Fix task can't be cloned if input model was deleted

server/bll/task/task_bll.py

@@ -164,9 +164,11 @@ class TaskBLL(object):
         tags: Optional[Sequence[str]] = None,
         system_tags: Optional[Sequence[str]] = None,
         execution_overrides: Optional[dict] = None,
+        validate_references: bool = False,
     ) -> Task:
         task = cls.get_by_id(company_id=company_id, task_id=task_id)
         execution_dict = task.execution.to_proper_dict() if task.execution else {}
+        execution_model_overriden = False
         if execution_overrides:
             parameters = execution_overrides.get("parameters")
             if parameters is not None:
@@ -174,6 +176,8 @@ class TaskBLL(object):
                     ParameterKeyEscaper.escape(k): v for k, v in parameters.items()
                 }
             execution_dict = deep_merge(execution_dict, execution_overrides)
+            execution_model_overriden = execution_overrides.get("model") is not None
+
         artifacts = execution_dict.get("artifacts")
         if artifacts:
             execution_dict["artifacts"] = [
@@ -201,26 +205,42 @@ class TaskBLL(object):
                 else None,
                 execution=execution_dict,
             )
-            cls.validate(new_task)
+            cls.validate(
+                new_task,
+                validate_model=validate_references or execution_model_overriden,
+                validate_parent=validate_references or parent,
+                validate_project=validate_references or project,
+            )
             new_task.save()
 
         return new_task
 
     @classmethod
-    def validate(cls, task: Task):
-        assert isinstance(task, Task)
-
-        if task.parent and not Task.get(
-            company=task.company, id=task.parent, _only=("id",), include_public=True
+    def validate(
+        cls,
+        task: Task,
+        validate_model=True,
+        validate_parent=True,
+        validate_project=True,
+    ):
+        if (
+            validate_parent
+            and task.parent
+            and not Task.get(
+                company=task.company, id=task.parent, _only=("id",), include_public=True
+            )
         ):
             raise errors.bad_request.InvalidTaskId("invalid parent", parent=task.parent)
 
-        if task.project and not Project.get_for_writing(
-            company=task.company, id=task.project
+        if (
+            validate_project
+            and task.project
+            and not Project.get_for_writing(company=task.company, id=task.project)
         ):
             raise errors.bad_request.InvalidProjectId(id=task.project)
 
-        cls.validate_execution_model(task)
+        if validate_model:
+            cls.validate_execution_model(task)
 
     @staticmethod
     def get_unique_metric_variants(company_id, project_ids=None):