File 0329-fix-supervisor-fix-return-value-when-process-is-alre.patch of Package erlang
From 1e04e7add376119bab0299f895970ded8d90ad3f Mon Sep 17 00:00:00 2001
From: Thales Macedo Garitezi <thalesmg@gmail.com>
Date: Tue, 28 Mar 2023 14:36:53 -0300
Subject: [PATCH 1/2] fix(supervisor): fix return value when process is already
registered
This fixes a bug where the return type for `supervisor:start_child/2`
was not being respected.
If a supervisor tries to start a child who tries to register the same
local name that a running process has already registered, the return
value was of the form `{error, {{already_started, pid()}, child_spec()}}`
rather than `{error, {already_started, pid()}}`.
---
lib/stdlib/src/supervisor.erl | 2 ++
lib/stdlib/test/supervisor_SUITE.erl | 32 +++++++++++++++++++++++++---
2 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/lib/stdlib/src/supervisor.erl b/lib/stdlib/src/supervisor.erl
index de44ce55ee..6636fbc46d 100644
--- a/lib/stdlib/src/supervisor.erl
+++ b/lib/stdlib/src/supervisor.erl
@@ -716,6 +716,8 @@ handle_start_child(Child, State) ->
{{ok, Pid}, save_child(Child#child{pid = Pid}, State)};
{ok, Pid, Extra} ->
{{ok, Pid, Extra}, save_child(Child#child{pid = Pid}, State)};
+ {error, {already_started, _Pid} = What} ->
+ {{error, What}, State};
{error, What} ->
{{error, {What, Child}}, State}
end;
diff --git a/lib/stdlib/test/supervisor_SUITE.erl b/lib/stdlib/test/supervisor_SUITE.erl
index a9cf48e997..9532aaf118 100644
--- a/lib/stdlib/test/supervisor_SUITE.erl
+++ b/lib/stdlib/test/supervisor_SUITE.erl
@@ -30,7 +30,7 @@
%% Internal export
-export([init/1, terminate_all_children/1,
- middle9212/0, gen_server9212/0, handle_info/2]).
+ middle9212/0, gen_server9212/0, handle_info/2, start_registered_name/1]).
%% API tests
-export([ sup_start_normal/1, sup_start_ignore_init/1,
@@ -90,7 +90,7 @@
hanging_restart_loop_simple/1, code_change/1, code_change_map/1,
code_change_simple/1, code_change_simple_map/1,
order_of_children/1, scale_start_stop_many_children/1,
- format_log_1/1, format_log_2/1]).
+ format_log_1/1, format_log_2/1, already_started_outside_supervisor/1]).
%%-------------------------------------------------------------------------
@@ -119,7 +119,7 @@ all() ->
hanging_restart_loop_rest_for_one, hanging_restart_loop_simple,
code_change, code_change_map, code_change_simple, code_change_simple_map,
order_of_children, scale_start_stop_many_children,
- format_log_1, format_log_2].
+ format_log_1, format_log_2, already_started_outside_supervisor].
groups() ->
[{sup_start, [],
@@ -3677,6 +3677,29 @@ significant_upgrade_child(_Config) ->
ok.
+%% Test trying to start a child that uses an already registered name.
+already_started_outside_supervisor(_Config) ->
+ process_flag(trap_exit, true),
+ {ok, SupPid} = start_link({ok, {#{}, []}}),
+ RegName = registered_name,
+ Child = #{id => child,
+ start => {?MODULE, start_registered_name, [RegName]},
+ restart => transient,
+ significant => false},
+ %% We start another process and register the name.
+ Pid = spawn_link(fun() ->
+ true = register(RegName, self()),
+ receive
+ die -> ok
+ end
+ end),
+ {error, {already_started, P}} = supervisor:start_child(SupPid, Child),
+ Pid = P,
+ terminate(SupPid, shutdown),
+ Pid ! die,
+ ok = check_exit([SupPid]),
+ ok.
+
%%-------------------------------------------------------------------------
terminate(Pid, Reason) when Reason =/= supervisor ->
terminate(dummy, Pid, dummy, Reason).
@@ -3769,3 +3792,6 @@ check_no_exit(Timeout) ->
{'EXIT', Pid, Else} ->
ct:fail({bad_exit_reason, Else})
end.
+
+start_registered_name(Name) ->
+ supervisor:start_link({local, Name}, ?MODULE, []).
--
2.35.3
