fix: set currency on change of company considering customer default c…

…urrency (backport #42405) (#42547)

fix: set currency on change of company considering customer default currency (#42405)

(cherry picked from commit 4986f28)

# Conflicts:
#	erpnext/public/js/controllers/transaction.js

Co-authored-by: Nabin Hait <nabinhait@gmail.com>

erpnext/public/js/controllers/transaction.js

@@ -826,6 +826,7 @@ erpnext.TransactionController = class TransactionController extends erpnext.taxe
 		var me = this;
 		var set_pricing = function() {
 			if(me.frm.doc.company && me.frm.fields_dict.currency) {
+<<<<<<< HEAD
 				var company_currency = me.get_company_currency();
 				var company_doc = frappe.get_doc(":Company", me.frm.doc.company);
 
@@ -858,15 +859,78 @@ erpnext.TransactionController = class TransactionController extends erpnext.taxe
 						me.frm.set_value("tc_name", company_doc.default_buying_terms);
 					}
 				}
+=======
+>>>>>>> 4986f28a89 (fix: set currency on change of company considering customer default currency (#42405))
 				frappe.run_serially([
-					() => me.frm.script_manager.trigger("currency"),
+					() => get_party_currency(),
 					() => me.update_item_tax_map(),
 					() => me.apply_default_taxes(),
-					() => me.apply_pricing_rule()
+					() => me.apply_pricing_rule(),
+					() => set_terms(),
+					() => set_letter_head(),
 				]);
 			}
 		}
 
+		var get_party_currency = function() {
+			var party_type = frappe.meta.has_field(me.frm.doc.doctype, "customer") ? "Customer" : "Supplier";
+			var party_name = me.frm.doc[party_type.toLowerCase()];
+			if (party_name) {
+				frappe.call({
+					method: "frappe.client.get_value",
+					args: {
+						doctype: party_type,
+						filters: { name: party_name },
+						fieldname: "default_currency",
+					},
+					callback: function (r) {
+						if (r.message) {
+							set_currency(r.message.default_currency);
+						}
+					}
+				})
+			} else {
+				set_currency();
+			}
+		}
+
+		var set_currency = function(party_default_currency) {
+			var company_currency = me.get_company_currency();
+			var currency = party_default_currency || company_currency;
+			if (me.frm.doc.currency != currency) {
+				me.frm.set_value("currency", currency);
+			}
+
+			if (me.frm.doc.currency == company_currency) {
+				me.frm.set_value("conversion_rate", 1.0);
+			}
+			if (me.frm.doc.price_list_currency == company_currency) {
+				me.frm.set_value('plc_conversion_rate', 1.0);
+			}
+
+			me.frm.script_manager.trigger("currency");
+		}
+
+		var set_terms = function() {
+			if (frappe.meta.has_field(me.frm.doc.doctype, "tc_name") && !me.frm.doc.tc_name) {
+				var company_doc = frappe.get_doc(":Company", me.frm.doc.company);
+				var selling_doctypes = ["Quotation", "Sales Order", "Delivery Note", "Sales Invoice"];
+				var company_terms_fieldname = selling_doctypes.includes(me.frm.doc.doctype) ? "default_selling_terms" : "default_buying_terms";
+				if (company_doc && company_doc[company_terms_fieldname]) {
+					me.frm.set_value("tc_name", company_doc[company_terms_fieldname]);
+				}
+			}
+		}
+
+		var set_letter_head = function() {
+			if(me.frm.fields_dict.letter_head) {
+				var company_doc = frappe.get_doc(":Company", me.frm.doc.company);
+				if (company_doc && company_doc.default_letter_head) {
+					me.frm.set_value("letter_head", company_doc.default_letter_head);
+				}
+			}
+		}
+
 		var set_party_account = function(set_pricing) {
 			if (["Sales Invoice", "Purchase Invoice"].includes(me.frm.doc.doctype)) {
 				if(me.frm.doc.doctype=="Sales Invoice") {