Merge branch 'sverker/list_to_ref-fix/OTP-16438' into maint-20

* sverker/list_to_ref-fix/OTP-16438:
  erts: Fix bug in erlang:list_to_ref/1 for external refs

2 files changed, 59 insertions, 2 deletions

diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index d7a25adccb..e5854d6002 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -4420,12 +4420,16 @@ BIF_RETTYPE list_to_ref_1(BIF_ALIST_1)
 #endif
 
       etp = (ExternalThing *) HAlloc(BIF_P, hsz);
-      etp->header = make_external_ref_header(n/2);
+#if defined(ARCH_64)
+      etp->header = make_external_ref_header(n/2 + 1);
+#else
+      etp->header = make_external_ref_header(n);
+#endif
       etp->next = BIF_P->off_heap.first;
       etp->node = enp;
       i = 0;
 #if defined(ARCH_64)
-      etp->data.ui32[i] = n;
+      etp->data.ui32[i++] = n;
 #endif
       for (j = 0; j < n; j++) {
           etp->data.ui32[i] = refn[j];
diff --git a/erts/emulator/test/list_bif_SUITE.erl b/erts/emulator/test/list_bif_SUITE.erl
index f95251943d..b35ba0ff77 100644
--- a/erts/emulator/test/list_bif_SUITE.erl
+++ b/erts/emulator/test/list_bif_SUITE.erl
@@ -23,6 +23,7 @@
 
 -export([all/0, suite/0]).
 -export([hd_test/1,tl_test/1,t_length/1,t_list_to_pid/1,
+         t_list_to_ref/1, t_list_to_ext_pidportref/1,
          t_list_to_port/1,t_list_to_float/1,t_list_to_integer/1]).
 
 
@@ -33,6 +34,7 @@ suite() ->
 
 all() -> 
     [hd_test, tl_test, t_length, t_list_to_pid, t_list_to_port,
+     t_list_to_ref, t_list_to_ext_pidportref,
      t_list_to_float, t_list_to_integer].
 
 %% Tests list_to_integer and string:to_integer
@@ -126,6 +128,57 @@ t_list_to_port(Config) when is_list(Config) ->
     end,
     ok.
 
+t_list_to_ref(Config) when is_list(Config) ->
+    Ref = make_ref(),
+    RefStr = ref_to_list(Ref),
+    Ref = list_to_ref(RefStr),
+    case catch list_to_ref(id("Incorrect list")) of
+        {'EXIT', {badarg, _}} ->
+            ok;
+        Res ->
+            ct:fail("list_to_ref/1 with incorrect arg succeeded.~n"
+                    "Result: ~p", [Res])
+    end,
+    ok.
+
+%% Test list_to_pid/port/ref for external pids/ports/refs.
+t_list_to_ext_pidportref(Config) when is_list(Config) ->
+    {ok, Node} = slave:start(net_adm:localhost(), t_list_to_ext_pidportref),
+    Pid = rpc:call(Node, erlang, self, []),
+    Port = hd(rpc:call(Node, erlang, ports, [])),
+    Ref = rpc:call(Node, erlang, make_ref, []),
+
+    PidStr  = pid_to_list(Pid),
+    PortStr = port_to_list(Port),
+    RefStr  = ref_to_list(Ref),
+
+    Pid2  = list_to_pid(PidStr),
+    Port2 = list_to_port(PortStr),
+    Ref2  = list_to_ref(RefStr),
+
+    %% No, the local roundtrips of externals does not work
+    %% as 'creation' is missing in the string formats and we don't know
+    %% the 'creation' of the connected node.
+    false = (Pid =:= Pid2),
+    false = (Pid == Pid2),
+    false = (Port =:= Port2),
+    false = (Port == Port2),
+    false = (Ref =:= Ref2),
+    false = (Ref == Ref2),
+
+    %% But it works when sent back to matching node name, as 0-creations
+    %% will be converted to the local node creation.
+    true = rpc:call(Node, erlang, '=:=', [Pid, Pid2]),
+    true = rpc:call(Node, erlang, '==',  [Pid, Pid2]),
+    true = rpc:call(Node, erlang, '=:=', [Port, Port2]),
+    true = rpc:call(Node, erlang, '==',  [Port, Port2]),
+    true = rpc:call(Node, erlang, '=:=', [Ref, Ref2]),
+    true = rpc:call(Node, erlang, '==',  [Ref, Ref2]),
+
+    slave:stop(Node),
+    ok.
+
+
 %% Test list_to_float/1 with correct and incorrect arguments.
 
 t_list_to_float(Config) when is_list(Config) ->