erts: Fix bug in setnode/2

that could lead strange things to happen when renaming a node with
a name that already exist in node and dist tables.

Problem:
erts_set_this_node() is a bit brutal and does not handle the case
when an old remote node name is reused as the new local node name.

Solution:
Treat erts_this_node and erts_this_dist_entry as all the others
with correct reference counting.

1 files changed, 38 insertions, 9 deletions

diff --git a/erts/emulator/test/distribution_SUITE_data/run.erl b/erts/emulator/test/distribution_SUITE_data/run.erl
index f5169e160c..d5ed139369 100644
--- a/erts/emulator/test/distribution_SUITE_data/run.erl
+++ b/erts/emulator/test/distribution_SUITE_data/run.erl
@@ -30,16 +30,19 @@ from(H, [_ | T]) -> from(H, T);
 from(H, []) -> [].
 
 start() ->
-    net_kernel:start([fideridum,shortnames]),
-    {ok, Node} = slave:start(host(), heppel),
-    P = spawn(Node, a, b, []),
-    B1 = term_to_binary(P),
-    N1 = node(P),
-    ok = net_kernel:stop(),
-    N2 = node(P),
-    io:format("~w~n", [N1 == N2]),
+    Result = do_it(),
+
+    %% Do GCs and node_and_dist_references
+    %% in an attempt to crash the VM (without OTP-13076 fix)
+    lists:foreach(fun(P) -> erlang:garbage_collect(P) end,
+		  processes()),
+    erts_debug:set_internal_state(available_internal_state, true),
+    erts_debug:get_internal_state(node_and_dist_references),
+
+    io:format("~w~n", [Result]),
+
     if
-	N1 == N2 -> 
+	Result ->
 	    init:stop();
 	true ->
 	    %% Make sure that the io:format/2 output is really written
@@ -47,3 +50,29 @@ start() ->
 	    erlang:yield(),
 	    init:stop()
     end.
+
+
+do_it() ->
+    {ok, _} = net_kernel:start([fideridum,shortnames]),
+    {ok, Node} = slave:start(host(), heppel),
+    P = spawn(Node, net_kernel, stop, []),
+    B1 = term_to_binary(P),
+    N1 = node(P),
+    ok = net_kernel:stop(),
+    N2 = node(P),
+
+    %% OTP-13076
+    %% Restart distribution with same node name as previous remote node
+    %% Repeat to wrap around creation
+    Result = lists:foldl(fun(_, Acc) ->
+				 timer:sleep(2),  % give net_kernel:stop() time to take effect :-(
+				 {ok, _} = net_kernel:start([heppel,shortnames]),
+				 N3 = node(P),
+				 ok = net_kernel:stop(),
+				 N4 = node(P),
+				 Acc and (N3 =:= N1) and (N4 =:= N1)
+			 end,
+			 (N2 =:= N1),
+			 lists:seq(1,3)),
+
+    Result.