fix: Test for Over Receipt via PRs on a PO
diff --git a/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py b/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py
index 4a8236d..67161aa 100644
--- a/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py
+++ b/erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py
@@ -3,6 +3,7 @@
 
 from __future__ import unicode_literals
 import unittest
+import json
 import frappe, erpnext
 import frappe.defaults
 from frappe.utils import cint, flt, cstr, today, random_string
@@ -152,13 +153,78 @@
 			qty=100, basic_rate=100, company="_Test Company with perpetual inventory")
 		pr = make_purchase_receipt(item_code="_Test FG Item", qty=10, rate=0, is_subcontracted="Yes",
 			company="_Test Company with perpetual inventory", warehouse='Stores - TCP1', supplier_warehouse='Work In Progress - TCP1')
-		
+
 		gl_entries = get_gl_entries("Purchase Receipt", pr.name)
 
 		self.assertFalse(gl_entries)
 
 		set_perpetual_inventory(0)
 
+	def test_subcontracting_over_receipt(self):
+		"""
+			Behaviour: Raise multiple PRs against one PO that in total
+				receive more than the required qty in the PO.
+			Expected Result: Error Raised for Over Receipt against PO.
+		"""
+		from erpnext.stock.doctype.stock_entry.test_stock_entry import make_stock_entry
+		from erpnext.buying.doctype.purchase_order.test_purchase_order import (update_backflush_based_on,
+			make_subcontracted_item, create_purchase_order)
+		from erpnext.buying.doctype.purchase_order.purchase_order import (make_purchase_receipt,
+			make_rm_stock_entry as make_subcontract_transfer_entry)
+
+		update_backflush_based_on("Material Transferred for Subcontract")
+		item_code = "_Test Subcontracted FG Item 1"
+		make_subcontracted_item(item_code)
+
+		po = create_purchase_order(item_code=item_code, qty=1,
+			is_subcontracted="Yes", supplier_warehouse="_Test Warehouse 1 - _TC")
+
+		#stock raw materials in a warehouse before transfer
+		make_stock_entry(target="_Test Warehouse - _TC",
+			item_code="_Test Item Home Desktop 100", qty=1, basic_rate=100)
+		make_stock_entry(target="_Test Warehouse - _TC",
+			item_code = "Test Extra Item 1", qty=1, basic_rate=100)
+		make_stock_entry(target="_Test Warehouse - _TC",
+			item_code = "_Test Item", qty=1, basic_rate=100)
+
+		rm_items = [
+			{
+				"item_code": item_code,
+				"rm_item_code": po.supplied_items[0].rm_item_code,
+				"item_name": "_Test Item",
+				"qty": po.supplied_items[0].required_qty,
+				"warehouse": "_Test Warehouse - _TC",
+				"stock_uom": "Nos"
+			},
+			{
+				"item_code": item_code,
+				"rm_item_code": po.supplied_items[1].rm_item_code,
+				"item_name": "Test Extra Item 1",
+				"qty": po.supplied_items[1].required_qty,
+				"warehouse": "_Test Warehouse - _TC",
+				"stock_uom": "Nos"
+			},
+			{
+				"item_code": item_code,
+				"rm_item_code": po.supplied_items[2].rm_item_code,
+				"item_name": "_Test Item Home Desktop 100",
+				"qty": po.supplied_items[2].required_qty,
+				"warehouse": "_Test Warehouse - _TC",
+				"stock_uom": "Nos"
+			}
+		]
+		rm_item_string = json.dumps(rm_items)
+		se = frappe.get_doc(make_subcontract_transfer_entry(po.name, rm_item_string))
+		se.to_warehouse = "_Test Warehouse 1 - _TC"
+		se.save()
+		se.submit()
+
+		pr1 = make_purchase_receipt(po.name)
+		pr2 = make_purchase_receipt(po.name)
+
+		pr1.submit()
+		self.assertRaises(frappe.ValidationError, pr2.submit)
+
 	def test_serial_no_supplier(self):
 		pr = make_purchase_receipt(item_code="_Test Serialized Item With Series", qty=1)
 		self.assertEqual(frappe.db.get_value("Serial No", pr.get("items")[0].serial_no, "supplier"),