From bebabc321197b3da45b9378c326468ff09916e5b Mon Sep 17 00:00:00 2001
From: Ankush Menat <ankush@frappe.io>
Date: Tue, 10 Jun 2025 21:57:12 +0530
Subject: [PATCH] fix: Handle support for DocType and virtual

By falling back to original impl with warning.
This is just to allow "fearless usage".
---
 frappe/model/document.py | 27 ++++++++++++++++++---------
 frappe/permissions.py    |  6 ++----
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/frappe/model/document.py b/frappe/model/document.py
index 5134d1fc31..66e917928b 100644
--- a/frappe/model/document.py
+++ b/frappe/model/document.py
@@ -4,6 +4,7 @@ import hashlib
 import itertools
 import json
 import time
+import warnings
 from collections.abc import Generator, Iterable
 from contextlib import contextmanager
 from functools import wraps
@@ -140,7 +141,9 @@ def get_doc_from_dict(data: dict[str, Any], **kwargs) -> "Document":
 
 
 def get_lazy_doc(doctype: str, name: str) -> "Document":
-	assert doctype != "DocType", "DocType can not be lazy loaded"
+	if doctype == "DocType":
+		warnings.warn("DocType doesn't support lazy loading", stacklevel=1)
+		return get_doc(doctype, name)
 
 	controller = get_lazy_controller(doctype)
 	if controller:
@@ -1951,15 +1954,22 @@ def unlock_document(doctype: str, name: str):
 def get_lazy_controller(doctype):
 	lazy_controllers = frappe.lazy_controllers.setdefault(frappe.local.site, {})
 	if doctype not in lazy_controllers:
-		original_controller = get_controller(doctype)
-
-		lazy_controller = type(f"Lazy{original_controller.__name__}", (LazyDocument, original_controller), {})
 		meta = frappe.get_meta(doctype)
-		assert not meta.is_virtual, "Virtual DocTypes can not be lazy loaded"
-		for fieldname, child_doctype in meta._table_doctypes.items():
-			setattr(lazy_controller, fieldname, LazyChildTable(fieldname, child_doctype))
+		original_controller = get_controller(doctype)
+		if meta.is_virtual:  # not supported
+			lazy_controllers[doctype] = original_controller
+			warnings.warn("Virtual doctypes don't support lazy loading", stacklevel=2)
+		else:
+			# Dynamically construct a class that subclasses LazyDocument and original controller.
+			lazy_controller = type(
+				f"Lazy{original_controller.__name__}",
+				(LazyDocument, original_controller),
+				{},
+			)
+			for fieldname, child_doctype in meta._table_doctypes.items():
+				setattr(lazy_controller, fieldname, LazyChildTable(fieldname, child_doctype))
 
-		lazy_controllers[doctype] = lazy_controller
+			lazy_controllers[doctype] = lazy_controller
 	return lazy_controllers[doctype]
 
 
@@ -1971,7 +1981,6 @@ class LazyDocument:
 		"""Override Document which eagerly loads child tables"""
 		# This is a map of loaded children, it should get erased whenever load_children_from_db is
 		# called to allow reloading lazily again.
-		self.flags.lazy_loaded = True
 		for fieldname in self._table_fieldnames:
 			self.__dict__.pop(fieldname, None)
 
diff --git a/frappe/permissions.py b/frappe/permissions.py
index 67b849b82e..21761ba941 100644
--- a/frappe/permissions.py
+++ b/frappe/permissions.py
@@ -129,10 +129,8 @@ def has_permission(
 
 	if doc:
 		if isinstance(doc, str | int):
-			if meta.is_virtual or doctype == "DocType":
-				doc = frappe.get_doc(meta.name, doc)
-			else:  # perf: Avoid loading child tables for perm checks
-				doc = frappe.get_lazy_doc(meta.name, doc)
+			# perf: Avoid loading child tables for perm checks
+			doc = frappe.get_lazy_doc(meta.name, doc)
 		perm = get_doc_permissions(doc, user=user, ptype=ptype, debug=debug).get(ptype)
 		if not perm:
 			debug and _debug_log(