Fix #147270: Smooth by angle asset detection broken

Previous attempts:
- 6d884e0da5
- 80e8493c11

It seems `BLI_path_normalize` was doing more than necessary and that
was getting in the way. This PR adds an automated test to avoid the issue
in the future.

Pull Request: https://projects.blender.org/blender/blender/pulls/148069

source/blender/editors/object/object_edit.cc

@@ -12,6 +12,7 @@
 #include <cstring>
 #include <ctime>
 
+#include "AS_asset_library.hh"
 #include "BLI_path_utils.hh"
 #include "MEM_guardedalloc.h"
 
@@ -1664,7 +1665,7 @@ static bool is_smooth_by_angle_modifier(const ModifierData &md)
     return false;
   }
   char auto_smooth_asset_path[FILE_MAX] = "datafiles/assets/nodes/geometry_nodes_essentials.blend";
-  BLI_path_normalize(auto_smooth_asset_path);
+  BLI_path_slash_native(auto_smooth_asset_path);
   if (!StringRef(library->filepath).endswith(auto_smooth_asset_path)) {
     return false;
   }
@@ -1885,6 +1886,12 @@ static wmOperatorStatus shade_auto_smooth_exec(bContext *C, wmOperator *op)
     asset_weak_ref.relative_asset_identifier = BLI_strdup(
         "nodes/geometry_nodes_essentials.blend/NodeTree/Smooth by Angle");
 
+    if (G.background) {
+      /* For testing purposes, make sure assets are loaded (this make take too long to do
+       * automatically during user interaction). */
+      asset::list::storage_fetch_blocking(asset_system::all_library_reference(), *C);
+    }
+
     const asset_system::AssetRepresentation *asset_representation =
         asset::find_asset_from_weak_ref(*C, asset_weak_ref, op->reports);
     if (!asset_representation) {

tests/python/CMakeLists.txt

@@ -410,6 +410,11 @@ if(TEST_SRC_DIR_EXISTS)
     --python ${TEST_PYTHON_DIR}/mesh_join.py
   )
 
+  add_blender_test(
+    object_edit
+    --python ${TEST_PYTHON_DIR}/object_edit.py
+  )
+
   add_blender_test(
     object_conversion
     ${TEST_SRC_DIR}/modeling/object_conversion.blend

tests/python/object_edit.py

@@ -0,0 +1,39 @@
+# SPDX-FileCopyrightText: 2025 Blender Authors
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+
+import unittest
+import bpy
+import sys
+
+
+class TestObjectEdit(unittest.TestCase):
+
+    def setUp(self):
+        if bpy.context.object and bpy.context.object.mode != 'OBJECT':
+            bpy.ops.object.mode_set(mode='OBJECT')
+        for mesh in [mesh for mesh in bpy.data.meshes]:
+            bpy.data.meshes.remove(mesh)
+        for ob in [ob for ob in bpy.data.objects]:
+            bpy.data.objects.remove(ob)
+
+    def test_auto_smooth_detection(self):
+        bpy.ops.mesh.primitive_cube_add()
+        ob = bpy.context.object
+        bpy.ops.object.shade_auto_smooth(use_auto_smooth=True)
+        bpy.ops.object.shade_auto_smooth(use_auto_smooth=True)
+        bpy.ops.object.shade_auto_smooth(use_auto_smooth=True)
+        bpy.ops.object.shade_auto_smooth(use_auto_smooth=True)
+        self.assertEqual(len(ob.modifiers), 1)
+        bpy.ops.object.shade_flat()
+        self.assertEqual(len(ob.modifiers), 0)
+        bpy.ops.object.shade_auto_smooth(use_auto_smooth=True)
+        bpy.ops.object.shade_smooth()
+        self.assertEqual(len(ob.modifiers), 0)
+
+
+if __name__ == '__main__':
+    import sys
+    sys.argv = [__file__] + (sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else [])
+    unittest.main()