fix: Return empty result if no perm level access (backport #24591) (#…

…24592)

* fix: Return empty result if no perm level access (#24591)

(cherry picked from commit 3bea50d)

# Conflicts:
#	frappe/tests/test_db_query.py

* chore: conflicts

---------

Co-authored-by: Ankush Menat <ankush@frappe.io>

frappe/model/db_query.py

@@ -216,6 +216,10 @@ def build_and_run(self):
 		args = self.prepare_args()
 		args.limit = self.add_limit()
 
+		if not args.fields:
+			# apply_fieldlevel_read_permissions has likely removed ALL the fields that user asked for
+			return []
+
 		if args.conditions:
 			args.conditions = "where " + args.conditions