fix: validate installation note rows against the delivery note

erpnext/selling/doctype/installation_note/installation_note.py

@@ -4,7 +4,7 @@
 
 import frappe
 from frappe import _
-from frappe.utils import cstr, getdate
+from frappe.utils import cstr, escape_html, getdate
 
 from erpnext.stock.utils import get_valid_serial_nos
 from erpnext.utilities.transaction_base import TransactionBase
@@ -65,11 +65,53 @@ class InstallationNote(TransactionBase):
 	def validate(self):
 		self.validate_installation_date()
 		self.check_item_table()
+		self.validate_with_previous_doc()
 
 		from erpnext.controllers.selling_controller import set_default_income_account_for_item
 
 		set_default_income_account_for_item(self)
 
+	def validate_with_previous_doc(self):
+		self.validate_prevdoc_references()
+		super().validate_with_previous_doc(
+			{
+				"Delivery Note": {
+					"ref_dn_field": "prevdoc_docname",
+					"compare_fields": [["customer", "="], ["company", "="]],
+				},
+				"Delivery Note Item": {
+					"ref_dn_field": "prevdoc_detail_docname",
+					"compare_fields": [["item_code", "="]],
+					"is_child_table": True,
+					"allow_duplicate_prev_row_id": True,
+				},
+			}
+		)
+
+	def validate_prevdoc_references(self):
+		for d in self.get("items"):
+			if not d.prevdoc_detail_docname:
+				continue
+
+			dn_item = frappe.db.get_value(
+				"Delivery Note Item", d.prevdoc_detail_docname, ["parent", "docstatus"], as_dict=True
+			)
+			if not dn_item or dn_item.docstatus != 1:
+				frappe.throw(
+					_("Row #{0}: Installation can only be recorded against a submitted Delivery Note").format(
+						d.idx
+					)
+				)
+
+			# the referenced row must belong to the named Delivery Note, else a submit could
+			# update an unrelated customer's Delivery Note row
+			if dn_item.parent != d.prevdoc_docname:
+				frappe.throw(
+					_("Row #{0}: Delivery Note Item does not belong to Delivery Note {1}").format(
+						d.idx, escape_html(cstr(d.prevdoc_docname))
+					)
+				)
+
 	def is_serial_no_added(self, item_code, serial_no):
 		has_serial_no = frappe.db.get_value("Item", item_code, "has_serial_no")
 		if has_serial_no == 1 and not serial_no:

erpnext/selling/doctype/installation_note/test_installation_note.py

@@ -1,10 +1,43 @@
 # Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
 # See license.txt
 
-import unittest
+import frappe
+from frappe.tests.utils import FrappeTestCase
+from frappe.utils import nowdate
 
-# test_records = frappe.get_test_records('Installation Note')
+from erpnext.stock.doctype.delivery_note.delivery_note import make_installation_note
+from erpnext.stock.doctype.delivery_note.test_delivery_note import create_delivery_note
+from erpnext.stock.doctype.item.test_item import make_item
 
 
-class TestInstallationNote(unittest.TestCase):
-	pass
+class TestInstallationNote(FrappeTestCase):
+	def setUp(self):
+		frappe.db.set_single_value("Stock Settings", "allow_negative_stock", 1)
+
+	def test_item_must_match_delivery_note_row(self):
+		dn = create_delivery_note(qty=5)
+		note = make_installation_note(dn.name)
+		note.inst_date = nowdate()
+		note.items[0].item_code = make_item(properties={"is_stock_item": 0}).name
+
+		self.assertRaises(frappe.ValidationError, note.insert)
+
+	def test_cannot_install_against_cancelled_delivery_note(self):
+		dn = create_delivery_note(qty=5)
+		note = make_installation_note(dn.name)
+		note.inst_date = nowdate()
+		note.insert()
+
+		dn.cancel()
+
+		self.assertRaises(frappe.ValidationError, note.submit)
+
+	def test_cannot_install_against_foreign_delivery_row(self):
+		own = create_delivery_note(qty=5)
+		foreign = create_delivery_note(qty=5, customer="_Test Customer 1")
+
+		note = make_installation_note(own.name)
+		note.inst_date = nowdate()
+		note.items[0].prevdoc_detail_docname = foreign.items[0].name
+
+		self.assertRaises(frappe.ValidationError, note.insert)