fix T42022 Attempt to export empty set of objects resulted in an exception

2 files changed, 45 insertions, 30 deletions

diff --git a/source/blender/collada/collada.cpp b/source/blender/collada/collada.cpp
index 223ab3eca2a..ffbbb8623ac 100644
--- a/source/blender/collada/collada.cpp
+++ b/source/blender/collada/collada.cpp
@@ -111,16 +111,28 @@ int collada_export(Scene *sce,
 
 	eObjectSet objectSet = (export_settings.selected) ? OB_SET_SELECTED : OB_SET_ALL;
 	export_settings.export_set = BKE_object_relational_superset(sce, objectSet, (eObRelationTypes)includeFilter);
-
-	if (export_settings.sort_by_name)
-		bc_bubble_sort_by_Object_name(export_settings.export_set);
+	int export_count = BLI_linklist_length(export_settings.export_set);
+
+	if (export_count==0)
+	{
+		if (export_settings.selected) {
+			fprintf(stderr, "Collada: Found no objects to export.\nPlease ensure that all objects which shall be exported are also visible in the 3D Viewport.\n");
+		}
+		else{
+			fprintf(stderr, "Collada: Your scene seems to be empty. No Objects will be exported.\n");
+		}
+	}
+	else {
+		if (export_settings.sort_by_name)
+			bc_bubble_sort_by_Object_name(export_settings.export_set);
+	}
 
 	DocumentExporter exporter(&export_settings);
 	exporter.exportCurrentScene(sce);
 
 	BLI_linklist_free(export_settings.export_set, NULL);
 
-	return 1;
+	return export_count;
 }
 
 /* end extern C */
diff --git a/source/blender/editors/io/io_collada.c b/source/blender/editors/io/io_collada.c
index a4130540b1b..bc23c2db433 100644
--- a/source/blender/editors/io/io_collada.c
+++ b/source/blender/editors/io/io_collada.c
@@ -148,33 +148,36 @@ static int wm_collada_export_exec(bContext *C, wmOperator *op)
 	ED_object_editmode_load(CTX_data_edit_object(C));
 
 
-
-	if (collada_export(CTX_data_scene(C),
-	                   filepath,
-	                   apply_modifiers,
-	                   export_mesh_type,
-	                   selected,
-	                   include_children,
-	                   include_armatures,
-	                   include_shapekeys,
-	                   deform_bones_only,
-
-	                   active_uv_only,
-	                   include_uv_textures,
-	                   include_material_textures,
-	                   use_texture_copies,
-
-	                   triangulate,
-	                   use_object_instantiation,
-	                   sort_by_name,
-	                   export_transformation_type,
-	                   open_sim))
-	{
-		return OPERATOR_FINISHED;
-	}
-	else {
-		BKE_report(op->reports, RPT_WARNING, "Export file not created");
+	int export_count = collada_export(CTX_data_scene(C),
+		filepath,
+		apply_modifiers,
+		export_mesh_type,
+		selected,
+		include_children,
+		include_armatures,
+		include_shapekeys,
+		deform_bones_only,
+
+		active_uv_only,
+		include_uv_textures,
+		include_material_textures,
+		use_texture_copies,
+
+		triangulate,
+		use_object_instantiation,
+		sort_by_name,
+		export_transformation_type,
+		open_sim);
+
+	if(export_count == 0) {
+		BKE_report(op->reports, RPT_WARNING, "Export file is empty");
 		return OPERATOR_CANCELLED;
+		}
+	else {
+		char buff[100];
+		sprintf(buff, "Exported %d Objects", export_count);
+		BKE_report(op->reports, RPT_INFO, buff);
+		return OPERATOR_FINISHED;
 	}
 }