update custom print formats for renamed fields
diff --git a/erpnext/patches.txt b/erpnext/patches.txt
index 64cbc40..8755837 100644
--- a/erpnext/patches.txt
+++ b/erpnext/patches.txt
@@ -57,3 +57,4 @@
 execute:frappe.reset_perms("Stock Ledger Entry") #2014-06-09
 erpnext.patches.v4_0.create_custom_fields_for_india_specific_fields
 erpnext.patches.v4_0.save_default_letterhead
+erpnext.patches.v4_0.update_custom_print_formats_for_renamed_fields
diff --git a/erpnext/patches/v4_0/update_custom_print_formats_for_renamed_fields.py b/erpnext/patches/v4_0/update_custom_print_formats_for_renamed_fields.py
new file mode 100644
index 0000000..60d45cf
--- /dev/null
+++ b/erpnext/patches/v4_0/update_custom_print_formats_for_renamed_fields.py
@@ -0,0 +1,36 @@
+# Copyright (c) 2013, Web Notes Technologies Pvt. Ltd. and Contributors
+# License: GNU General Public License v3. See license.txt
+
+from __future__ import unicode_literals
+import frappe
+import re
+
+def execute():
+	# NOTE: sequence is important
+	fields_list = (
+		("amount", "base_amount"),
+		("ref_rate", "price_list_rate"),
+		("base_ref_rate", "base_price_list_rate"),
+		("adj_rate", "discount_percentage"),
+		("export_rate", "rate"),
+		("basic_rate", "base_rate"),
+		("export_amount", "amount"),
+		("reserved_warehouse", "warehouse"),
+		("import_ref_rate", "price_list_rate"),
+		("purchase_ref_rate", "base_price_list_rate"),
+		("discount_rate", "discount_percentage"),
+		("import_rate", "rate"),
+		("purchase_rate", "base_rate"),
+		("import_amount", "amount")
+	)
+
+	condition = " or ".join("""html like "%%{}%%" """.format(d[0].replace("_", "\\_")) for d in fields_list
+		if d[0] != "amount")
+
+	for name, html in frappe.db.sql("""select name, html from `tabPrint Format`
+		where standard = 'No' and ({}) and html not like '%%frappe.%%'""".format(condition)):
+			html = html.replace("wn.", "frappe.")
+			for from_field, to_field in fields_list:
+				html = re.sub(r"\b{}\b".format(from_field), to_field, html)
+
+			frappe.db.set_value("Print Format", name, "html", html)