Merge branch 'john/erts/fix-port-leak/OTP-13939/ERL-193' into maint-20

* john/erts/fix-port-leak/OTP-13939/ERL-193:
  Add a testcase for OTP-13939/ERL-193
  Mark socket disconnected on tcp_send_or_shutdown_error

# Conflicts:
#	lib/kernel/test/gen_tcp_misc_SUITE.erl

2 files changed, 47 insertions, 3 deletions

diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c
index 13ee935e45..fe421bfe12 100644
--- a/erts/emulator/drivers/common/inet_drv.c
+++ b/erts/emulator/drivers/common/inet_drv.c
@@ -4334,6 +4334,12 @@ static void desc_close(inet_descriptor* desc)
 	desc->event = INVALID_EVENT; /* closed by stop_select callback */
 	desc->s = INVALID_SOCKET;
 	desc->event_mask = 0;
+
+	/* mark as disconnected in case when socket is left lingering due to
+	 * {exit_on_close, false} option in gen_tcp socket creation. Next
+	 * write to socket should produce {error, enotconn} and send a
+	 * message {tcp_error,#Port<>,econnreset} */
+	desc->state &= ~INET_STATE_CONNECTED;
     }
 }
 
diff --git a/lib/kernel/test/gen_tcp_misc_SUITE.erl b/lib/kernel/test/gen_tcp_misc_SUITE.erl
index 929f66d400..331864b5de 100644
--- a/lib/kernel/test/gen_tcp_misc_SUITE.erl
+++ b/lib/kernel/test/gen_tcp_misc_SUITE.erl
@@ -50,9 +50,8 @@
 	 killing_acceptor/1,killing_multi_acceptors/1,killing_multi_acceptors2/1,
 	 several_accepts_in_one_go/1, accept_system_limit/1,
 	 active_once_closed/1, send_timeout/1, send_timeout_active/1,
-	 otp_7731/1, zombie_sockets/1, otp_7816/1, otp_8102/1,
-	 wrapping_oct/0, wrapping_oct/1,
-         otp_9389/1]).
+         otp_7731/1, zombie_sockets/1, otp_7816/1, otp_8102/1,
+         wrapping_oct/0, wrapping_oct/1, otp_9389/1, otp_13939/1]).
 
 %% Internal exports.
 -export([sender/3, not_owner/1, passive_sockets_server/2, priority_server/1, 
@@ -3014,3 +3013,42 @@ ok({ok,V}) -> V.
 get_hostname(Name) ->
     "@"++Host = lists:dropwhile(fun(C) -> C =/= $@ end, atom_to_list(Name)),
     Host.
+
+otp_13939(doc) ->
+    ["Check that writing to a remotely closed socket doesn't block forever "
+     "when exit_on_close is false."];
+otp_13939(suite) ->
+    [];
+otp_13939(Config) when is_list(Config) ->
+    {Pid, Ref} = spawn_opt(
+        fun() ->
+            {ok, Listener} = gen_tcp:listen(0, [{exit_on_close, false}]),
+            {ok, Port} = inet:port(Listener),
+
+            spawn_link(
+                fun() ->
+                    {ok, Client} = gen_tcp:connect("localhost", Port,
+                        [{active, false}]),
+                    ok = gen_tcp:close(Client)
+                end),
+
+            {ok, Accepted} = gen_tcp:accept(Listener),
+
+            ok = gen_tcp:send(Accepted, <<0:(10*1024*1024*8)>>),
+
+            %% The bug surfaces when there's a delay between the send
+            %% operations; inet:getstat is a red herring.
+            timer:sleep(100),
+
+            {error, Code} = gen_tcp:send(Accepted, <<0:(10*1024*1024*8)>>),
+            ct:pal("gen_tcp:send returned ~p~n", [Code])
+        end, [link, monitor]),
+
+    receive
+        {'DOWN', Ref, process, Pid, normal} ->
+            ok
+    after 1000 ->
+        demonitor(Ref, [flush]),
+        exit(Pid, normal),
+        ct:fail("Server process blocked on send.")
+    end.