Merge branch 'bmk/inets/httpc/bad_keep_alive_mode/r14/OTP-9847' into bmk/inets/inets573_integration

Conflicts:
	lib/inets/doc/src/notes.xml
	lib/inets/src/inets_app/inets.appup.src

6 files changed, 573 insertions, 134 deletions

diff --git a/lib/inets/doc/src/notes.xml b/lib/inets/doc/src/notes.xml
index ae2557b44e..34f93586e1 100644
--- a/lib/inets/doc/src/notes.xml
+++ b/lib/inets/doc/src/notes.xml
@@ -4,7 +4,7 @@
 <chapter>
   <header>
     <copyright>
-      <year>2002</year><year>2011</year>
+      <year>2002</year><year>2012</year>
       <holder>Ericsson AB. All Rights Reserved.</holder>
     </copyright>
     <legalnotice>
@@ -62,6 +62,13 @@
           <p>Aux Id: Seq 11970 </p>
         </item>
 
+        <item>
+          <p>[httpc] Bad Keep Alive Mode. When selecting a session, 
+	  the "state" of the session (specifically if the server has 
+	  responded) was not taken into account. </p>
+          <p>Own Id: OTP-9847</p>
+        </item>
+
       </list>
     </section>
   
diff --git a/lib/inets/src/http_client/httpc_handler.erl b/lib/inets/src/http_client/httpc_handler.erl
index 587e24cc8d..4ae2275f70 100644
--- a/lib/inets/src/http_client/httpc_handler.erl
+++ b/lib/inets/src/http_client/httpc_handler.erl
@@ -295,7 +295,7 @@ handle_call(#request{address = Addr} = Request, _,
 					%% Queue + current
 					queue:len(NewPipeline) + 1,
 					client_close = ClientClose},
-		    httpc_manager:insert_session(NewSession, ProfileName),
+		    insert_session(NewSession, ProfileName),
 		    ?hcrd("session updated", []),
                     {reply, ok, State#state{pipeline = NewPipeline,
 					    session  = NewSession,
@@ -363,7 +363,7 @@ handle_call(#request{address = Addr} = Request, _,
 					%% Queue + current
 					queue:len(NewKeepAlive) + 1,
 					client_close = ClientClose},
-		    httpc_manager:insert_session(NewSession, ProfileName),
+		    insert_session(NewSession, ProfileName),
 		    ?hcrd("session updated", []),
                     {reply, ok, State#state{keep_alive = NewKeepAlive,
 					    session    = NewSession,
@@ -377,7 +377,7 @@ handle_call(#request{address = Addr} = Request, _,
 		    NewSession = 
 			Session#session{queue_length = 1,
 					client_close = ClientClose},
-		    httpc_manager:insert_session(NewSession, ProfileName),
+		    insert_session(NewSession, ProfileName),
 		    Relaxed = 
 			(Request#request.settings)#http_options.relaxed,
 		    MFA = {httpc_response, parse,
@@ -766,23 +766,52 @@ deliver_answer(Request) ->
 %% Func: code_change(_OldVsn, State, Extra) -> {ok, NewState}
 %% Purpose: Convert process state when code is changed
 %%--------------------------------------------------------------------
-%% code_change(_, #state{request = Request, pipeline = Queue} = State, 
-%% 	    [{from, '5.0.1'}, {to, '5.0.2'}]) ->
-%%     Settings = new_http_options(Request#request.settings),
-%%     NewRequest = Request#request{settings = Settings},
-%%     NewQueue = new_queue(Queue, fun new_http_options/1),
-%%     {ok, State#state{request = NewRequest, pipeline = NewQueue}};
-
-%% code_change(_, #state{request = Request, pipeline = Queue} = State, 
-%% 	    [{from, '5.0.2'}, {to, '5.0.1'}]) ->
-%%     Settings = old_http_options(Request#request.settings),
-%%     NewRequest = Request#request{settings = Settings},
-%%     NewQueue = new_queue(Queue, fun old_http_options/1),
-%%     {ok, State#state{request = NewRequest, pipeline = NewQueue}};
+
+code_change(_, 
+	    #state{session      = OldSession, 
+		   profile_name = ProfileName} = State, 
+	    upgrade_from_pre_5_7_3) ->
+    case OldSession of
+	{session, 
+	 Id, ClientClose, Scheme, Socket, SocketType, QueueLen, Type} ->
+	    NewSession = #session{id           = Id, 
+				  client_close = ClientClose, 
+				  scheme       = Scheme, 
+				  socket       = Socket, 
+				  socket_type  = SocketType,
+				  queue_length = QueueLen, 
+				  type         = Type}, 
+	    insert_session(NewSession, ProfileName), 
+	    {ok, State#state{session = NewSession}};
+	_ -> 
+	    {ok, State}
+    end;
+
+code_change(_, 
+	    #state{session      = OldSession, 
+		   profile_name = ProfileName} = State, 
+	    downgrade_to_pre_5_7_3) ->
+    case OldSession of
+	#session{id           = Id, 
+		 client_close = ClientClose, 
+		 scheme       = Scheme, 
+		 socket       = Socket, 
+		 socket_type  = SocketType,
+		 queue_length = QueueLen, 
+		 type         = Type} ->
+	    NewSession = {session, 
+			  Id, ClientClose, Scheme, Socket, SocketType, 
+			  QueueLen, Type},
+	    insert_session(NewSession, ProfileName), 
+	    {ok, State#state{session = NewSession}};
+	_ -> 
+	    {ok, State}
+    end;
 
 code_change(_, State, _) ->
     {ok, State}.
 
+
 %% new_http_options({http_options, TimeOut, AutoRedirect, SslOpts,
 %% 		  Auth, Relaxed}) ->
 %%     {http_options, "HTTP/1.1", TimeOut, AutoRedirect, SslOpts,
@@ -1181,7 +1210,7 @@ handle_pipeline(#state{status       = pipeline,
 
     case queue:out(State#state.pipeline) of
 	{empty, _} ->
-	    ?hcrd("epmty pipeline queue", []),
+	    ?hcrd("pipeline queue empty", []),
 	    
 	    %% The server may choose too teminate an idle pipeline
 	    %% in this case we want to receive the close message
@@ -1191,9 +1220,8 @@ handle_pipeline(#state{status       = pipeline,
 
 	    %% If a pipeline that has been idle for some time is not
 	    %% closed by the server, the client may want to close it.
-	    NewState   = activate_queue_timeout(TimeOut, State),
-	    NewSession = Session#session{queue_length = 0},
-	    httpc_manager:insert_session(NewSession, ProfileName),
+	    NewState = activate_queue_timeout(TimeOut, State),
+	    update_session(ProfileName, Session, #session.queue_length, 0), 
 	    %% Note mfa will be initilized when a new request 
 	    %% arrives.
 	    {noreply, 
@@ -1203,6 +1231,7 @@ handle_pipeline(#state{status       = pipeline,
 			    headers     = undefined,
 			    body        = undefined}};
 	{{value, NextRequest}, Pipeline} ->    
+	    ?hcrd("pipeline queue non-empty", []),
 	    case lists:member(NextRequest#request.id, 
 			      State#state.canceled) of		
 		true ->
@@ -1218,7 +1247,7 @@ handle_pipeline(#state{status       = pipeline,
 			Session#session{queue_length =
 					%% Queue + current
 					queue:len(Pipeline) + 1},
-		    httpc_manager:insert_session(NewSession, ProfileName),
+		    insert_session(NewSession, ProfileName),
 		    Relaxed = 
 			(NextRequest#request.settings)#http_options.relaxed,
 		    MFA = {httpc_response, 
@@ -1257,7 +1286,7 @@ handle_keep_alive_queue(
 
     case queue:out(State#state.keep_alive) of
 	{empty, _} ->
-	    ?hcrd("empty keep_alive queue", []),
+	    ?hcrd("keep_alive queue empty", []),
 	    %% The server may choose too terminate an idle keep_alive session
 	    %% in this case we want to receive the close message
 	    %% at once and not when trying to send the next
@@ -1266,8 +1295,7 @@ handle_keep_alive_queue(
 	    %% If a keep_alive session has been idle for some time is not
 	    %% closed by the server, the client may want to close it.
 	    NewState = activate_queue_timeout(TimeOut, State),
-	    NewSession = Session#session{queue_length = 0},
-	    httpc_manager:insert_session(NewSession, ProfileName),
+	    update_session(ProfileName, Session, #session.queue_length, 0),
 	    %% Note mfa will be initilized when a new request 
 	    %% arrives.
 	    {noreply, 
@@ -1279,6 +1307,7 @@ handle_keep_alive_queue(
 			   } 
 	    };
 	{{value, NextRequest}, KeepAlive} ->    
+	    ?hcrd("keep_alive queue non-empty", []),
 	    case lists:member(NextRequest#request.id, 
 			      State#state.canceled) of		
 		true ->
@@ -1388,10 +1417,10 @@ try_to_enable_pipeline_or_keep_alive(
 	    case (is_pipeline_enabled_client(Session) andalso 
 		  httpc_request:is_idempotent(Method)) of
 		true ->
-		    httpc_manager:insert_session(Session, ProfileName),
+		    insert_session(Session, ProfileName),
 		    State#state{status = pipeline};
 		false ->
-		    httpc_manager:insert_session(Session, ProfileName),
+		    insert_session(Session, ProfileName),
 		    %% Make sure type is keep_alive in session
 		    %% as it in this case might be pipeline
 		    NewSession = Session#session{type = keep_alive}, 
@@ -1403,7 +1432,9 @@ try_to_enable_pipeline_or_keep_alive(
     end.
 
 answer_request(#request{id = RequestId, from = From} = Request, Msg, 
-	       #state{timers = Timers, profile_name = ProfileName} = State) -> 
+	       #state{session      = Session, 
+		      timers       = Timers, 
+		      profile_name = ProfileName} = State) -> 
     ?hcrt("answer request", [{request, Request}, {msg, Msg}]),
     httpc_response:send(From, Msg),
     RequestTimers = Timers#timers.request_timers,
@@ -1412,12 +1443,20 @@ answer_request(#request{id = RequestId, from = From} = Request, Msg,
     Timer = {RequestId, TimerRef},
     cancel_timer(TimerRef, {timeout, Request#request.id}),
     httpc_manager:request_done(RequestId, ProfileName),
-
+    NewSession = maybe_make_session_available(ProfileName, Session), 
+    Timers2 = Timers#timers{request_timers = lists:delete(Timer, 
+							  RequestTimers)}, 
     State#state{request = Request#request{from = answer_sent},
-		timers = 
-		Timers#timers{request_timers =
-			      lists:delete(Timer, RequestTimers)}}.
-
+		session = NewSession, 
+		timers  = Timers2}.
+
+maybe_make_session_available(ProfileName, 
+			     #session{available = false} = Session) ->
+    update_session(ProfileName, Session, #session.available, true),
+    Session#session{available = true};
+maybe_make_session_available(_ProfileName, Session) ->
+    Session.
+    
 cancel_timers(#timers{request_timers = ReqTmrs, queue_timer = QTmr}) ->
     cancel_timer(QTmr, timeout_queue),
     CancelTimer = fun({_, Timer}) -> cancel_timer(Timer, timeout) end, 
@@ -1656,6 +1695,28 @@ send_raw(SocketType, Socket, ProcessBody, Acc) ->
     end.
 
 
+%% ---------------------------------------------------------------------
+%% Session wrappers
+%% ---------------------------------------------------------------------
+
+insert_session(Session, ProfileName) ->
+    httpc_manager:insert_session(Session, ProfileName).
+
+
+update_session(ProfileName, #session{id = SessionId} = Session, Pos, Value) ->
+    try
+	begin
+	    httpc_manager:update_session(ProfileName, SessionId, Pos, Value)
+	end
+    catch
+	error:undef -> % This could happen during code upgrade
+	    Session2 = erlang:setelement(Pos, Session, Value),
+	    insert_session(Session2, ProfileName)
+    end.
+
+
+%% ---------------------------------------------------------------------
+
 call(Msg, Pid) ->
     Timeout = infinity,
     call(Msg, Pid, Timeout).
diff --git a/lib/inets/src/http_client/httpc_internal.hrl b/lib/inets/src/http_client/httpc_internal.hrl
index 1d8a5b6a92..3261061d61 100644
--- a/lib/inets/src/http_client/httpc_internal.hrl
+++ b/lib/inets/src/http_client/httpc_internal.hrl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2005-2010. All Rights Reserved.
+%% Copyright Ericsson AB 2005-2012. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -112,17 +112,37 @@
 	}
        ).               
 
+
 -record(session,
 	{
-	  id,           % {{Host, Port}, HandlerPid}
-	  client_close, % true | false
-	  scheme,       % http (HTTP/TCP) | https (HTTP/SSL/TCP)
-	  socket,       % Open socket, used by connection
-	  socket_type,  % socket-type, used by connection
-	  queue_length = 1, % Current length of pipeline or keep-alive queue  
-	  type          % pipeline | keep_alive (wait for response before sending new request) 
+	  %% {{Host, Port}, HandlerPid}
+	  id, 
+
+	  %% true | false
+	  client_close, 
+
+	  %% http (HTTP/TCP) | https (HTTP/SSL/TCP)
+	  scheme, 
+
+	  %% Open socket, used by connection
+	  socket, 
+	  
+	  %% socket-type, used by connection
+	  socket_type,
+
+	  %% Current length of pipeline or keep-alive queue  
+	  queue_length = 1, 
+
+	  %% pipeline | keep_alive (wait for response before sending new request) 
+	  type, 
+
+	  %% true | false
+	  %% This will be true, when a response has been received for 
+	  %% the first request. See type above.
+	  available = false
 	 }).
 
+
 -record(http_cookie,
 	{
 	  domain,
diff --git a/lib/inets/src/http_client/httpc_manager.erl b/lib/inets/src/http_client/httpc_manager.erl
index 9015bf1ce2..3d846c2bff 100644
--- a/lib/inets/src/http_client/httpc_manager.erl
+++ b/lib/inets/src/http_client/httpc_manager.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2002-2011. All Rights Reserved.
+%% Copyright Ericsson AB 2002-2012. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -34,6 +34,7 @@
 	 retry_request/2, 
 	 redirect_request/2,
 	 insert_session/2, 
+	 update_session/4, 
 	 delete_session/2, 
 	 set_options/2, 
 	 store_cookies/3,
@@ -193,6 +194,27 @@ insert_session(Session, ProfileName) ->
 
 
 %%--------------------------------------------------------------------
+%% Function: update_session(ProfileName, SessionId, Pos, Value) -> _
+%%	Session - #session{}
+%%      ProfileName - atom()
+%%
+%% Description: Update, only one field (Pos) of the session record
+%%              identified by the SessionId, the session information 
+%%              of the httpc manager table <ProfileName>_session_db. 
+%%              Intended to be called by the httpc request handler process.
+%%--------------------------------------------------------------------
+
+update_session(ProfileName, SessionId, Pos, Value) ->
+    SessionDbName = session_db_name(ProfileName), 
+    ?hcrt("update session", 
+	  [{id,      SessionId}, 
+	   {pos,     Pos}, 
+	   {value,   Value}, 
+	   {profile, ProfileName}]),
+    ets:update_element(SessionDbName, SessionId, {Pos, Value}).
+
+
+%%--------------------------------------------------------------------
 %% Function: delete_session(SessionId, ProfileName) -> _
 %%	SessionId -  {{Host, Port}, HandlerPid}
 %%      ProfileName - atom()
@@ -548,9 +570,70 @@ terminate(_, State) ->
 %% Func: code_change(_OldVsn, State, Extra) -> {ok, NewState}
 %% Purpose: Convert process state when code is changed
 %%--------------------------------------------------------------------
-code_change(_OldVsn, State, _Extra) ->
+code_change(_, 
+	    #state{session_db = SessionDB} = State, 
+	    upgrade_from_pre_5_7_3) ->
+    Upgrade = 
+	fun({session, 
+	     Id, ClientClose, Scheme, Socket, SocketType, QueueLen, Type}) ->
+		{ok, #session{id           = Id, 
+			      client_close = ClientClose, 
+			      scheme       = Scheme, 
+			      socket       = Socket, 
+			      socket_type  = SocketType,
+			      queue_length = QueueLen, 
+			      type         = Type}};
+	   (_) -> % Already upgraded (by handler)
+		ignore
+	end,
+    (catch update_session_table(SessionDB, Upgrade)),
+    {ok, State};
+
+code_change(_, 
+	    #state{session_db = SessionDB} = State, 
+	    downgrade_to_pre_5_7_3) ->
+    Downgrade = 
+	fun(#session{id           = Id, 
+		     client_close = ClientClose, 
+		     scheme       = Scheme, 
+		     socket       = Socket, 
+		     socket_type  = SocketType,
+		     queue_length = QueueLen, 
+		     type         = Type}) ->
+		{ok, {session, 
+		      Id, ClientClose, Scheme, Socket, SocketType, 
+		      QueueLen, Type}};
+	   (_) -> % Already downgraded (by handler)
+		ignore
+	end,
+    (catch update_session_table(SessionDB, Downgrade)),
+    {ok, State};
+
+code_change(_, State, _) ->
     {ok, State}.
 
+%% This function is to catch everything that calls through the cracks...
+update_session_table(SessionDB, Transform) ->
+    ets:safe_fixtable(SessionDB, true),
+    update_session_table(SessionDB, ets:first(SessionDB), Transform),
+    ets:safe_fixtable(SessionDB, false).
+
+update_session_table(_SessionDB, '$end_of_table', _Transform) ->
+    ok;
+update_session_table(SessionDB, Key, Transform) ->
+    case ets:lookup(SessionDB, Key) of
+	[OldSession] ->
+	    case Transform(OldSession) of
+		{ok, NewSession} -> 
+		    ets:insert(SessionDB, NewSession);
+		ignore ->
+		    ok
+	    end;
+	_ ->
+	    ok
+    end,
+    update_session_table(SessionDB, ets:next(SessionDB, Key), Transform).
+
 
 %%--------------------------------------------------------------------
 %% Internal functions
@@ -679,6 +762,7 @@ select_session(Method, HostPort, Scheme, SessionType,
 			       scheme       = Scheme,
 			       queue_length = '$2',
 			       type         = SessionType,
+			       available    = true, 
 			       _            = '_'},
 	    %% {'_', {HostPort, '$1'}, false, Scheme, '_', '$2', SessionTyp}, 
 	    Candidates = ets:match(SessionDb, Pattern), 
@@ -716,7 +800,7 @@ pipeline_or_keep_alive(Request, HandlerPid, State) ->
 	    ets:insert(State#state.handler_db, {Request#request.id,
 						HandlerPid,
 						Request#request.from});
-	_  -> %timeout pipelining failed
+	_  -> % timeout pipelining failed
 	    start_handler(Request, State)
     end.
 
diff --git a/lib/inets/src/inets_app/inets.appup.src b/lib/inets/src/inets_app/inets.appup.src
index a9ffd89568..f3228b9e82 100644
--- a/lib/inets/src/inets_app/inets.appup.src
+++ b/lib/inets/src/inets_app/inets.appup.src
@@ -1,7 +1,7 @@
 %% This is an -*- erlang -*- file.
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2012. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -20,7 +20,11 @@
  [
   {"5.7.2",
    [
-    {load_module, ftp, soft_purge, soft_purge, []}
+    {load_module, ftp, soft_purge, soft_purge, []}, 
+    {update, httpc_handler, {advanced, upgrade_from_pre_4_7_3}, 
+     soft_purge, soft_purge, []}, 
+    {update, httpc_manager, {advanced, upgrade_from_pre_4_7_3}, 
+     soft_purge, soft_purge, [httpc_handler]}
    ]
   }, 
   {"5.7.1",
@@ -32,7 +36,11 @@
     {load_module, httpd_file,     soft_purge, soft_purge, []}, 
     {load_module, httpd_request,  soft_purge, soft_purge, []}, 
     {load_module, mod_responsecontrol, soft_purge, soft_purge, []},
-    {load_module, httpd_response, soft_purge, soft_purge, [mod_responsecontrol]}
+    {load_module, httpd_response, soft_purge, soft_purge, [mod_responsecontrol]},
+    {update, httpc_handler, {advanced, upgrade_from_pre_4_7_3}, 
+     soft_purge, soft_purge, []}, 
+    {update, httpc_manager, {advanced, upgrade_from_pre_4_7_3}, 
+     soft_purge, soft_purge, [httpc_handler]}
    ]
   }, 
   {"5.7", 
@@ -45,52 +53,21 @@
     {load_module, httpc_cookie,   soft_purge, soft_purge, [http_util]}, 
     {load_module, http_util,      soft_purge, soft_purge, []}, 
     {load_module, mod_responsecontrol, soft_purge, soft_purge, []},
-    {load_module, httpd_response, soft_purge, soft_purge, [mod_responsecontrol]}
+    {load_module, httpd_response, soft_purge, soft_purge, [mod_responsecontrol]},
+    {update, httpc_handler, {advanced, upgrade_from_pre_4_7_3}, 
+     soft_purge, soft_purge, []}, 
+    {update, httpc_manager, {advanced, upgrade_from_pre_4_7_3}, 
+     soft_purge, soft_purge, [httpc_handler]}
    ]
-  }, 
-  {"5.6", 
-   [
-    {load_module, ftp,               soft_purge, soft_purge, []},
-    {load_module, http_uri,          soft_purge, soft_purge, []},
-    {load_module, httpd_util,        soft_purge, soft_purge, [http_util]},
-    {load_module, httpd_file,        soft_purge, soft_purge, []}, 
-    {load_module, httpd_request,     soft_purge, soft_purge, []}, 
-    {load_module, httpc,             soft_purge, soft_purge, [httpc_manager]}, 
-    {load_module, http_transport,    soft_purge, soft_purge, [http_transport]},
-    {load_module, httpc_cookie,      soft_purge, soft_purge, [http_util]}, 
-    {load_module, http_util,         soft_purge, soft_purge, []}, 
-    {load_module, mod_responsecontrol, soft_purge, soft_purge, []},
-    {load_module, httpd_response, soft_purge, soft_purge, [mod_responsecontrol]}, 
-    {update, httpc_handler, soft,    soft_purge, soft_purge, []}, 
-    {update, httpc_manager, soft,    soft_purge, soft_purge, [httpc_handler]}, 
-    {update, ftp, soft, soft_purge,  soft_purge, []}
-   ]
-  }, 
-  {"5.5.2", 
-   [
-    {restart_application, inets}
-   ]
-  }, 
-  {"5.5.1", 
-   [
-    {restart_application, inets}
-   ]
-  }, 
-  {"5.5",
-   [
-    {restart_application, inets}
-   ]
-  }, 
-  {"5.4",
-   [
-    {restart_application, inets}
-   ]
-  } 
  ],
  [
   {"5.7.2",
    [
-    {load_module, ftp, soft_purge, soft_purge, []}
+    {load_module, ftp, soft_purge, soft_purge, []}, 
+    {update, httpc_handler, {advanced, downgrade_to_pre_4_7_3}, 
+     soft_purge, soft_purge, []}, 
+    {update, httpc_manager, {advanced, downgrade_to_pre_4_7_3}, 
+     soft_purge, soft_purge, [httpc_handler]}
    ]
   }, 
   {"5.7.1",
@@ -102,7 +79,11 @@
     {load_module, httpd_file,     soft_purge, soft_purge, []}, 
     {load_module, httpd_request,  soft_purge, soft_purge, []}, 
     {load_module, mod_responsecontrol, soft_purge, soft_purge, []},
-    {load_module, httpd_response, soft_purge, soft_purge, [mod_responsecontrol]}
+    {load_module, httpd_response, soft_purge, soft_purge, [mod_responsecontrol]},
+    {update, httpc_handler, {advanced, downgrade_to_pre_4_7_3}, 
+     soft_purge, soft_purge, []}, 
+    {update, httpc_manager, {advanced, downgrade_to_pre_4_7_3}, 
+     soft_purge, soft_purge, [httpc_handler]}
    ]
   }, 
   {"5.7", 
@@ -115,46 +96,12 @@
     {load_module, httpc_cookie,   soft_purge, soft_purge, [http_util]}, 
     {load_module, http_util,      soft_purge, soft_purge, []}, 
     {load_module, mod_responsecontrol, soft_purge, soft_purge, []},
-    {load_module, httpd_response, soft_purge, soft_purge, [mod_responsecontrol]}
-   ]
-  }, 
-  {"5.6", 
-   [
-    {load_module, ftp,              soft_purge, soft_purge, []},
-    {load_module, http_uri,         soft_purge, soft_purge, []},
-    {load_module, httpd_util,       soft_purge, soft_purge, [http_util]},
-    {load_module, httpd_file,       soft_purge, soft_purge, []}, 
-    {load_module, httpd_request,    soft_purge, soft_purge, []}, 
-    {load_module, httpc,            soft_purge, soft_purge, [httpc_manager]}, 
-    {load_module, http_transport,   soft_purge, soft_purge, [http_transport]},
-    {load_module, httpc_cookie,     soft_purge, soft_purge, [http_util]}, 
-    {load_module, http_util,        soft_purge, soft_purge, []}, 
-    {load_module, mod_responsecontrol, soft_purge, soft_purge, []},
-    {load_module, httpd_response, soft_purge, soft_purge, [mod_responsecontrol]}, 
-    {update, httpc_handler, soft,   soft_purge, soft_purge, []}, 
-    {update, httpc_manager, soft,   soft_purge, soft_purge, [httpc_handler]}, 
-    {update, ftp, soft, soft_purge, soft_purge, []}
-   ]
-  }, 
-  {"5.5.2",
-   [
-    {restart_application, inets}
-   ]
-  },
-  {"5.5.1", 
-   [
-    {restart_application, inets}
-   ]
-  }, 
-  {"5.5",
-   [
-    {restart_application, inets}
-   ]
-  },     
-  {"5.4",
-   [
-    {restart_application, inets}
+    {load_module, httpd_response, soft_purge, soft_purge, [mod_responsecontrol]},
+    {update, httpc_handler, {advanced, downgrade_to_pre_4_7_3}, 
+     soft_purge, soft_purge, []}, 
+    {update, httpc_manager, {advanced, downgrade_to_pre_4_7_3}, 
+     soft_purge, soft_purge, [httpc_handler]}
    ]
-  }     
+  }
  ]
 }.
diff --git a/lib/inets/test/httpc_SUITE.erl b/lib/inets/test/httpc_SUITE.erl
index be5d100ecc..63935a2352 100644
--- a/lib/inets/test/httpc_SUITE.erl
+++ b/lib/inets/test/httpc_SUITE.erl
@@ -90,6 +90,7 @@ all() ->
      parse_url, 
      options,
      headers_as_is, 
+     selecting_session, 
      {group, proxy}, 
      {group, ssl}, 
      {group, stream}, 
@@ -265,7 +266,7 @@ init_per_testcase(Case, Timeout, Config) ->
 
     %% inets:enable_trace(max, io, httpd),
     %% inets:enable_trace(max, io, httpc),
-    inets:enable_trace(max, io, all),
+    %% inets:enable_trace(max, io, all),
 
     NewConfig = 
 	case atom_to_list(Case) of
@@ -1807,6 +1808,7 @@ http_stream(Config) when is_list(Config) ->
 
 
 %%-------------------------------------------------------------------------
+
 http_stream_once(doc) ->
     ["Test the option stream for asynchrony requests"];
 http_stream_once(suite) ->
@@ -1814,12 +1816,12 @@ http_stream_once(suite) ->
 http_stream_once(Config) when is_list(Config) ->
     p("http_stream_once -> entry with"
       "~n   Config: ~p", [Config]),
-      
+
     p("http_stream_once -> set ipfamily to inet", []),
     ok = httpc:set_options([{ipfamily, inet}]),
     p("http_stream_once -> start dummy server", []),
     {DummyServerPid, Port} = dummy_server(ipv4),    
-    
+
     PortStr =  integer_to_list(Port),
     p("http_stream_once -> once", []),
     once(?URL_START ++ PortStr ++ "/once.html"),
@@ -1827,14 +1829,14 @@ http_stream_once(Config) when is_list(Config) ->
     once(?URL_START ++ PortStr ++ "/once_chunked.html"),
     p("http_stream_once -> dummy", []),
     once(?URL_START ++ PortStr ++ "/dummy.html"),
-    
+
     p("http_stream_once -> stop dummy server", []),
     DummyServerPid ! stop,
     p("http_stream_once -> set ipfamily to inet6fb4", []),
     ok = httpc:set_options([{ipfamily, inet6fb4}]), 
     p("http_stream_once -> done", []),
     ok.
-  
+
 once(URL) ->
     p("once -> issue sync request for ~p", [URL]),
     {ok, {{_,200,_}, [_ | _], Body}} = 
@@ -2032,6 +2034,7 @@ ipv6(SocketType, Scheme, HTTPOptions, Extra, Config) ->
 
 
 %%-------------------------------------------------------------------------
+
 headers_as_is(doc) ->
     ["Test the option headers_as_is"];
 headers_as_is(suite) ->
@@ -2049,6 +2052,321 @@ headers_as_is(Config) when is_list(Config) ->
 
 
 %%-------------------------------------------------------------------------
+
+selecting_session(doc) ->
+    ["Test selection of sessions - OTP-9847"];
+selecting_session(suite) ->
+    [];
+selecting_session(Config) when is_list(Config) ->
+    tsp("selecting_session -> entry with"
+	"~n   Config: ~p", [Config]),
+
+    tsp("selecting_session -> set ipfamily to inet"),
+    ok = httpc:set_options([{ipfamily, inet}]),
+
+    tsp("selecting_session -> start server"),
+    {ServerPid, Port} = otp_9847_server(),    
+
+    PortStr = integer_to_list(Port),
+    URL     = ?URL_START ++ PortStr ++ "/index.html",
+     
+    tsp("selecting_session -> issue the first batch (three) requests"),
+    lists:foreach(fun(P) -> 
+			  tsp("selecting_session:fun1 -> "
+			      "send stop request to ~p", [P]),
+			  P ! stop 
+		  end, 
+		  reqs(URL, ServerPid, 3, 3, false)),
+    tsp("selecting_session -> sleep some (1) to make sure nothing lingers"),
+    ?SLEEP(5000),
+    tsp("selecting_session -> "
+	"instruct the server to reply to the first request"),
+    ServerPid ! {answer, true}, 
+    receive
+	{answer, true} ->
+	    tsp("selecting_session -> "
+		"received ack from server to reply to the first request"),
+	    ok
+    end,
+    tsp("selecting_session -> issue the second batch (four) requests"),
+    lists:foreach(fun(P) -> 
+			  tsp("selecting_session:fun2 -> "
+			      "send stop request to ~p", [P]),
+			  P ! stop 
+		  end, 
+		  reqs(URL, ServerPid, 4, 1, true)),
+    tsp("selecting_session -> sleep some (2) to make sure nothing lingers"),
+    ?SLEEP(5000),
+
+    tsp("selecting_session -> stop server"),
+    ServerPid ! stop,
+    tsp("selecting_session -> set ipfamily (back) to inet6fb4"),
+    ok = httpc:set_options([{ipfamily, inet6fb4}]), 
+    tsp("selecting_session -> done"),
+    ok.
+
+reqs(URL, ServerPid, NumReqs, NumHandlers, InitialSync) ->
+    tsp("reqs -> entry with"
+	"~n   URL:         ~p"
+	"~n   ServerPid:   ~w"
+	"~n   NumReqs:     ~w"
+	"~n   NumHandlers: ~w"
+	"~n   InitialSync: ~w", 
+	[URL, ServerPid, NumReqs, NumHandlers, InitialSync]),
+    Handlers = reqs2(URL, NumReqs, [], InitialSync),
+    tsp("reqs -> "
+	"~n   Handlers: ~w", [Handlers]),
+    case length(Handlers) of
+	NumHandlers ->
+	    tsp("reqs -> "
+		"~n   NumHandlers: ~w", [NumHandlers]),
+	    ServerPid ! num_handlers, 
+	    receive
+		{num_handlers, NumHandlers} ->
+		    tsp("reqs -> received num_handlers with"
+			"~n   NumHandlers: ~w", [NumHandlers]),
+		    Handlers;
+		{num_handlers, WrongNumHandlers} ->
+		    tsp("reqs -> received num_handlers with"
+			"~n   WrongNumHandlers: ~w", [WrongNumHandlers]),
+		    exit({wrong_num_handlers1, WrongNumHandlers, NumHandlers})
+	    end;
+	WrongNumHandlers ->
+	    tsp("reqs -> "
+		"~n   WrongNumHandlers: ~w", [WrongNumHandlers]),
+	    exit({wrong_num_handlers2, WrongNumHandlers, NumHandlers})
+    end.
+	    
+
+reqs2(_URL, 0, Acc, _Sync) ->
+    lists:reverse(Acc);
+reqs2(URL, Num, Acc, Sync) ->
+    tsp("reqs2 -> entry with"
+	"~n   Num:  ~w"
+	"~n   Sync: ~w", [Num, Sync]),
+    case httpc:request(get, {URL, []}, [], [{sync, Sync}]) of
+	{ok, _Reply} ->
+	    tsp("reqs2 -> successful request: ~p", [_Reply]),
+	    receive
+		{handler, Handler, _Manager} ->
+		    %% This is when a new handler is created
+		    tsp("reqs2 -> received handler: ~p", [Handler]),
+		    case lists:member(Handler, Acc) of
+			true ->
+			    tsp("reqs2 -> duplicate handler"),
+			    exit({duplicate_handler, Handler, Num, Acc});
+			false ->
+			    tsp("reqs2 -> wait for data ack"),
+			    receive
+				{data_received, Handler} ->
+				    tsp("reqs2 -> "
+					"received data ack from ~p", [Handler]),
+				    case Sync of
+					true ->
+					    reqs2(URL, Num-1, [Handler|Acc], 
+						  false);
+					false ->
+					    reqs2(URL, Num-1, [Handler|Acc], 
+						  Sync)
+				    end
+			    end
+		    end;
+
+		{data_received, Handler} ->
+		    tsp("reqs2 -> "
+			"received data ack from ~p", [Handler]),
+		    reqs2(URL, Num-1, Acc, false)
+
+	    end;
+
+	{error, Reason} ->
+	    tsp("reqs2 -> request ~w failed: ~p", [Num, Reason]),
+	    exit({request_failed, Reason, Num, Acc})
+    end.
+
+otp_9847_server() ->
+    TC  = self(), 
+    Pid = spawn_link(fun() -> otp_9847_server_init(TC) end),
+    receive
+	{port, Port} ->
+	    {Pid, Port}
+    end.
+
+otp_9847_server_init(TC) ->
+    tsp("otp_9847_server_init -> entry with"
+	"~n   TC: ~p", [TC]),
+    {ok, ListenSocket} = 
+	gen_tcp:listen(0, [binary, inet, {packet, 0},
+			   {reuseaddr,true},
+			   {active, false}]),
+    tsp("otp_9847_server_init -> listen socket created: "
+	"~n   ListenSocket: ~p", [ListenSocket]),
+    {ok, Port} = inet:port(ListenSocket),
+    tsp("otp_9847_server_init -> Port: ~p", [Port]),
+    TC ! {port, Port},
+    otp_9847_server_main(TC, ListenSocket, false, []).
+
+otp_9847_server_main(TC, ListenSocket, Answer, Handlers) ->
+    tsp("otp_9847_server_main -> entry with"
+	"~n   TC:           ~p"
+	"~n   ListenSocket: ~p"
+	"~n   Answer:       ~p"
+	"~n   Handlers:     ~p", [TC, ListenSocket, Answer, Handlers]),
+    case gen_tcp:accept(ListenSocket, 1000) of
+	{ok, Sock} ->
+	    tsp("otp_9847_server_main -> accepted"
+		"~n   Sock: ~p", [Sock]),
+	    {Handler, Mon, Port} = otp_9847_handler(TC, Sock, Answer), 
+	    tsp("otp_9847_server_main -> handler ~p created for ~w", 
+		[Handler, Port]),
+	    gen_tcp:controlling_process(Sock, Handler),
+	    tsp("otp_9847_server_main -> control transfer"),
+	    Handler ! owner, 
+	    tsp("otp_9847_server_main -> "
+		"handler ~p informed of owner transfer", [Handler]),
+	    TC ! {handler, Handler, self()}, 
+	    tsp("otp_9847_server_main -> "
+		"TC ~p informed of handler ~p", [TC, Handler]),
+	    otp_9847_server_main(TC, ListenSocket, Answer, 
+				 [{Handler, Mon, Sock, Port}|Handlers]);
+
+	{error, timeout} ->
+	    tsp("otp_9847_server_main -> timeout"),
+	    receive 
+		{answer, true} ->
+		    tsp("otp_9847_server_main -> received answer request"),
+		    TC ! {answer, true}, 
+		    otp_9847_server_main(TC, ListenSocket, true, Handlers);
+
+		{'DOWN', _Mon, process, Pid, _Reason} ->
+		    %% Could be one of the handlers
+		    tsp("otp_9847_server_main -> received DOWN for ~p", [Pid]),
+		    otp_9847_server_main(TC, ListenSocket, Answer, 
+					 lists:keydelete(Pid, 1, Handlers));
+
+		num_handlers ->
+		    tsp("otp_9847_server_main -> "
+			"received request for number of handlers (~w)", 
+			[length(Handlers)]),
+		    TC ! {num_handlers, length(Handlers)}, 
+		    otp_9847_server_main(TC, ListenSocket, Answer, Handlers);
+
+		stop ->
+		    tsp("otp_9847_server_main -> received stop request"),
+		    %% Stop all handlers (just in case)
+		    Pids = [Handler || {Handler, _, _} <- Handlers], 
+		    lists:foreach(fun(Pid) -> Pid ! stop end, Pids),
+		    exit(normal);
+
+		Any ->
+		    tsp("otp_9847_server_main -> received"
+			"~n   Any: ~p", [Any]),
+		    exit({crap, Any})
+
+	    after 0 ->
+		    tsp("otp_9847_server_main -> nothing in queue"),
+		    otp_9847_server_main(TC, ListenSocket, Answer, Handlers)
+	    end;
+
+	Error ->
+	    exit(Error)
+    end.
+
+
+otp_9847_handler(TC, Sock, Answer) ->
+    tsp("otp_9847_handler -> entry with"
+	"~n   TC:     ~p" 
+	"~n   Sock:   ~p" 
+	"~n   Answer: ~p", [TC, Sock, Answer]),
+    Self = self(), 
+    {Pid, Mon} = 
+	spawn_opt(fun() -> 
+			  otp_9847_handler_init(TC, Self, Sock, Answer) 
+		  end, 
+		  [monitor]),
+    receive
+	{port, Port} ->
+	    tsp("otp_9847_handler -> received port message (from ~p)"
+		"~n   Port: ~p", [Pid, Port]),
+	    {Pid, Mon, Port}
+    end.
+    
+
+otp_9847_handler_init(TC, Server, Sock, Answer) ->
+    tsp("otp_9847_handler_init -> entry with"
+	"~n   TC:     ~p" 
+	"~n   Server: ~p" 
+	"~n   Sock:   ~p" 
+	"~n   Answer: ~p", [TC, Server, Sock, Answer]),
+    {ok, Port} = inet:port(Sock),
+    Server ! {port, Port},
+    receive 
+	owner ->
+	    tsp("otp_9847_handler_init -> "
+		"received owner message - activate socket"),
+	    inet:setopts(Sock, [{active, true}]),
+	    otp_9847_handler_main(TC, Server, Sock, Answer, [?HTTP_MAX_HEADER_SIZE])
+    end.
+    
+otp_9847_handler_main(TC, Server, Sock, Answer, ParseArgs) ->
+    tsp("otp_9847_handler_main -> entry with"
+	"~n   TC:        ~p" 
+	"~n   Server:    ~p" 
+	"~n   Sock:      ~p" 
+	"~n   Answer:    ~p"
+	"~n   ParseArgs: ~p", [TC, Server, Sock, Answer, ParseArgs]),
+    receive
+	stop ->
+	    tsp("otp_9847_handler_main -> received stop request"),
+	    exit(normal);
+
+	{tcp, Sock, _Data} when Answer =:= false ->
+	    tsp("otp_9847_handler_main -> received tcp data - no answer"),
+	    TC ! {data_received, self()}, 
+	    inet:setopts(Sock, [{active, true}]),
+	    %% Ignore all data
+	    otp_9847_handler_main(TC, Server, Sock, Answer, ParseArgs);
+
+	{tcp, Sock, Data} when Answer =:= true ->
+	    tsp("otp_9847_handler_main -> received tcp data - answer"),
+	    TC ! {data_received, self()}, 
+	    inet:setopts(Sock, [{active, true}]),
+	    NewParseArgs = otp_9847_handler_request(Sock, [Data|ParseArgs]), 
+	    otp_9847_handler_main(TC, Server, Sock, Answer, NewParseArgs);
+
+	{tcp_closed, Sock} ->
+	    tsp("otp_9847_handler_main -> received tcp socket closed"),
+	    exit(normal);
+
+	{tcp_error, Sock, Reason} ->
+	    tsp("otp_9847_handler_main -> socket error: ~p", [Reason]),
+	    (catch gen_tcp:close(Sock)),
+	    exit(normal)
+
+    %% after 30000 ->
+    %% 	    gen_tcp:close(Sock),
+    %% 	    exit(normal)
+    end.
+    
+otp_9847_handler_request(Sock, Args) ->
+    Msg = 
+	case httpd_request:parse(Args) of
+	    {ok, {_, "/index.html" = _RelUrl, _, _, _}} ->
+		B = 
+		    "<HTML><BODY>" ++ 
+		    "...some body part..." ++ 
+		    "</BODY></HTML>", 
+		Len = integer_to_list(length(B)), 
+		"HTTP/1.1 200 ok\r\n" ++
+		    "Content-Length:" ++ Len ++ "\r\n\r\n" ++ B
+	end,
+    gen_tcp:send(Sock, Msg),
+    [?HTTP_MAX_HEADER_SIZE].
+	    
+
+
+%%-------------------------------------------------------------------------
+
 options(doc) ->
     ["Test the option parameters."];
 options(suite) ->
@@ -2073,6 +2391,7 @@ options(Config) when is_list(Config) ->
 
 
 %%-------------------------------------------------------------------------
+
 http_invalid_http(doc) ->
     ["Test parse error"];
 http_invalid_http(suite) ->
@@ -2863,6 +3182,7 @@ otp_8739_dummy_server_main(_Parent, ListenSocket) ->
 	    exit(Error)
     end.
 
+
 %%-------------------------------------------------------------------------
 
 initial_server_connect(doc) ->