diff --git a/erpnext/controllers/stock_controller.py b/erpnext/controllers/stock_controller.py
index 92f8ff0..9be5c0d 100644
--- a/erpnext/controllers/stock_controller.py
+++ b/erpnext/controllers/stock_controller.py
@@ -3,6 +3,7 @@
 
 import json
 from collections import defaultdict
+from typing import List, Tuple
 
 import frappe
 from frappe import _
@@ -181,33 +182,28 @@
 
 			return details
 
-	def get_items_and_warehouses(self):
-		items, warehouses = [], []
+	def get_items_and_warehouses(self) -> Tuple[List[str], List[str]]:
+		"""Get list of items and warehouses affected by a transaction"""
 
-		if hasattr(self, "items") or hasattr(self, "packed_items"):
-			item_doclist = (self.get("items") or []) + (self.get("packed_items") or [])
-		elif self.doctype == "Stock Reconciliation":
-			item_doclist = []
-			data = json.loads(self.reconciliation_json)
-			for row in data[data.index(self.head_row)+1:]:
-				d = frappe._dict(zip(["item_code", "warehouse", "qty", "valuation_rate"], row))
-				item_doclist.append(d)
+		if not (hasattr(self, "items") or hasattr(self, "packed_items")):
+			return [], []
 
-		if item_doclist:
-			for d in item_doclist:
-				if d.item_code and d.item_code not in items:
-					items.append(d.item_code)
+		item_rows = (self.get("items") or []) + (self.get("packed_items") or [])
 
-				if d.get("warehouse") and d.warehouse not in warehouses:
-					warehouses.append(d.warehouse)
+		items = {d.item_code for d in item_rows if d.item_code}
 
-				if self.doctype == "Stock Entry":
-					if d.get("s_warehouse") and d.s_warehouse not in warehouses:
-						warehouses.append(d.s_warehouse)
-					if d.get("t_warehouse") and d.t_warehouse not in warehouses:
-						warehouses.append(d.t_warehouse)
+		warehouses = set()
+		for d in item_rows:
+			if d.get("warehouse"):
+				warehouses.add(d.warehouse)
 
-		return items, warehouses
+			if self.doctype == "Stock Entry":
+				if d.get("s_warehouse"):
+					warehouses.add(d.s_warehouse)
+				if d.get("t_warehouse"):
+					warehouses.add(d.t_warehouse)
+
+		return list(items), list(warehouses)
 
 	def get_stock_ledger_details(self):
 		stock_ledger = {}