Add proj_create_crs_to_crs_from_pj()

I've been frustrated a number of times with proj_create_crs_to_crs()
not accepting a PJ* object for the source and target CRS.
And thus constraining to go back to WKT2 in a artificial way.

1 files changed, 26 insertions, 0 deletions

diff --git a/test/unit/test_c_api.cpp b/test/unit/test_c_api.cpp
index 74377738..2a1c8577 100644
--- a/test/unit/test_c_api.cpp
+++ b/test/unit/test_c_api.cpp
@@ -3711,4 +3711,30 @@ TEST_F(Fixture_proj_context_set_autoclose_database,
        proj_context_set_autoclose_database_false) {
     test(false);
 }
+
+// ---------------------------------------------------------------------------
+
+TEST_F(CApi, proj_create_crs_to_crs_from_pj) {
+
+    auto src = proj_create(m_ctxt, "EPSG:4326");
+    ObjectKeeper keeper_src(src);
+    ASSERT_NE(src, nullptr);
+
+    auto dst = proj_create(m_ctxt, "EPSG:32631");
+    ObjectKeeper keeper_dst(dst);
+    ASSERT_NE(dst, nullptr);
+
+    auto P = proj_create_crs_to_crs_from_pj(m_ctxt, src, dst, nullptr, nullptr);
+    ObjectKeeper keeper_P(P);
+    ASSERT_NE(P, nullptr);
+    auto Pnormalized = proj_normalize_for_visualization(m_ctxt, P);
+    ObjectKeeper keeper_Pnormalized(Pnormalized);
+    ASSERT_NE(Pnormalized, nullptr);
+    auto projstr = proj_as_proj_string(m_ctxt, Pnormalized, PJ_PROJ_5, nullptr);
+    ASSERT_NE(projstr, nullptr);
+    EXPECT_EQ(std::string(projstr),
+              "+proj=pipeline +step +proj=unitconvert +xy_in=deg +xy_out=rad "
+              "+step +proj=utm +zone=31 +ellps=WGS84");
+}
+
 } // namespace