fix(selling): read overdue amount from payment ledger, not gl tags (backport #57786) (#58057)

Co-authored-by: Sudharsanan Ashok <135326972+Sudharsanan11@users.noreply.github.com>

erpnext/selling/doctype/customer/customer.py

@@ -731,8 +731,8 @@ def get_overdue_billing_threshold(customer: str, company: str) -> float:
 def get_customer_overdue_amount(customer: str, company: str) -> float:
 	"""Amount the customer owes past its due date, in company currency.
 
-	Follows the same rule as the Overdue invoice status, so a customer is only
+	Reads the Payment Ledger, the same source as `outstanding_amount`, so this agrees
-	blocked for what the invoice list already shows as overdue.
+	with the Overdue status the invoice list already shows.
 	"""
 	invoices = get_outstanding_invoices_for_customer(customer, company)
 	if not invoices:
@@ -745,27 +745,28 @@ def get_customer_overdue_amount(customer: str, company: str) -> float:
 def get_outstanding_invoices_for_customer(customer: str, company: str) -> list[frappe._dict]:
 	from frappe.query_builder.functions import Sum
 
-	gl_entry = frappe.qb.DocType("GL Entry")
+	ple = frappe.qb.DocType("Payment Ledger Entry")
 	sales_invoice = frappe.qb.DocType("Sales Invoice")
 
-	# debit - credit is always booked in company currency, so this is comparable to the overdue limit
+	# the Payment Ledger, not the GL, carries allocations made after submit (reconciled advances).
-	outstanding = Sum(gl_entry.debit) - Sum(gl_entry.credit)
+	# `amount` is booked in company currency, so this is comparable to the overdue limit.
+	outstanding = Sum(ple.amount)
 
 	return (
-		frappe.qb.from_(gl_entry)
+		frappe.qb.from_(ple)
 		.inner_join(sales_invoice)
-		.on(sales_invoice.name == gl_entry.against_voucher)
+		.on(sales_invoice.name == ple.against_voucher_no)
 		.select(
 			sales_invoice.name,
 			sales_invoice.due_date,
 			sales_invoice.base_grand_total,
 			outstanding.as_("outstanding"),
 		)
-		.where(gl_entry.party_type == "Customer")
+		.where(ple.party_type == "Customer")
-		.where(gl_entry.party == customer)
+		.where(ple.party == customer)
-		.where(gl_entry.company == company)
+		.where(ple.company == company)
-		.where(gl_entry.is_cancelled == 0)
+		.where(ple.delinked == 0)
-		.where(gl_entry.against_voucher_type == "Sales Invoice")
+		.where(ple.against_voucher_type == "Sales Invoice")
 		.groupby(sales_invoice.name, sales_invoice.due_date, sales_invoice.base_grand_total)
 		.having(outstanding > 0)
 	).run(as_dict=True)

erpnext/selling/doctype/customer/test_customer.py

@@ -422,6 +422,37 @@ class TestCustomer(ERPNextTestSuite):
 		pe.submit()
 		self.assertEqual(get_customer_overdue_amount("_Test Customer", "_Test Company"), baseline)
 
+	def test_get_customer_overdue_amount_ignores_advance_reconciled_after_submit(self):
+		from erpnext.accounts.doctype.payment_entry.test_payment_entry import create_payment_entry
+		from erpnext.accounts.doctype.sales_invoice.test_sales_invoice import create_sales_invoice
+
+		baseline = get_customer_overdue_amount("_Test Customer", "_Test Company")
+
+		# advance received before the invoice exists, so it carries no reference row
+		pe = create_payment_entry(
+			company="_Test Company",
+			party_type="Customer",
+			party="_Test Customer",
+			payment_type="Receive",
+			paid_from="Debtors - _TC",
+			paid_to="Cash - _TC",
+			paid_amount=800,
+		)
+		pe.posting_date = add_days(nowdate(), -60)
+		pe.submit()
+
+		si = create_sales_invoice(qty=1, rate=800, posting_date=add_days(nowdate(), -30))
+		self.assertEqual(get_customer_overdue_amount("_Test Customer", "_Test Company"), baseline + 800)
+
+		reconcile_payment_against_invoice(pe, si)
+
+		# reconciliation settles the invoice without re-tagging the payment's GL entries, so an
+		# overdue amount read off the GL would still count the full 800 here
+		si.reload()
+		self.assertEqual(si.outstanding_amount, 0)
+		self.assertEqual(si.status, "Paid")
+		self.assertEqual(get_customer_overdue_amount("_Test Customer", "_Test Company"), baseline)
+
 	def test_overdue_billing_threshold_on_submit(self):
 		from erpnext.accounts.doctype.sales_invoice.test_sales_invoice import create_sales_invoice
 
@@ -591,6 +622,27 @@ def set_credit_limit(customer, company, credit_limit):
 		customer.credit_limits[-1].db_insert()
 
 
+def reconcile_payment_against_invoice(payment_entry, sales_invoice):
+	"""Allocate an unlinked payment against an invoice through the reconciliation tool."""
+	pr = frappe.get_doc(
+		doctype="Payment Reconciliation",
+		company=sales_invoice.company,
+		party_type="Customer",
+		party=sales_invoice.customer,
+		receivable_payable_account=sales_invoice.debit_to,
+	)
+	pr.get_unreconciled_entries()
+	pr.allocate_entries(
+		frappe._dict(
+			{
+				"invoices": [d.as_dict() for d in pr.invoices if d.invoice_number == sales_invoice.name],
+				"payments": [d.as_dict() for d in pr.payments if d.reference_name == payment_entry.name],
+			}
+		)
+	)
+	pr.reconcile()
+
+
 def set_overdue_billing_threshold(customer, company, threshold):
 	customer = frappe.get_doc("Customer", customer)
 	for d in customer.credit_limits: