CRS::_isEquivalentTo(): be tolerant to different order of PROJ step options (fixes #2886)

1 files changed, 33 insertions, 0 deletions

diff --git a/test/unit/test_crs.cpp b/test/unit/test_crs.cpp
index a1838896..987ffe1b 100644
--- a/test/unit/test_crs.cpp
+++ b/test/unit/test_crs.cpp
@@ -6726,4 +6726,37 @@ TEST(crs, projected_is_equivalent_to_with_proj4_extension) {
     // Check equivalence of the CRS from PROJ.4 and WKT
     EXPECT_TRUE(crs1->isEquivalentTo(crs_from_wkt.get(),
                                      IComparable::Criterion::EQUIVALENT));
+
+    ASSERT_TRUE(crs_from_wkt != nullptr);
+    // Same as above but with different option order
+    const auto obj2 = PROJStringParser().createFromPROJString(
+        "+proj=omerc +lat_0=50 +no_rot +alpha=50.0 +a=6378144.0 +b=6356759.0 "
+        "+lon_0=8.0 +type=crs");
+    const auto crs2 = nn_dynamic_pointer_cast<ProjectedCRS>(obj2);
+    ASSERT_TRUE(crs2 != nullptr);
+
+    // Check equivalence of the 2 PROJ.4 based CRS
+    EXPECT_TRUE(
+        crs1->isEquivalentTo(crs2.get(), IComparable::Criterion::EQUIVALENT));
+
+    // Without +no_rot --> no PROJ.4 extension
+    const auto objNoRot = PROJStringParser().createFromPROJString(
+        "+proj=omerc +lat_0=50 +alpha=50.0 +a=6378144.0 +b=6356759.0 "
+        "+lon_0=8.0 +type=crs");
+    const auto crsNoRot = nn_dynamic_pointer_cast<ProjectedCRS>(objNoRot);
+    ASSERT_TRUE(crsNoRot != nullptr);
+    EXPECT_FALSE(crs1->isEquivalentTo(crsNoRot.get(),
+                                      IComparable::Criterion::EQUIVALENT));
+    EXPECT_FALSE(crsNoRot->isEquivalentTo(crs1.get(),
+                                          IComparable::Criterion::EQUIVALENT));
+
+    // Change alpha value
+    const auto objDifferent = PROJStringParser().createFromPROJString(
+        "+proj=omerc +lat_0=50 +alpha=49.0 +no_rot +a=6378144.0 +b=6356759.0 "
+        "+lon_0=8.0 +type=crs");
+    const auto crsDifferent =
+        nn_dynamic_pointer_cast<ProjectedCRS>(objDifferent);
+    ASSERT_TRUE(crsDifferent != nullptr);
+    EXPECT_FALSE(crs1->isEquivalentTo(crsDifferent.get(),
+                                      IComparable::Criterion::EQUIVALENT));
 }