import/export PROJ strings from ISO19111 code: require/output +type=crs for CRS objects (refs #1214)

1 files changed, 87 insertions, 59 deletions

diff --git a/src/4D_api.cpp b/src/4D_api.cpp
index ba292262..710b59e3 100644
--- a/src/4D_api.cpp
+++ b/src/4D_api.cpp
@@ -27,6 +27,8 @@
  * DEALINGS IN THE SOFTWARE.
  *****************************************************************************/
 
+#define FROM_PROJ_CPP
+
 #include <errno.h>
 #include <stddef.h>
 #include <stdio.h>
@@ -44,7 +46,9 @@
 
 #include "proj/common.hpp"
 #include "proj/coordinateoperation.hpp"
+#include "proj/internal/internal.hpp"
 
+using namespace NS_PROJ::internal;
 
 /* Initialize PJ_COORD struct */
 PJ_COORD proj_coord (double x, double y, double z, double t) {
@@ -726,6 +730,20 @@ int proj_context_get_use_proj4_init_rules(PJ_CONTEXT *ctx, int from_legacy_code_
     return from_legacy_code_path;
 }
 
+/** Adds a " +type=crs" suffix to a PROJ string (if it is a PROJ string) */
+std::string pj_add_type_crs_if_needed(const std::string& str)
+{
+    std::string ret(str);
+    if( (starts_with(str, "proj=") ||
+            starts_with(str, "+proj=") ||
+            starts_with(str, "+init=") ||
+            starts_with(str, "+title=")) &&
+        str.find("type=crs") == std::string::npos )
+    {
+        ret += " +type=crs";
+    }
+    return ret;
+}
 
 /*****************************************************************************/
 PJ  *proj_create_crs_to_crs (PJ_CONTEXT *ctx, const char *source_crs, const char *target_crs, PJ_AREA *area) {
@@ -763,79 +781,89 @@ PJ  *proj_create_crs_to_crs (PJ_CONTEXT *ctx, const char *source_crs, const char
     const char* const* optionsImportCRS =
         proj_context_get_use_proj4_init_rules(ctx, FALSE) ? optionsProj4Mode : nullptr;
 
-    auto src = proj_create_from_user_input(ctx, source_crs, optionsImportCRS);
-    if( !src ) {
-        proj_context_log_debug(ctx, "Cannot instantiate source_crs");
-        return nullptr;
-    }
+    try
+    {
+        std::string source_crs_modified(pj_add_type_crs_if_needed(source_crs));
+        std::string target_crs_modified(pj_add_type_crs_if_needed(target_crs));
 
-    auto dst = proj_create_from_user_input(ctx, target_crs, optionsImportCRS);
-    if( !dst ) {
-        proj_context_log_debug(ctx, "Cannot instantiate target_crs");
-        proj_destroy(src);
-        return nullptr;
-    }
+        auto src = proj_create_from_user_input(ctx, source_crs_modified.c_str(), optionsImportCRS);
+        if( !src ) {
+            proj_context_log_debug(ctx, "Cannot instantiate source_crs");
+            return nullptr;
+        }
 
-    auto operation_ctx = proj_create_operation_factory_context(ctx, nullptr);
-    if( !operation_ctx ) {
-        proj_destroy(src);
-        proj_destroy(dst);
-        return nullptr;
-    }
+        auto dst = proj_create_from_user_input(ctx, target_crs_modified.c_str(), optionsImportCRS);
+        if( !dst ) {
+            proj_context_log_debug(ctx, "Cannot instantiate target_crs");
+            proj_destroy(src);
+            return nullptr;
+        }
 
-    if( area && area->bbox_set ) {
-        proj_operation_factory_context_set_area_of_interest(
-                                            ctx,
-                                            operation_ctx,
-                                            area->west_lon_degree,
-                                            area->south_lat_degree,
-                                            area->east_lon_degree,
-                                            area->north_lat_degree);
-    }
+        auto operation_ctx = proj_create_operation_factory_context(ctx, nullptr);
+        if( !operation_ctx ) {
+            proj_destroy(src);
+            proj_destroy(dst);
+            return nullptr;
+        }
 
-    proj_operation_factory_context_set_grid_availability_use(
-        ctx, operation_ctx, PROJ_GRID_AVAILABILITY_DISCARD_OPERATION_IF_MISSING_GRID);
+        if( area && area->bbox_set ) {
+            proj_operation_factory_context_set_area_of_interest(
+                                                ctx,
+                                                operation_ctx,
+                                                area->west_lon_degree,
+                                                area->south_lat_degree,
+                                                area->east_lon_degree,
+                                                area->north_lat_degree);
+        }
 
-    auto op_list = proj_create_operations(ctx, src, dst, operation_ctx);
+        proj_operation_factory_context_set_grid_availability_use(
+            ctx, operation_ctx, PROJ_GRID_AVAILABILITY_DISCARD_OPERATION_IF_MISSING_GRID);
 
-    proj_operation_factory_context_destroy(operation_ctx);
-    proj_destroy(src);
-    proj_destroy(dst);
+        auto op_list = proj_create_operations(ctx, src, dst, operation_ctx);
 
-    if( !op_list ) {
-        return nullptr;
-    }
+        proj_operation_factory_context_destroy(operation_ctx);
+        proj_destroy(src);
+        proj_destroy(dst);
 
-    if( proj_list_get_count(op_list) == 0 ) {
+        if( !op_list ) {
+            return nullptr;
+        }
+
+        if( proj_list_get_count(op_list) == 0 ) {
+            proj_list_destroy(op_list);
+            proj_context_log_debug(ctx, "No operation found matching criteria");
+            return nullptr;
+        }
+
+        auto op = proj_list_get(ctx, op_list, 0);
         proj_list_destroy(op_list);
-        proj_context_log_debug(ctx, "No operation found matching criteria");
-        return nullptr;
-    }
+        if( !op ) {
+            return nullptr;
+        }
 
-    auto op = proj_list_get(ctx, op_list, 0);
-    proj_list_destroy(op_list);
-    if( !op ) {
-        return nullptr;
-    }
+        proj_string = proj_as_proj_string(ctx, op, PJ_PROJ_5, nullptr);
+        if( !proj_string) {
+            proj_destroy(op);
+            proj_context_log_debug(ctx, "Cannot export operation as a PROJ string");
+            return nullptr;
+        }
+
+        PJ* P;
+        if( proj_string[0] == '\0' ) {
+            /* Null transform ? */
+            P = proj_create(ctx, "proj=affine");
+        } else {
+            P = proj_create(ctx, proj_string);
+        }
 
-    proj_string = proj_as_proj_string(ctx, op, PJ_PROJ_5, nullptr);
-    if( !proj_string) {
         proj_destroy(op);
-        proj_context_log_debug(ctx, "Cannot export operation as a PROJ string");
-        return nullptr;
-    }
 
-    PJ* P;
-    if( proj_string[0] == '\0' ) {
-        /* Null transform ? */
-        P = proj_create(ctx, "proj=affine");
-    } else {
-        P = proj_create(ctx, proj_string);
+        return P;
+    }
+    catch( const std::exception& )
+    {
+        return nullptr;
     }
-
-    proj_destroy(op);
-
-    return P;
 }
 
 PJ *proj_destroy (PJ *P) {