fix: let Purchase Receipt cancel defer to Frappe's linked-document check (backport #57592) (#57602)

fix: let Purchase Receipt cancel defer to Frappe's linked-document check (#57592)

on_cancel pre-blocked cancellation with its own "Purchase Invoice is
already submitted" guard, duplicating the check Frappe already runs for any
submitted linked document. Drop the guard and the unused check_next_docstatus()
method it mirrored so the receipt defers to the framework: the Cancel All
Documents flow cancels the invoice first and then the receipt, and a direct
cancel is still rejected by Frappe's linked-document check.

Add a regression test that a direct cancel of a receipt with a submitted
invoice is rejected and rolls back, leaving no stray stock or GL entries.

(cherry picked from commit cfe18e8427)

# Conflicts:
#	erpnext/stock/doctype/purchase_receipt/purchase_receipt.py
#	erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py

Co-authored-by: Jatin3128 <140256508+Jatin3128@users.noreply.github.com>

erpnext/stock/doctype/purchase_receipt/purchase_receipt.py

@@ -404,29 +404,10 @@ class PurchaseReceipt(BuyingController):
 		self.set_consumed_qty_in_subcontract_order()
 		self.reserve_stock_for_sales_order()
 
-	def check_next_docstatus(self):
-		submit_rv = frappe.db.sql(
-			"""select t1.name
-			from `tabPurchase Invoice` t1,`tabPurchase Invoice Item` t2
-			where t1.name = t2.parent and t2.purchase_receipt = %s and t1.docstatus = 1""",
-			(self.name),
-		)
-		if submit_rv:
-			frappe.throw(_("Purchase Invoice {0} is already submitted").format(self.submit_rv[0][0]))
-
 	def on_cancel(self):
 		super().on_cancel()
 
 		self.check_on_hold_or_closed_status()
-		# Check if Purchase Invoice has been submitted against current Purchase Order
-		submitted = frappe.db.sql(
-			"""select t1.name
-			from `tabPurchase Invoice` t1,`tabPurchase Invoice Item` t2
-			where t1.name = t2.parent and t2.purchase_receipt = %s and t1.docstatus = 1""",
-			self.name,
-		)
-		if submitted:
-			frappe.throw(_("Purchase Invoice {0} is already submitted").format(submitted[0][0]))
 
 		self.update_prevdoc_status()
 		self.update_billing_status()

erpnext/stock/doctype/purchase_receipt/test_purchase_receipt.py

@@ -5446,6 +5446,32 @@ class TestPurchaseReceipt(FrappeTestCase):
 		srbnb_credit = sum(flt(row.credit) for row in gl_entries if row.account == srbnb_account)
 		self.assertAlmostEqual(srbnb_credit, pi_base_net_amount, places=2)
 
+	def test_cancel_blocked_by_submitted_invoice_rolls_back(self):
+		"""A submitted Purchase Invoice must block cancelling its Purchase Receipt. Frappe's backlink
+		check rejects the cancel only after on_cancel has run stock, GL, and status work, so the whole
+		transaction has to roll back: the receipt stays submitted with no leaked ledger entries."""
+		pr = make_purchase_receipt()
+		pi = make_purchase_invoice(pr.name)
+		pi.insert()
+		pi.submit()
+
+		pr.reload()
+		status_before = pr.status
+		sle_before = frappe.db.count("Stock Ledger Entry", {"voucher_no": pr.name})
+		gle_before = frappe.db.count("GL Entry", {"voucher_no": pr.name})
+
+		frappe.db.savepoint("before_blocked_cancel")
+		with self.assertRaises(frappe.LinkExistsError) as cm:
+			pr.cancel()
+		self.assertIn(pi.name, str(cm.exception))
+		frappe.db.rollback(save_point="before_blocked_cancel")  # mimic the request-level rollback
+
+		pr.reload()
+		self.assertEqual(pr.docstatus, 1)
+		self.assertEqual(pr.status, status_before)
+		self.assertEqual(frappe.db.count("Stock Ledger Entry", {"voucher_no": pr.name}), sle_before)
+		self.assertEqual(frappe.db.count("GL Entry", {"voucher_no": pr.name}), gle_before)
+
 
 def prepare_data_for_internal_transfer():
 	from erpnext.accounts.doctype.sales_invoice.test_sales_invoice import create_internal_supplier