Merge pull request #2808 from OSGeo/backport-2807-to-8.1

[Backport 8.1] createOperations(): fix missing deg<-->rad conversion when transforming with a CRS that has a fallback-to-PROJ4-string behaviour and is a BoundCRS of a GeographicCRS (fixes #2804)

2 files changed, 28 insertions, 2 deletions

diff --git a/src/iso19111/operation/coordinateoperationfactory.cpp b/src/iso19111/operation/coordinateoperationfactory.cpp
index d63db19e..fc64bd2e 100644
--- a/src/iso19111/operation/coordinateoperationfactory.cpp
+++ b/src/iso19111/operation/coordinateoperationfactory.cpp
@@ -3121,7 +3121,8 @@ void CoordinateOperationFactory::Private::createOperationsFromProj4Ext(
     projFormatter->setLegacyCRSToCRSContext(true);
     projFormatter->startInversion();
     sourceProjExportable->_exportToPROJString(projFormatter.get());
-    auto geogSrc = dynamic_cast<const crs::GeographicCRS *>(sourceCRS.get());
+    auto geogSrc = dynamic_cast<const crs::GeographicCRS *>(
+        boundSrc ? boundSrc->baseCRS().get() : sourceCRS.get());
     if (geogSrc) {
         auto tmpFormatter = io::PROJStringFormatter::create();
         geogSrc->addAngularUnitConvertAndAxisSwap(tmpFormatter.get());
@@ -3131,7 +3132,8 @@ void CoordinateOperationFactory::Private::createOperationsFromProj4Ext(
     projFormatter->stopInversion();
 
     targetProjExportable->_exportToPROJString(projFormatter.get());
-    auto geogDst = dynamic_cast<const crs::GeographicCRS *>(targetCRS.get());
+    auto geogDst = dynamic_cast<const crs::GeographicCRS *>(
+        boundDst ? boundDst->baseCRS().get() : targetCRS.get());
     if (geogDst) {
         auto tmpFormatter = io::PROJStringFormatter::create();
         geogDst->addAngularUnitConvertAndAxisSwap(tmpFormatter.get());
diff --git a/test/unit/test_operationfactory.cpp b/test/unit/test_operationfactory.cpp
index 47c6636c..56d9f743 100644
--- a/test/unit/test_operationfactory.cpp
+++ b/test/unit/test_operationfactory.cpp
@@ -6108,6 +6108,30 @@ TEST(operation, createOperation_fallback_to_proj4_strings) {
 
 // ---------------------------------------------------------------------------
 
+TEST(operation, createOperation_fallback_to_proj4_strings_bound_of_geog) {
+    auto objSrc = PROJStringParser().createFromPROJString(
+        "+proj=longlat +geoc +ellps=GRS80 +towgs84=0,0,0 +type=crs");
+    auto src = nn_dynamic_pointer_cast<BoundCRS>(objSrc);
+    ASSERT_TRUE(src != nullptr);
+
+    auto objDest = PROJStringParser().createFromPROJString(
+        "+proj=longlat +geoc +ellps=clrk66 +towgs84=0,0,0 +type=crs");
+    auto dest = nn_dynamic_pointer_cast<BoundCRS>(objDest);
+    ASSERT_TRUE(dest != nullptr);
+
+    auto op = CoordinateOperationFactory::create()->createOperation(
+        NN_CHECK_ASSERT(src), NN_CHECK_ASSERT(dest));
+    ASSERT_TRUE(op != nullptr);
+    EXPECT_EQ(op->exportToPROJString(PROJStringFormatter::create().get()),
+              "+proj=pipeline "
+              "+step +proj=unitconvert +xy_in=deg +xy_out=rad "
+              "+step +inv +proj=longlat +geoc +ellps=GRS80 +towgs84=0,0,0 "
+              "+step +proj=longlat +geoc +ellps=clrk66 +towgs84=0,0,0 "
+              "+step +proj=unitconvert +xy_in=rad +xy_out=deg");
+}
+
+// ---------------------------------------------------------------------------
+
 TEST(
     operation,
     createOperation_fallback_to_proj4_strings_regular_with_datum_to_projliteral) {