fix: use default supplier currency if default supplier is enabled

(cherry picked from commit 77fdc37cb7)

erpnext/selling/doctype/sales_order/sales_order.py

@@ -950,6 +950,9 @@ def get_events(start, end, filters=None):
 @frappe.whitelist()
 def make_purchase_order_for_default_supplier(source_name, selected_items=None, target_doc=None):
 	"""Creates Purchase Order for each Supplier. Returns a list of doc objects."""
+
+	from erpnext.setup.utils import get_exchange_rate
+
 	if not selected_items:
 		return
 
@@ -958,6 +961,15 @@ def make_purchase_order_for_default_supplier(source_name, selected_items=None, t
 
 	def set_missing_values(source, target):
 		target.supplier = supplier
+		target.currency = frappe.db.get_value(
+			"Supplier", filters={"name": supplier}, fieldname=["default_currency"]
+		)
+		company_currency = frappe.db.get_value(
+			"Company", filters={"name": target.company}, fieldname=["default_currency"]
+		)
+
+		target.conversion_rate = get_exchange_rate(target.currency, company_currency, args="for_buying")
+
 		target.apply_discount_on = ""
 		target.additional_discount_percentage = 0.0
 		target.discount_amount = 0.0