Fix error_logger backend 'Format error' on unicode in Args

src/error_logger_lager_h.erl

@@ -197,7 +197,7 @@ log_event(Event, State) ->
                     ?LOGFMT(error, Pid, "Webmachine error at path ~p : ~s", [Path, format_reason(StackTrace)]);
                 _ ->
                     ?CRASH_LOG(Event),
-                    ?LOGMSG(error, Pid, lager:safe_format(Fmt, Args, ?DEFAULT_TRUNCATION))
+                    ?LOGFMT(error, Pid, Fmt, Args)
             end;
         {error_report, _GL, {Pid, std_error, D}} ->
             ?CRASH_LOG(Event),
@@ -217,11 +217,11 @@ log_event(Event, State) ->
             ?CRASH_LOG(Event),
             ?LOGMSG(error, Pid, "CRASH REPORT " ++ format_crash_report(Self, Neighbours));
         {warning_msg, _GL, {Pid, Fmt, Args}} ->
-            ?LOGMSG(warning, Pid, lager:safe_format(Fmt, Args, ?DEFAULT_TRUNCATION));
+            ?LOGFMT(warning, Pid, Fmt, Args);
         {warning_report, _GL, {Pid, std_warning, Report}} ->
             ?LOGMSG(warning, Pid, print_silly_list(Report));
         {info_msg, _GL, {Pid, Fmt, Args}} ->
-            ?LOGMSG(info, Pid, lager:safe_format(Fmt, Args, ?DEFAULT_TRUNCATION));
+            ?LOGFMT(info, Pid, Fmt, Args);
         {info_report, _GL, {Pid, std_info, D}} when is_list(D) ->
             Details = lists:sort(D),
             case Details of

test/lager_test_backend.erl

@@ -709,6 +709,17 @@ error_logger_redirect_test_() ->
                         ?assertEqual(Expected, lists:flatten(Msg))
                 end
             },
+            {"error messages with unicode characters in Args are printed",
+                fun() ->
+                        sync_error_logger:error_msg("~ts", ["Привет!"]),
+                        _ = gen_event:which_handlers(error_logger),
+                        {Level, _, Msg,Metadata} = pop(),
+                        ?assertEqual(lager_util:level_to_num(error),Level),
+                        ?assertEqual(self(),proplists:get_value(pid,Metadata)),
+                        ?assertEqual("Привет!", lists:flatten(Msg))
+                end
+            },
+
             {"error messages are truncated at 4096 characters",
                 fun() ->
                         sync_error_logger:error_msg("doom, doom has come upon you all ~p", [string:copies("doom", 10000)]),
@@ -808,6 +819,27 @@ error_logger_redirect_test_() ->
                         ?assert(length(lists:flatten(Msg)) < 5100)
                 end
             },
+            {"info messages with unicode characters in Args are printed",
+                fun() ->
+                        sync_error_logger:info_msg("~ts", ["Привет!"]),
+                        _ = gen_event:which_handlers(error_logger),
+                        {Level, _, Msg,Metadata} = pop(),
+                        ?assertEqual(lager_util:level_to_num(info),Level),
+                        ?assertEqual(self(),proplists:get_value(pid,Metadata)),
+                        ?assertEqual("Привет!", lists:flatten(Msg))
+                end
+            },
+            {"warning messages with unicode characters in Args are printed",
+                fun() ->
+                        sync_error_logger:warning_msg("~ts", ["Привет!"]),
+                        Map = error_logger:warning_map(),
+                        _ = gen_event:which_handlers(error_logger),
+                        {Level, _, Msg,Metadata} = pop(),
+                        ?assertEqual(lager_util:level_to_num(Map),Level),
+                        ?assertEqual(self(),proplists:get_value(pid,Metadata)),
+                        ?assertEqual("Привет!", lists:flatten(Msg))
+                end
+            },
 
             {"warning messages are printed at the correct level",
                 fun() ->