Merge pull request #4119 from nabinhait/fix3

[fix] Return account currency only if account provided

erpnext/accounts/doctype/account/account.py

@@ -210,6 +210,8 @@ def get_parent_account(doctype, txt, searchfield, start, page_len, filters):
 
 def get_account_currency(account):
 	"""Helper function to get account currency"""
+	if not account:
+		return
 	def generator():
 		account_currency, company = frappe.db.get_value("Account", account, ["account_currency", "company"])
 		if not account_currency: