glTF exporter: Fix crash when mesh is not created, without crash

io_scene_gltf2/__init__.py

@@ -15,7 +15,7 @@
 bl_info = {
     'name': 'glTF 2.0 format',
     'author': 'Julien Duroure, Scurest, Norbert Nopper, Urs Hanselmann, Moritz Becher, Benjamin Schmithüsen, Jim Eckerlein, and many external contributors',
-    "version": (1, 6, 14),
+    "version": (1, 6, 15),
     'blender': (2, 91, 0),
     'location': 'File > Import-Export',
     'description': 'Import-Export as glTF 2.0',

io_scene_gltf2/blender/exp/gltf2_blender_gather_nodes.py

@@ -357,6 +357,10 @@ def __gather_mesh_from_nonmesh(blender_object, library, export_settings):
                 blender_mesh_owner = blender_object
                 blender_mesh = blender_mesh_owner.to_mesh()
 
+            # In some cases (for example curve with single vertice), no blender_mesh is created (without crash)
+            if blender_mesh is None:
+                return None
+
         except Exception:
             return None