJ *proj_get_source_crs(PJ_CONTEXT *ctx, const PJ *obj) {
         }
         return nullptr;
     }
+    if (!obj->alternativeCoordinateOperations.empty()) {
+        return proj_get_source_crs(ctx,
+                                   obj->alternativeCoordinateOperations[0].pj);
+    }
     proj_log_error(ctx, __FUNCTION__,
                    "Object is not a BoundCRS or a CoordinateOperation");
     return nullptr;
@@ -1771,6 +1775,10 @@ PJ *proj_get_target_crs(PJ_CONTEXT *ctx, const PJ *obj) {
         }
         return nullptr;
     }
+    if (!obj->alternativeCoordinateOperations.empty()) {
+        return proj_get_target_crs(ctx,
+                                   obj->alternativeCoordinateOperations[0].pj);
+    }
     proj_log_error(ctx, __FUNCTION__,
                    "Object is not a BoundCRS or a CoordinateOperation");
     return nullptr;
diff --git a/test/unit/gie_self_tests.cpp b/test/unit/gie_self_tests.cpp
index 91a3069c..5936791e 100644
--- a/test/unit/gie_self_tests.cpp
+++ b/test/unit/gie_self_tests.cpp
@@ -680,6 +680,18 @@ TEST(gie, proj_create_crs_to_crs_PULKOVO42_ETRS89) {
     EXPECT_EQ(P->fwd3d, nullptr);
     EXPECT_EQ(P->fwd4d, nullptr);
 
+    // get source CRS even if the P object is in a dummy state
+    auto src_crs = proj_get_source_crs(PJ_DEFAULT_CTX, P);
+    EXPECT_TRUE(src_crs != nullptr);
+    EXPECT_EQ(proj_get_name(src_crs), std::string("Pulkovo 1942(58)"));
+    proj_destroy(src_crs);
+
+    // get target CRS even if the P object is in a dummy state
+    auto target_crs = proj_get_target_crs(PJ_DEFAULT_CTX, P);
+    EXPECT_TRUE(target_crs != nullptr);
+    EXPECT_EQ(proj_get_name(target_crs), std::string("ETRS89"));
+    proj_destroy(target_crs);
+
     // Romania
     c.xyz.x = 45; // Lat
     c.xyz.y = 25; // Long