Translate the msg in _ function according to the passed lang, support multiple language in frappe.cash()

frappe/__init__.py

@@ -48,7 +48,8 @@ def _(msg, lang=None):
 	# msg should always be unicode
 	msg = as_unicode(msg).strip()
 
-	return get_full_dict(local.lang).get(msg) or msg
+	# Retrun lang_full_dict according to lang passed parameter
+	return get_full_dict(lang).get(msg) or msg
 
 def as_unicode(text, encoding='utf-8'):
 	'''Convert to unicode if required'''

frappe/translate.py

@@ -179,7 +179,9 @@ def get_full_dict(lang):
 		return {}
 
 	# found in local, return!
-	if getattr(frappe.local, 'lang_full_dict', None) is not None:
+	# Check if the passed lang exists in lang_full_dict cash in frappe
+	if not getattr(frappe.local, 'lang_full_dict',
+				   None) is None and frappe.local.lang_full_dict and lang in frappe.local.lang_full_dict:
 		return frappe.local.lang_full_dict
 
 	frappe.local.lang_full_dict = load_lang(lang)