Make GeographicCRS/GeodeticCRS::isEquivalentTo() work properly when comparing to a DerivedGeographicCRS/DerivedGeodeticCRS

4 files changed, 55 insertions, 9 deletions

diff --git a/include/proj/crs.hpp b/include/proj/crs.hpp
index ec755728..b921f4bb 100644
--- a/include/proj/crs.hpp
+++ b/include/proj/crs.hpp
@@ -340,6 +340,11 @@ class PROJ_GCC_DLL GeodeticCRS : virtual public SingleCRS,
     PROJ_INTERNAL std::list<std::pair<CRSNNPtr, int>>
     _identify(const io::AuthorityFactoryPtr &authorityFactory) const override;
 
+    PROJ_INTERNAL bool
+    _isEquivalentToNoTypeCheck(const util::IComparable *other,
+                               util::IComparable::Criterion criterion,
+                               const io::DatabaseContextPtr &dbContext) const;
+
     INLINED_MAKE_SHARED
 
   private:
diff --git a/include/proj/util.hpp b/include/proj/util.hpp
index 3d85e579..2ada4f79 100644
--- a/include/proj/util.hpp
+++ b/include/proj/util.hpp
@@ -213,6 +213,14 @@ template <typename T> using nn_shared_ptr = nn<std::shared_ptr<T>>;
 // To avoid formatting differences between clang-format 3.8 and 7
 #define PROJ_NOEXCEPT noexcept
 
+//! @cond Doxygen_Suppress
+// isOfExactType<MyType>(*p) checks that the type of *p is exactly MyType
+template <typename TemplateT, typename ObjectT>
+inline bool isOfExactType(const ObjectT &o) {
+    return typeid(TemplateT).hash_code() == typeid(o).hash_code();
+}
+//! @endcond
+
 /** \brief Loose transposition of [std::optional]
  * (https://en.cppreference.com/w/cpp/utility/optional) available from C++17. */
 template <class T> class optional {
diff --git a/src/iso19111/crs.cpp b/src/iso19111/crs.cpp
index 84b98984..de882105 100644
--- a/src/iso19111/crs.cpp
+++ b/src/iso19111/crs.cpp
@@ -1926,11 +1926,19 @@ getStandardCriterion(util::IComparable::Criterion criterion) {
 bool GeodeticCRS::_isEquivalentTo(
     const util::IComparable *other, util::IComparable::Criterion criterion,
     const io::DatabaseContextPtr &dbContext) const {
+    if (other == nullptr || !util::isOfExactType<GeodeticCRS>(*other)) {
+        return false;
+    }
+    return _isEquivalentToNoTypeCheck(other, criterion, dbContext);
+}
+
+bool GeodeticCRS::_isEquivalentToNoTypeCheck(
+    const util::IComparable *other, util::IComparable::Criterion criterion,
+    const io::DatabaseContextPtr &dbContext) const {
     const auto standardCriterion = getStandardCriterion(criterion);
-    auto otherGeodCRS = dynamic_cast<const GeodeticCRS *>(other);
+
     // TODO test velocityModel
-    return otherGeodCRS != nullptr &&
-           SingleCRS::baseIsEquivalentTo(other, standardCriterion, dbContext);
+    return SingleCRS::baseIsEquivalentTo(other, standardCriterion, dbContext);
 }
 //! @endcond
 
@@ -2486,12 +2494,13 @@ bool GeographicCRS::is2DPartOf3D(util::nn<const GeographicCRS *> other,
 bool GeographicCRS::_isEquivalentTo(
     const util::IComparable *other, util::IComparable::Criterion criterion,
     const io::DatabaseContextPtr &dbContext) const {
-    auto otherGeogCRS = dynamic_cast<const GeographicCRS *>(other);
-    if (otherGeogCRS == nullptr) {
+    if (other == nullptr || !util::isOfExactType<GeographicCRS>(*other)) {
         return false;
     }
+
     const auto standardCriterion = getStandardCriterion(criterion);
-    if (GeodeticCRS::_isEquivalentTo(other, standardCriterion, dbContext)) {
+    if (GeodeticCRS::_isEquivalentToNoTypeCheck(other, standardCriterion,
+                                                dbContext)) {
         return true;
     }
     if (criterion !=
@@ -2510,7 +2519,8 @@ bool GeographicCRS::_isEquivalentTo(
                            cs::EllipsoidalCS::AxisOrder::LONG_EAST_LAT_NORTH
                        ? cs::EllipsoidalCS::createLatitudeLongitude(unit)
                        : cs::EllipsoidalCS::createLongitudeLatitude(unit))
-            ->GeodeticCRS::_isEquivalentTo(other, standardCriterion, dbContext);
+            ->GeodeticCRS::_isEquivalentToNoTypeCheck(other, standardCriterion,
+                                                      dbContext);
     }
     return false;
 }
@@ -3889,8 +3899,7 @@ ProjectedCRS::create(const util::PropertyMap &properties,
 bool ProjectedCRS::_isEquivalentTo(
     const util::IComparable *other, util::IComparable::Criterion criterion,
     const io::DatabaseContextPtr &dbContext) const {
-    auto otherProjCRS = dynamic_cast<const ProjectedCRS *>(other);
-    return otherProjCRS != nullptr &&
+    return other != nullptr && util::isOfExactType<ProjectedCRS>(*other) &&
            DerivedCRS::_isEquivalentTo(other, criterion, dbContext);
 }
 
diff --git a/test/unit/test_crs.cpp b/test/unit/test_crs.cpp
index 38afdce3..aea72da2 100644
--- a/test/unit/test_crs.cpp
+++ b/test/unit/test_crs.cpp
@@ -4750,6 +4750,18 @@ static DerivedGeographicCRSNNPtr createDerivedGeographicCRS() {
 
 // ---------------------------------------------------------------------------
 
+TEST(crs, derivedGeographicCRS_basic) {
+
+    auto derivedCRS = createDerivedGeographicCRS();
+    EXPECT_TRUE(derivedCRS->isEquivalentTo(derivedCRS.get()));
+    EXPECT_FALSE(derivedCRS->isEquivalentTo(
+        derivedCRS->baseCRS().get(), IComparable::Criterion::EQUIVALENT));
+    EXPECT_FALSE(derivedCRS->baseCRS()->isEquivalentTo(
+        derivedCRS.get(), IComparable::Criterion::EQUIVALENT));
+}
+
+// ---------------------------------------------------------------------------
+
 TEST(crs, derivedGeographicCRS_WKT2) {
 
     auto expected = "GEODCRS[\"WMO Atlantic Pole\",\n"
@@ -4950,6 +4962,18 @@ static DerivedGeodeticCRSNNPtr createDerivedGeodeticCRS() {
 
 // ---------------------------------------------------------------------------
 
+TEST(crs, derivedGeodeticCRS_basic) {
+
+    auto derivedCRS = createDerivedGeodeticCRS();
+    EXPECT_TRUE(derivedCRS->isEquivalentTo(derivedCRS.get()));
+    EXPECT_FALSE(derivedCRS->isEquivalentTo(
+        derivedCRS->baseCRS().get(), IComparable::Criterion::EQUIVALENT));
+    EXPECT_FALSE(derivedCRS->baseCRS()->isEquivalentTo(
+        derivedCRS.get(), IComparable::Criterion::EQUIVALENT));
+}
+
+// ---------------------------------------------------------------------------
+
 TEST(crs, derivedGeodeticCRS_WKT2) {
 
     auto expected = "GEODCRS[\"Derived geodetic CRS\",\n"