fix: negative qty validation on stock reco cancellation (#27170)

* test: negative stock validation on SR cancel

* fix: negative stock setting ignored in stock reco

In stock reconcilation cancellation negative stock setting is ignored as
`db.get_value` is returning string `'0'` which is not casted to int/bool
for further logic. This causes negative qty, which evantually gets
caught by reposting but by design this should stop cancellation.

* test: typo and minor refactor

erpnext/stock/doctype/stock_reconciliation/stock_reconciliation.py

@@ -390,7 +390,7 @@ class StockReconciliation(StockController):
 				sl_entries = self.merge_similar_item_serial_nos(sl_entries)
 
 			sl_entries.reverse()
-			allow_negative_stock = frappe.db.get_value("Stock Settings", None, "allow_negative_stock")
+			allow_negative_stock = cint(frappe.db.get_single_value("Stock Settings", "allow_negative_stock"))
 			self.make_sl_entries(sl_entries, allow_negative_stock=allow_negative_stock)
 
 

erpnext/stock/doctype/stock_reconciliation/test_stock_reconciliation.py

@@ -15,6 +15,7 @@ from erpnext.stock.doctype.item.test_item import create_item
 from erpnext.stock.utils import get_incoming_rate, get_stock_value_on, get_valuation_method
 from erpnext.stock.doctype.serial_no.serial_no import get_serial_nos
 from erpnext.stock.doctype.purchase_receipt.test_purchase_receipt import make_purchase_receipt
+from erpnext.tests.utils import change_settings
 
 
 class TestStockReconciliation(unittest.TestCase):
@@ -310,6 +311,7 @@ class TestStockReconciliation(unittest.TestCase):
 		pr2.cancel()
 		pr1.cancel()
 
+	@change_settings("Stock Settings", {"allow_negative_stock": 0})
 	def test_backdated_stock_reco_future_negative_stock(self):
 		"""
 			Test if a backdated stock reco causes future negative stock and is blocked.
@@ -327,8 +329,6 @@ class TestStockReconciliation(unittest.TestCase):
 		warehouse = "_Test Warehouse - _TC"
 		create_item(item_code)
 
-		negative_stock_setting = frappe.db.get_single_value("Stock Settings", "allow_negative_stock")
-		frappe.db.set_value("Stock Settings", None, "allow_negative_stock", 0)
 
 		pr1 = make_purchase_receipt(item_code=item_code, warehouse=warehouse, qty=10, rate=100,
 			posting_date=add_days(nowdate(), -2))
@@ -348,11 +348,50 @@ class TestStockReconciliation(unittest.TestCase):
 		self.assertRaises(NegativeStockError, sr3.submit)
 
 		# teardown
-		frappe.db.set_value("Stock Settings", None, "allow_negative_stock", negative_stock_setting)
 		sr3.cancel()
 		dn2.cancel()
 		pr1.cancel()
 
+
+	@change_settings("Stock Settings", {"allow_negative_stock": 0})
+	def test_backdated_stock_reco_cancellation_future_negative_stock(self):
+		"""
+			Test if a backdated stock reco cancellation that causes future negative stock is blocked.
+			-------------------------------------------
+			Var | Doc  | Qty | Balance
+			-------------------------------------------
+			SR  | Reco | 100 | 100     (posting date: today-1) (shouldn't be cancelled after DN)
+			DN  | DN   | 100 |   0     (posting date: today)
+		"""
+		from erpnext.stock.stock_ledger import NegativeStockError
+		from erpnext.stock.doctype.delivery_note.test_delivery_note import create_delivery_note
+		frappe.db.commit()
+
+		item_code = "Backdated-Reco-Cancellation-Item"
+		warehouse = "_Test Warehouse - _TC"
+		create_item(item_code)
+
+
+		sr = create_stock_reconciliation(item_code=item_code, warehouse=warehouse, qty=100, rate=100,
+			posting_date=add_days(nowdate(), -1))
+
+		dn = create_delivery_note(item_code=item_code, warehouse=warehouse, qty=100, rate=120,
+			posting_date=nowdate())
+
+		dn_balance = frappe.db.get_value("Stock Ledger Entry", {"voucher_no": dn.name, "is_cancelled": 0},
+			"qty_after_transaction")
+		self.assertEqual(dn_balance, 0)
+
+		# check if cancellation of stock reco is blocked
+		self.assertRaises(NegativeStockError, sr.cancel)
+
+		repost_exists = bool(frappe.db.exists("Repost Item Valuation", {"voucher_no": sr.name}))
+		self.assertFalse(repost_exists, msg="Negative stock validation not working on reco cancellation")
+
+		# teardown
+		frappe.db.rollback()
+
+
 	def test_valid_batch(self):
 		create_batch_item_with_batch("Testing Batch Item 1", "001")
 		create_batch_item_with_batch("Testing Batch Item 2", "002")

erpnext/stock/stock_ledger.py

@@ -955,7 +955,7 @@ def get_valuation_rate(item_code, warehouse, voucher_type, voucher_no,
 
 	return valuation_rate
 
-def update_qty_in_future_sle(args, allow_negative_stock=None):
+def update_qty_in_future_sle(args, allow_negative_stock=False):
 	"""Recalculate Qty after Transaction in future SLEs based on current SLE."""
 	datetime_limit_condition = ""
 	qty_shift = args.actual_qty
@@ -1044,8 +1044,8 @@ def get_datetime_limit_condition(detail):
 			)
 		)"""
 
-def validate_negative_qty_in_future_sle(args, allow_negative_stock=None):
-	allow_negative_stock = allow_negative_stock \
+def validate_negative_qty_in_future_sle(args, allow_negative_stock=False):
+	allow_negative_stock = cint(allow_negative_stock) \
 		or cint(frappe.db.get_single_value("Stock Settings", "allow_negative_stock"))
 
 	if (args.actual_qty < 0 or args.voucher_type == "Stock Reconciliation") and not allow_negative_stock: