createFromPROJString(): ignore +no_defs when instanciating a '+init=epsg:xxxx +no_defs' string (related to #1597)

2 files changed, 22 insertions, 4 deletions

diff --git a/src/iso19111/io.cpp b/src/iso19111/io.cpp
index dfe6f6a8..550312d8 100644
--- a/src/iso19111/io.cpp
+++ b/src/iso19111/io.cpp
@@ -8759,10 +8759,17 @@ PROJStringParser::createFromPROJString(const std::string &projString) {
             if (!file_found) {
                 auto obj = createFromUserInput(stepName, d->dbContext_, true);
                 auto crs = dynamic_cast<CRS *>(obj.get());
-                if (crs &&
-                    (d->steps_[0].paramValues.empty() ||
-                     (d->steps_[0].paramValues.size() == 1 &&
-                      d->getParamValue(d->steps_[0], "type") == "crs"))) {
+
+                bool hasSignificantParamValues = false;
+                for (const auto &kv : d->steps_[0].paramValues) {
+                    if (!((kv.key == "type" && kv.value == "crs") ||
+                          kv.key == "no_defs")) {
+                        hasSignificantParamValues = true;
+                        break;
+                    }
+                }
+
+                if (crs && !hasSignificantParamValues) {
                     PropertyMap properties;
                     properties.set(IdentifiedObject::NAME_KEY,
                                    d->title_.empty() ? crs->nameStr()
diff --git a/test/unit/test_io.cpp b/test/unit/test_io.cpp
index 2642ed23..52608a4a 100644
--- a/test/unit/test_io.cpp
+++ b/test/unit/test_io.cpp
@@ -8641,6 +8641,17 @@ TEST(io, projparse_init) {
     }
 
     {
+        // Test that +no_defs +type=crs have no effect
+        auto obj = createFromUserInput("+init=epsg:4326 +no_defs +type=crs",
+                                       dbContext, true);
+        auto crs = nn_dynamic_pointer_cast<GeographicCRS>(obj);
+        ASSERT_TRUE(crs != nullptr);
+
+        auto wkt = crs->exportToWKT(WKTFormatter::create().get());
+        EXPECT_TRUE(wkt.find("GEODCRS[\"WGS 84\"") == 0) << wkt;
+    }
+
+    {
         // EPSG:3040 is normally northing-easting order, but in compatibillity
         // mode it will be easting-northing
         auto obj =