fix: pass reference_doctype to search query methods (#20842)

frappe.call ensures that it's only passed to functions which can accept
it, so nothing to worry about ~ backward compatible change.

frappe/desk/search.py

@@ -81,7 +81,15 @@ def search_widget(
 		try:
 			is_whitelisted(frappe.get_attr(query))
 			frappe.response["values"] = frappe.call(
-				query, doctype, txt, searchfield, start, page_length, filters, as_dict=as_dict
+				query,
+				doctype,
+				txt,
+				searchfield,
+				start,
+				page_length,
+				filters,
+				as_dict=as_dict,
+				reference_doctype=reference_doctype,
 			)
 		except frappe.exceptions.PermissionError as e:
 			if frappe.local.conf.developer_mode:

frappe/tests/test_search.py

@@ -130,12 +130,32 @@ class TestSearch(FrappeTestCase):
 		search_link("User", "user@random", searchfield="name")
 		self.assertListEqual(frappe.response["results"], [])
 
+	def test_reference_doctype(self):
+		"""search query methods should get reference_doctype if they want"""
+		search_link(
+			doctype="User",
+			txt="",
+			filters=None,
+			page_length=20,
+			reference_doctype="ToDo",
+			query="frappe.tests.test_search.query_with_reference_doctype",
+		)
+		self.assertListEqual(frappe.response["results"], [])
+
 
 @frappe.validate_and_sanitize_search_inputs
 def get_data(doctype, txt, searchfield, start, page_len, filters):
 	return [doctype, txt, searchfield, start, page_len, filters]
 
 
+@frappe.whitelist()
+@frappe.validate_and_sanitize_search_inputs
+def query_with_reference_doctype(
+	doctype, txt, searchfield, start, page_len, filters, reference_doctype=None
+):
+	return []
+
+
 def setup_test_link_field_order(TestCase):
 	TestCase.tree_doctype_name = "Test Tree Order"
 	TestCase.child_doctype_list = []