ENH: Added proj_context_clone

.gitignore

@@ -134,6 +134,7 @@ m4/lt~obsolete.m4
 /test/unit/proj_errno_string_test
 /test/unit/test_defmodel
 /test/unit/test_network
+/test/unit/test_tinshift
 /tmp_alias/
 
 # jniwrap

docs/source/development/reference/functions.rst

@@ -13,6 +13,14 @@ Threading contexts
 
     :returns: a new context
 
+.. c:function:: PJ_CONTEXT* proj_context_clone(PJ_CONTEXT *ctx)
+
+    .. versionadded:: 7.2
+
+    Create a new threading-context based on an existing context.
+
+    :returns: a new context
+
 .. c:function:: void proj_context_destroy(PJ_CONTEXT *ctx)
 
     Deallocate a threading-context.

scripts/reference_exported_symbols.txt

@@ -752,6 +752,7 @@ pj_compare_datums
 pj_context_get_grid_cache_filename(projCtx_t*)
 pj_context_set_user_writable_directory(projCtx_t*, std::string const&)
 pj_ctx_alloc
+pj_ctx_clone
 pj_ctx_fclose
 pj_ctx_fgets
 pj_ctx_fopen
@@ -830,6 +831,7 @@ proj_cleanup
 proj_clone
 proj_concatoperation_get_step
 proj_concatoperation_get_step_count
+proj_context_clone
 proj_context_create
 proj_context_delete_cpp_context(projCppContext*)
 proj_context_destroy

src/4D_api.cpp

@@ -1448,11 +1448,18 @@ int proj_errno_reset (const PJ *P) {
 }
 
 
-/* Create a new context */
+/* Create a new context based on the default context */
 PJ_CONTEXT *proj_context_create (void) {
     return pj_ctx_alloc ();
 }
 
+/* Create a new context based on a custom context */
+PJ_CONTEXT *proj_context_clone (PJ_CONTEXT *ctx) {
+    if (nullptr==ctx)
+        return pj_ctx_alloc ();
+
+    return pj_ctx_clone (ctx);
+}
 
 PJ_CONTEXT *proj_context_destroy (PJ_CONTEXT *ctx) {
     if (nullptr==ctx)

src/ctx.cpp

@@ -225,6 +225,16 @@ projCtx pj_ctx_alloc()
     return new (std::nothrow) projCtx_t(*pj_get_default_ctx());
 }
 
+/************************************************************************/
+/*                            pj_ctx_clone()                            */
+/************************************************************************/
+
+projCtx pj_ctx_clone( projCtx ctx )
+
+{
+    return new (std::nothrow) projCtx_t(*ctx);
+}
+
 /************************************************************************/
 /*                            pj_ctx_free()                             */
 /************************************************************************/

src/proj.h

@@ -361,6 +361,7 @@ typedef struct projCtx_t PJ_CONTEXT;
 #endif
 PJ_CONTEXT PROJ_DLL *proj_context_create (void);
 PJ_CONTEXT PROJ_DLL *proj_context_destroy (PJ_CONTEXT *ctx);
+PJ_CONTEXT PROJ_DLL *proj_context_clone (PJ_CONTEXT *ctx);
 
 /** Callback to resolve a filename to a full path */
 typedef const char* (*proj_file_finder) (PJ_CONTEXT *ctx, const char*, void* user_data);

src/proj_api.h

@@ -192,6 +192,7 @@ void PROJ_DLL pj_cleanup_lock(void);
 
 void PROJ_DLL pj_set_ctx( projPJ, projCtx );
 projCtx PROJ_DLL pj_ctx_alloc(void);
+projCtx PROJ_DLL pj_ctx_clone( projCtx );
 void    PROJ_DLL pj_ctx_free( projCtx );
 int PROJ_DLL pj_ctx_get_errno( projCtx );
 void PROJ_DLL pj_ctx_set_errno( projCtx, int );

src/proj_symbol_rename.h

@@ -29,6 +29,7 @@
 #define pj_clear_initcache internal_pj_clear_initcache
 #define pj_compare_datums internal_pj_compare_datums
 #define pj_ctx_alloc internal_pj_ctx_alloc
+#define pj_ctx_clone internal_pj_ctx_clone
 #define pj_ctx_fclose internal_pj_ctx_fclose
 #define pj_ctx_fgets internal_pj_ctx_fgets
 #define pj_ctx_fopen internal_pj_ctx_fopen
@@ -97,6 +98,7 @@
 #define proj_clone internal_proj_clone
 #define proj_concatoperation_get_step internal_proj_concatoperation_get_step
 #define proj_concatoperation_get_step_count internal_proj_concatoperation_get_step_count
+#define proj_context_clone internal_proj_context_clone
 #define proj_context_create internal_proj_context_create
 #define proj_context_destroy internal_proj_context_destroy
 #define proj_context_errno internal_proj_context_errno
@@ -235,6 +237,8 @@
 #define proj_crs_get_coordinate_system internal_proj_crs_get_coordinate_system
 #define proj_crs_get_coordoperation internal_proj_crs_get_coordoperation
 #define proj_crs_get_datum internal_proj_crs_get_datum
+#define proj_crs_get_datum_ensemble internal_proj_crs_get_datum_ensemble
+#define proj_crs_get_datum_forced internal_proj_crs_get_datum_forced
 #define proj_crs_get_geodetic_crs internal_proj_crs_get_geodetic_crs
 #define proj_crs_get_horizontal_datum internal_proj_crs_get_horizontal_datum
 #define proj_crs_get_sub_crs internal_proj_crs_get_sub_crs
@@ -243,11 +247,15 @@
 #define proj_cs_get_axis_count internal_proj_cs_get_axis_count
 #define proj_cs_get_axis_info internal_proj_cs_get_axis_info
 #define proj_cs_get_type internal_proj_cs_get_type
+#define proj_datum_ensemble_get_accuracy internal_proj_datum_ensemble_get_accuracy
+#define proj_datum_ensemble_get_member internal_proj_datum_ensemble_get_member
+#define proj_datum_ensemble_get_member_count internal_proj_datum_ensemble_get_member_count
 #define proj_degree_input internal_proj_degree_input
 #define proj_degree_output internal_proj_degree_output
 #define proj_destroy internal_proj_destroy
 #define proj_dmstor internal_proj_dmstor
 #define proj_download_file internal_proj_download_file
+#define proj_dynamic_datum_get_frame_reference_epoch internal_proj_dynamic_datum_get_frame_reference_epoch
 #define proj_ellipsoid_get_parameters internal_proj_ellipsoid_get_parameters
 #define proj_errno internal_proj_errno
 #define proj_errno_reset internal_proj_errno_reset

test/unit/test_c_api.cpp

@@ -4073,7 +4073,7 @@ TEST_F(Fixture_proj_context_set_autoclose_database,
 
 // ---------------------------------------------------------------------------
 
-TEST_F(CApi, proj_context_clone) {
+TEST_F(CApi, proj_context_copy_from_default) {
     auto c_path = proj_context_get_database_path(m_ctxt);
     ASSERT_TRUE(c_path != nullptr);
     std::string path(c_path);
@@ -4123,6 +4123,28 @@ TEST_F(CApi, proj_context_clone) {
     ASSERT_EQ(new_db_path, tmp_filename);
 }
 
+
+// ---------------------------------------------------------------------------
+
+TEST_F(CApi, proj_context_clone) {
+    int new_init_rules = proj_context_get_use_proj4_init_rules(NULL, 0) > 0 ? 0 : 1;
+    PJ_CONTEXT *new_ctx = proj_context_create();
+    EXPECT_NE(new_ctx, nullptr);
+    PjContextKeeper keeper_ctxt(new_ctx);
+    proj_context_use_proj4_init_rules(new_ctx, new_init_rules);
+    PJ_CONTEXT *clone_ctx = proj_context_clone(new_ctx);
+    EXPECT_NE(clone_ctx, nullptr);
+    PjContextKeeper keeper_clone_ctxt(clone_ctx);
+    ASSERT_EQ(
+        proj_context_get_use_proj4_init_rules(new_ctx, 0),
+        proj_context_get_use_proj4_init_rules(clone_ctx, 0)
+    );
+    EXPECT_NE(
+        proj_context_get_use_proj4_init_rules(NULL, 0),
+        proj_context_get_use_proj4_init_rules(clone_ctx, 0)
+    );
+}
+
 // ---------------------------------------------------------------------------
 
 TEST_F(CApi, proj_create_crs_to_crs_from_pj) {