fix: IntegrityError while cancelling journals against cr note
diff --git a/erpnext/accounts/utils.py b/erpnext/accounts/utils.py
index a03de9e..2608c03 100644
--- a/erpnext/accounts/utils.py
+++ b/erpnext/accounts/utils.py
@@ -1512,9 +1512,12 @@
 		ref_doc = frappe.get_doc(voucher_type, voucher_no)
 
 		# Didn't use db_set for optimisation purpose
-		ref_doc.outstanding_amount = outstanding["outstanding_in_account_currency"]
+		ref_doc.outstanding_amount = outstanding["outstanding_in_account_currency"] or 0.0
 		frappe.db.set_value(
-			voucher_type, voucher_no, "outstanding_amount", outstanding["outstanding_in_account_currency"]
+			voucher_type,
+			voucher_no,
+			"outstanding_amount",
+			outstanding["outstanding_in_account_currency"] or 0.0,
 		)
 
 		ref_doc.set_status(update=True)