Merge pull request #4228 from nabinhait/exchange_rate

[fix] account currency is not mandatory in get exchange rate
diff --git a/erpnext/accounts/doctype/journal_entry/journal_entry.py b/erpnext/accounts/doctype/journal_entry/journal_entry.py
index 9eaf1dd..0826521 100644
--- a/erpnext/accounts/doctype/journal_entry/journal_entry.py
+++ b/erpnext/accounts/doctype/journal_entry/journal_entry.py
@@ -817,11 +817,19 @@
 	return grid_values
 
 @frappe.whitelist()
-def get_exchange_rate(account, account_currency, company,
+def get_exchange_rate(account, account_currency=None, company=None,
 		reference_type=None, reference_name=None, debit=None, credit=None, exchange_rate=None):
 	from erpnext.setup.utils import get_exchange_rate
+	account_details = frappe.db.get_value("Account", account, 
+		["account_type", "root_type", "account_currency", "company"], as_dict=1)
+	
+	if not company:
+		company = account_details.company
+		
+	if not account_currency:
+		account_currency = account_details.account_currency
+		
 	company_currency = get_company_currency(company)
-	account_details = frappe.db.get_value("Account", account, ["account_type", "root_type"], as_dict=1)
 
 	if account_currency != company_currency:
 		if reference_type in ("Sales Invoice", "Purchase Invoice") and reference_name: