From effb34bbfa4144590ab4075cfcb603c50ca5c561 Mon Sep 17 00:00:00 2001
From: ruthra kumar <ruthra@erpnext.com>
Date: Tue, 25 Apr 2023 20:26:50 +0530
Subject: [PATCH] refactor: don't book exch gain/loss for sales/purchase orders

---
 .../doctype/payment_entry/payment_entry.py    | 30 +++++++++++++++----
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/erpnext/accounts/doctype/payment_entry/payment_entry.py b/erpnext/accounts/doctype/payment_entry/payment_entry.py
index ee4d4d29e2..59641e58e1 100644
--- a/erpnext/accounts/doctype/payment_entry/payment_entry.py
+++ b/erpnext/accounts/doctype/payment_entry/payment_entry.py
@@ -654,6 +654,28 @@ class PaymentEntry(AccountsController):
 				self.precision("base_received_amount"),
 			)
 
+	def calculate_base_allocated_amount_for_reference(self, d) -> float:
+		base_allocated_amount = 0
+		if d.reference_doctype in frappe.get_hooks("advance_payment_doctypes"):
+			# When referencing Sales/Purchase Order, use the source/target exchange rate depending on payment type.
+			# This is so there are no Exchange Gain/Loss generated for such doctypes
+
+			exchange_rate = 1
+			if self.payment_type == "Receive":
+				exchange_rate = self.source_exchange_rate
+			elif self.payment_type == "Pay":
+				exchange_rate = self.target_exchange_rate
+
+			base_allocated_amount += flt(
+				flt(d.allocated_amount) * flt(exchange_rate), self.precision("base_paid_amount")
+			)
+		else:
+			base_allocated_amount += flt(
+				flt(d.allocated_amount) * flt(d.exchange_rate), self.precision("base_paid_amount")
+			)
+
+		return base_allocated_amount
+
 	def set_total_allocated_amount(self):
 		if self.payment_type == "Internal Transfer":
 			return
@@ -662,9 +684,7 @@ class PaymentEntry(AccountsController):
 		for d in self.get("references"):
 			if d.allocated_amount:
 				total_allocated_amount += flt(d.allocated_amount)
-				base_total_allocated_amount += flt(
-					flt(d.allocated_amount) * flt(d.exchange_rate), self.precision("base_paid_amount")
-				)
+				base_total_allocated_amount += self.calculate_base_allocated_amount_for_reference(d)
 
 		self.total_allocated_amount = abs(total_allocated_amount)
 		self.base_total_allocated_amount = abs(base_total_allocated_amount)
@@ -881,9 +901,7 @@ class PaymentEntry(AccountsController):
 					}
 				)
 
-				allocated_amount_in_company_currency = flt(
-					flt(d.allocated_amount) * flt(d.exchange_rate), self.precision("paid_amount")
-				)
+				allocated_amount_in_company_currency = self.calculate_base_allocated_amount_for_reference(d)
 
 				gle.update(
 					{