Merge pull request #39648 from frappe/mergify/bp/version-15-hotfix/pr…

…-39519

fix: don't overwrite existing terms in transaction (backport #39519)

erpnext/public/js/controllers/transaction.js

@@ -798,14 +798,14 @@ erpnext.TransactionController = class TransactionController extends erpnext.taxe
 					}
 					let selling_doctypes_for_tc = ["Sales Invoice", "Quotation", "Sales Order", "Delivery Note"];
 					if (company_doc.default_selling_terms && frappe.meta.has_field(me.frm.doc.doctype, "tc_name") &&
-					selling_doctypes_for_tc.indexOf(me.frm.doc.doctype) != -1) {
+					selling_doctypes_for_tc.includes(me.frm.doc.doctype)  && !me.frm.doc.tc_name) {
 						me.frm.set_value("tc_name", company_doc.default_selling_terms);
 					}
 					let buying_doctypes_for_tc = ["Request for Quotation", "Supplier Quotation", "Purchase Order",
 						"Material Request", "Purchase Receipt"];
 					// Purchase Invoice is excluded as per issue #3345
 					if (company_doc.default_buying_terms && frappe.meta.has_field(me.frm.doc.doctype, "tc_name") &&
-					buying_doctypes_for_tc.indexOf(me.frm.doc.doctype) != -1) {
+					buying_doctypes_for_tc.includes(me.frm.doc.doctype) && !me.frm.doc.tc_name) {
 						me.frm.set_value("tc_name", company_doc.default_buying_terms);
 					}
 				}