INTRODUCING ensure_utf8_string, use it to fix BLOCKER bug for Gajim/Windows (#2392)

src/common/helpers.py

@@ -534,6 +534,14 @@ def decode_string(string):
 
 	return string
 
+def ensure_utf8_string(string):
+	'''make sure string is in UTF-8'''
+	try:
+		string = decode_string(string).encode('utf-8')
+	except:
+		pass
+	return string
+
 def get_windows_reg_env(varname, default=''):
 	'''asks for paths commonly used but not exposed as ENVs
 	in english Windows 2003 those are:

src/conversation_textview.py

@@ -681,9 +681,11 @@ class ConversationTextview:
 			if day_str:
 				format += day_str + ' '
 			format += '%X' + after_str
-			# format comes as unicode, because of day_str.
-			# we convert it to the encoding that we want
-			tim_format = time.strftime(format, tim).encode('utf-8')
+			tim_format = time.strftime(format, tim)
+			# if format comes as unicode because of day_str.
+			# we convert it to the encoding that we want (and that is utf-8)
+			tim_format = helpers.ensure_utf8_string(tim_format)
+			tim_format = tim_format.encode('utf-8')
 			buffer.insert_with_tags_by_name(end_iter, tim_format + ' ',
 				*other_tags_for_time)
 		elif current_print_time == 'sometimes' and kind != 'info':