From fb1f6b146c93211fed8d255fd967f69084922645 Mon Sep 17 00:00:00 2001
From: Dan Gudmundsson <dgud@erlang.org>
Date: Mon, 17 Mar 2025 10:59:35 +0100
Subject: [PATCH] Fix crash in initial_call
If user set the initial_call to undefined or something else,
the shells process list function 'i()' crashed.
---
lib/stdlib/src/proc_lib.erl | 2 ++
lib/stdlib/test/proc_lib_SUITE.erl | 14 ++++++++++++++
2 files changed, 16 insertions(+)
diff --git a/lib/stdlib/src/proc_lib.erl b/lib/stdlib/src/proc_lib.erl
index 80909fb2c293..7633b2b50ec9 100644
--- a/lib/stdlib/src/proc_lib.erl
+++ b/lib/stdlib/src/proc_lib.erl
@@ -902,6 +902,8 @@ raw_initial_call(ProcInfo) when is_list(ProcInfo) ->
case lists:keyfind({dictionary, '$initial_call'}, 1, ProcInfo) of
{{dictionary,_}, {_,_,_}=MFA} ->
MFA;
+ {{dictionary,_}, _} ->
+ false;
false ->
case lists:keyfind(dictionary, 1, ProcInfo) of
{dictionary,Dict} ->
diff --git a/lib/stdlib/test/proc_lib_SUITE.erl b/lib/stdlib/test/proc_lib_SUITE.erl
index 6683fd7d2a14..4b9f59b76ed2 100644
--- a/lib/stdlib/test/proc_lib_SUITE.erl
+++ b/lib/stdlib/test/proc_lib_SUITE.erl
@@ -383,6 +383,20 @@ spawn_opt(Config) when is_list(Config) ->
FunMFArgs = proc_lib:initial_call(Pid1),
FunMFArity = proc_lib:translate_initial_call(Pid1),
Pid1 ! die,
+
+ %% Check modified initial_call
+
+ Pid2 = proc_lib:spawn_opt(fun() ->
+ put('$initial_call', undefined),
+ receive _ -> ok end
+ end, [link]),
+ false = proc_lib:initial_call(Pid2),
+ {proc_lib, init_p, 5} = proc_lib:translate_initial_call(Pid2),
+ Dict2 = process_info(Pid2, [{dictionary, '$initial_call'}]),
+ false = proc_lib:initial_call(Dict2),
+ {proc_lib, init_p, 5} = proc_lib:translate_initial_call(Dict2),
+
+ Pid2 ! die,
ok.