Fix warnings on OTP 20

Author: José Valim

lib/elixir/src/elixir_errors.erl

@@ -140,6 +140,11 @@ handle_file_warning(_, _File, {_Line, v3_kernel, bad_call}) -> ok;
 %% We handle unused local warnings ourselves
 handle_file_warning(_, _File, {_Line, erl_lint, {unused_function, _}}) -> ok;
 
+%% Properly format keys using inspect.
+handle_file_warning(_, File, {Line, v3_core, {map_key_repeated, Key}}) ->
+  Message = io_lib:format("key ~ts will be overridden in map", ['Elixir.Kernel':inspect(Key)]),
+  warn(Line, File, Message);
+
 %% Make no_effect clauses pretty
 handle_file_warning(_, File, {Line, sys_core_fold, {no_effect, {erlang, F, A}}}) ->
   {Fmt, Args} = case erl_internal:comp_op(F, A) of

lib/elixir/src/elixir_map.erl

@@ -66,10 +66,11 @@ translate_map(Meta, Args, S) ->
   translate_map(Meta, Assocs, TUpdate, US).
 
 translate_struct(_Meta, Name, {'%{}', MapMeta, Assocs}, S) when is_tuple(Name) ->
-  translate_map(MapMeta, Assocs ++ [{'__struct__', Name}], nil, S);
+  translate_map(MapMeta, [{'__struct__', Name} | delete_struct_key(Assocs)], nil, S);
 
 translate_struct(Meta, Name, {'%{}', MapMeta, Args}, S) ->
-  {Assocs, TUpdate, US} = extract_assoc_update(Args, S),
+  {TAssocs, TUpdate, US} = extract_assoc_update(Args, S),
+  Assocs = delete_struct_key(TAssocs),
   Operation = operation(TUpdate, S),
 
   Struct = case Operation of
@@ -98,11 +99,11 @@ translate_struct(Meta, Name, {'%{}', MapMeta, Args}, S) ->
         {clause, Generated, [Var], [], [elixir_utils:erl_call(Ann, erlang, error, [Error])]}
       ]}, TS};
     match ->
-      translate_map(MapMeta, Assocs ++ [{'__struct__', Name}], nil, US);
+      translate_map(MapMeta, [{'__struct__', Name} | Assocs], nil, US);
     expand ->
-      Keys = [K || {K, _} <- Assocs],
+      Keys = ['__struct__'] ++ [K || {K, _} <- Assocs],
       {StructAssocs, _} = elixir_quote:escape(maps:to_list(maps:without(Keys, Struct)), false),
-      translate_map(MapMeta, StructAssocs ++ Assocs ++ [{'__struct__', Name}], nil, US)
+      translate_map(MapMeta, [{'__struct__', Name}] ++ StructAssocs ++ Assocs, nil, US)
   end.
 
 %% Helpers
@@ -190,6 +191,9 @@ extract_assoc_update([{'|', _Meta, [Update, Args]}], S) ->
   {Args, TArg, SA};
 extract_assoc_update(Args, SA) -> {Args, nil, SA}.
 
+delete_struct_key(Assocs) ->
+  lists:keydelete('__struct__', 1, Assocs).
+
 extract_key_val_op(_TUpdate, #elixir_scope{context=match}) ->
   {map_field_exact,
     fun(X, Acc) -> elixir_translator:translate(X, Acc#elixir_scope{extra=map_key}) end,

lib/elixir/test/elixir/exception_test.exs

@@ -263,25 +263,6 @@ defmodule ExceptionTest do
     assert Exception.format_exit(reason) |> String.starts_with?(expected_to_start_with)
   end
 
-  test "format_exit with call with exception" do
-    Process.flag(:trap_exit, true)
-    # Fake reason to prevent error_logger printing to stdout
-    exit_reason = {%ArgumentError{}, [{:not_a_real_module, :function, 0, []}]}
-    exit_fun = fn() -> receive do: (_ -> exit(exit_reason)) end
-    reason =
-      try do
-        :gen_fsm.sync_send_event(spawn_link(exit_fun), :hello)
-      catch
-        :exit, reason -> reason
-      end
-
-    formatted = Exception.format_exit(reason)
-    assert formatted =~ ~r"exited in: :gen_fsm\.sync_send_event\(#PID<\d+\.\d+\.\d+>, :hello\)"
-    assert formatted =~ ~r"\s{4}\*\* \(EXIT\) an exception was raised:\n"
-    assert formatted =~ ~r"\s{8}\*\* \(ArgumentError\) argument error\n"
-    assert formatted =~ ~r"\s{12}:not_a_real_module\.function/0"
-  end
-
   test "format_exit with nested calls" do
     Process.flag(:trap_exit, true)
     # Fake reason to prevent error_logger printing to stdout

lib/elixir/test/elixir/map_test.exs

@@ -87,9 +87,13 @@ defmodule MapTest do
   end
 
   test "maps with duplicate keys" do
-    assert %{a: :b, a: :c} == %{a: :c}
-    assert %{1 => 2, 1 => 3} == %{1 => 3}
-    assert %{:a => :b, a: :c} == %{a: :c}
+    ExUnit.CaptureIO.capture_io :stderr, fn ->
+      defmodule DuplicateKeys do
+        assert %{a: :b, a: :c} == %{a: :c}
+        assert %{1 => 2, 1 => 3} == %{1 => 3}
+        assert %{:a => :b, a: :c} == %{a: :c}
+      end
+    end
   end
 
   test "update maps" do