feat: recursive product discount
diff --git a/erpnext/public/js/controllers/transaction.js b/erpnext/public/js/controllers/transaction.js
index 7d90d26..6f57793 100644
--- a/erpnext/public/js/controllers/transaction.js
+++ b/erpnext/public/js/controllers/transaction.js
@@ -576,7 +576,7 @@
 									var d = locals[cdt][cdn];
 									me.add_taxes_from_item_tax_template(d.item_tax_rate);
 									if (d.free_item_data) {
-										me.apply_product_discount(d.free_item_data);
+										me.apply_product_discount(d);
 									}
 								},
 								() => {
@@ -1163,7 +1163,7 @@
 
 	calculate_stock_uom_rate: function(doc, cdt, cdn) {
 		let item = frappe.get_doc(cdt, cdn);
-		item.stock_uom_rate = flt(item.rate)/flt(item.conversion_factor);	
+		item.stock_uom_rate = flt(item.rate)/flt(item.conversion_factor);
 		refresh_field("stock_uom_rate", item.name, item.parentfield);
 	},
 	service_stop_date: function(frm, cdt, cdn) {
@@ -1504,7 +1504,7 @@
 			}
 
 			if (d.free_item_data) {
-				me.apply_product_discount(d.free_item_data);
+				me.apply_product_discount(d);
 			}
 
 			if (d.apply_rule_on_other_items) {
@@ -1538,20 +1538,30 @@
 		}
 	},
 
-	apply_product_discount: function(free_item_data) {
-		const items = this.frm.doc.items.filter(d => (d.item_code == free_item_data.item_code
-			&& d.is_free_item)) || [];
+	apply_product_discount: function(args) {
+		const items = this.frm.doc.items.filter(d => (d.is_free_item)) || [];
 
-		if (!items.length) {
-			let row_to_modify = frappe.model.add_child(this.frm.doc,
-				this.frm.doc.doctype + ' Item', 'items');
+		const exist_items = items.map(row => row.item_code);
 
-			for (let key in free_item_data) {
-				row_to_modify[key] = free_item_data[key];
+		args.free_item_data.forEach(pr_row => {
+			let row_to_modify = {};
+			if (!items || !in_list(exist_items, pr_row.item_code)) {
+
+				row_to_modify = frappe.model.add_child(this.frm.doc,
+					this.frm.doc.doctype + ' Item', 'items');
+
+			} else if(items) {
+				row_to_modify = items.filter(d => d.item_code === pr_row.item_code)[0];
 			}
-		} if (items && items.length && free_item_data) {
-			items[0].qty = free_item_data.qty
-		}
+
+			for (let key in pr_row) {
+				row_to_modify[key] = pr_row[key];
+			}
+		});
+
+		// free_item_data is a temporary variable
+		args.free_item_data = '';
+		refresh_field('items');
 	},
 
 	apply_price_list: function(item, reset_plc_conversion) {