ssh: Will not hang if you attempt to send empty binary

2 files changed, 38 insertions, 11 deletions

diff --git a/lib/ssh/src/ssh_connection.erl b/lib/ssh/src/ssh_connection.erl
index c2a7c63cbe..e3b8ebfb79 100644
--- a/lib/ssh/src/ssh_connection.erl
+++ b/lib/ssh/src/ssh_connection.erl
@@ -441,7 +441,7 @@ handle_msg(#ssh_msg_channel_window_adjust{recipient_channel = ChannelId,
     
     {SendList, Channel} =  %% TODO: Datatype 0 ?
 	update_send_window(Channel0#channel{send_window_size = Size + Add},
-			   0, <<>>, Connection),
+			   0, undefined, Connection),
     
     Replies = lists:map(fun({Type, Data}) -> 
 				{connection_reply, ConnectionPid,
@@ -1073,14 +1073,15 @@ request_reply_or_data(#channel{local_id = ChannelId, user = ChannelPid},
 	false ->
 	    {{channel_data, ChannelPid, Reply}, Connection}
     end.
+update_send_window(Channel, _, undefined,
+		   #connection{channel_cache = Cache}) ->
+    do_update_send_window(Channel,  Channel#channel.send_buf, Cache);
 
-update_send_window(Channel0, DataType, Data,  
-			#connection{channel_cache = Cache}) ->
-    Buf0 = if Data == <<>> ->
-		   Channel0#channel.send_buf;
-	      true ->
-		   Channel0#channel.send_buf ++ [{DataType, Data}]
-	   end,
+update_send_window(Channel, DataType, Data,
+		   #connection{channel_cache = Cache}) ->
+    do_update_send_window(Channel, Channel#channel.send_buf ++ [{DataType, Data}], Cache).
+
+do_update_send_window(Channel0, Buf0, Cache) ->
     {Buf1, NewSz, Buf2} = get_window(Buf0, 
 				     Channel0#channel.send_packet_size,
 				     Channel0#channel.send_window_size),
diff --git a/lib/ssh/test/ssh_basic_SUITE.erl b/lib/ssh/test/ssh_basic_SUITE.erl
index 2ceaa9daa5..c224e5b800 100644
--- a/lib/ssh/test/ssh_basic_SUITE.erl
+++ b/lib/ssh/test/ssh_basic_SUITE.erl
@@ -110,12 +110,13 @@ all() ->
      {group, rsa_pass_key},
      {group, internal_error},
      daemon_already_started,
-     server_password_option, server_userpassword_option,
+     server_password_option,
+     server_userpassword_option,
      close].
 
 groups() -> 
-    [{dsa_key, [], [exec, exec_compressed, shell, known_hosts]},
-     {rsa_key, [], [exec, exec_compressed, shell, known_hosts]},     
+    [{dsa_key, [], [send, exec, exec_compressed, shell, known_hosts]},
+     {rsa_key, [], [send, exec, exec_compressed, shell, known_hosts]},
      {dsa_pass_key, [], [pass_phrase]},
      {rsa_pass_key, [], [pass_phrase]},
      {internal_error, [], [internal_error]}
@@ -532,6 +533,31 @@ internal_error(Config) when is_list(Config) ->
     ssh:stop_daemon(Pid).
 
 %%--------------------------------------------------------------------
+send(doc) ->
+    ["Test ssh_connection:send/3"];
+
+send(suite) ->
+    [];
+
+send(Config) when is_list(Config) ->
+    process_flag(trap_exit, true),
+    SystemDir = filename:join(?config(priv_dir, Config), system),
+    UserDir = ?config(priv_dir, Config),
+
+    {Pid, Host, Port} = ssh_test_lib:daemon([{system_dir, SystemDir},
+					     {user_dir, UserDir},
+					     {failfun, fun ssh_test_lib:failfun/2}]),
+    ConnectionRef =
+	ssh_test_lib:connect(Host, Port, [{silently_accept_hosts, true},
+					  {user_dir, UserDir},
+					  {user_interaction, false}]),
+    {ok, ChannelId} = ssh_connection:session_channel(ConnectionRef, infinity),
+    ok = ssh_connection:send(ConnectionRef, ChannelId, <<"Data">>),
+    ok = ssh_connection:send(ConnectionRef, ChannelId, << >>),
+    ssh:stop_daemon(Pid).
+
+
+%%--------------------------------------------------------------------
 close(doc) ->
     ["Simulate that we try to close an already closed connection"];