Merge branch 'siri/sasl/upgrade-erts/OTP-9438'

* siri/sasl/upgrade-erts/OTP-9438:
  Fix bug in erts upgrade on windows
  Add release vsn info to erts_vsn_changed warning
  Check for sasl application in systools:make_script and make_relup
  Add syntax check of relup to check_install_release and install_release
  Add documentation for upgrade from pre R15 to post R15 sasl
  Handle upgrade from pre R15 to post R15 sasl
  Step version of sasl to 2.2 for R15
  Document upgrade instructions restart_new_emulator and restart_emulator
  Wait for two restarts in upgrade_restart test
  Add restart_new_emulator instruction to kernel, stdlib and sasl appups
  Distinguish restart_new_emulator from restart_emulator in upgrade instructions
  Upgrade erts: merge sys.config for tmp release instead of using old
  Allow regexp for version in .appup
  Restart emulator before running upgrade script when erts is upgraded

Conflicts:
	lib/sasl/src/release_handler.erl
	lib/sasl/test/release_handler_SUITE.erl

6 files changed, 719 insertions, 184 deletions

diff --git a/lib/sasl/src/release_handler.erl b/lib/sasl/src/release_handler.erl
index 5650f1433d..4e8cb4628c 100644
--- a/lib/sasl/src/release_handler.erl
+++ b/lib/sasl/src/release_handler.erl
@@ -26,9 +26,9 @@
 	 create_RELEASES/1, create_RELEASES/2, create_RELEASES/4,
 	 unpack_release/1,
 	 check_install_release/1, check_install_release/2,
-	 install_release/1, install_release/2, remove_release/1,
-	 which_releases/0, which_releases/1, make_permanent/1,
-	 reboot_old_release/1,
+	 install_release/1, install_release/2, new_emulator_upgrade/2,
+	 remove_release/1, which_releases/0, which_releases/1,
+	 make_permanent/1, reboot_old_release/1,
 	 set_unpacked/2, set_removed/1, install_file/2]).
 -export([upgrade_app/2, downgrade_app/2, downgrade_app/3,
 	 upgrade_script/2, downgrade_script/3,
@@ -41,7 +41,7 @@
 %% Internal exports, a client release_handler may call this functions.
 -export([do_write_release/3, do_copy_file/2, do_copy_files/2,
 	 do_copy_files/1, do_rename_files/1, do_remove_files/1,
-	 do_write_file/2, do_ensure_RELEASES/1]).
+	 remove_file/1, do_write_file/2, do_ensure_RELEASES/1]).
 
 -record(state, {unpurged = [],
 		root,
@@ -62,10 +62,11 @@
 %%             remove                -
 %% current     make_permanent        permanent
 %%             install other         old
+%%             restart node          unpacked
 %%             remove                -
 %% permanent   make other permanent  old
 %%             install               permanent
-%% old         reboot                permanen
+%% old         reboot_old            permanent
 %%             install               current
 %%             remove                -
 %%-----------------------------------------------------------------
@@ -75,6 +76,14 @@
 -define(timeout, 10000).
 
 %%-----------------------------------------------------------------
+%% The version set on the temporary release that will be used when the
+%% emulator is upgraded.
+-define(tmp_vsn(__BaseVsn__), "__new_emulator__"++__BaseVsn__).
+
+
+
+
+%%-----------------------------------------------------------------
 %% Assumes the following file structure:
 %% root --- lib --- Appl-Vsn1 --- <src>
 %%       |       |             |- ebin
@@ -184,11 +193,15 @@ check_check_install_options([],Purge) ->
 %%-----------------------------------------------------------------
 %% Purpose: Executes the relup script for the specified version.
 %%          The release must be unpacked.
-%% Returns: {ok, FromVsn, Descr} | {error, Reason}
+%% Returns: {ok, FromVsn, Descr} |
+%%          {continue_after_restart, FromVsn, Descr} |
+%%          {error, Reason}
 %%          Reason = {already_installed, Vsn} |
 %%                   {bad_relup_file, RelFile} |
 %%                   {no_such_release, Vsn} |
 %%                   {no_such_from_vsn, Vsn} |
+%%                   {could_not_create_hybrid_boot,Why} |
+%%                   {missing_base_app,Vsn,App} |
 %%                   {illegal_option, Opt}} |
 %%                   exit_reason()
 %%-----------------------------------------------------------------
@@ -231,6 +244,21 @@ check_timeout(Int) when is_integer(Int), Int > 0 -> true;
 check_timeout(_Else) -> false.
 
 %%-----------------------------------------------------------------
+%% Purpose: Called by boot script after emulator is restarted due to
+%%          new erts version.
+%% Returns: Same as install_release/2
+%%          If this crashes, the emulator restart will fail
+%%          (since the function is called from the boot script)
+%%          and there will be a rollback.
+%%-----------------------------------------------------------------
+new_emulator_upgrade(Vsn, Opts) ->
+    Result = call({install_release, Vsn, reboot, Opts}),
+    error_logger:info_msg(
+      "~p:install_release(~p,~p) completed after node restart "
+      "with new emulator version~nResult: ~p~n",[?MODULE,Vsn,Opts,Result]),
+    Result.
+
+%%-----------------------------------------------------------------
 %% Purpose: Makes the specified release version be the one that is
 %%          used when the system starts (or restarts).
 %%          The release must be installed (not unpacked).
@@ -322,7 +350,7 @@ check_script(Script, LibDirs) ->
 %%-----------------------------------------------------------------
 %% eval_script(Script, Apps, LibDirs, NewLibs, Opts) ->
 %%                                             {ok, UnPurged} |
-%%                                             restart_new_emulator |
+%%                                             restart_emulator |
 %%                                             {error, Error}
 %%                                             {'EXIT', Reason}
 %% If sync_nodes is present, the calling process must have called
@@ -359,7 +387,7 @@ create_RELEASES(Root, RelDir, RelFile, LibDirs) ->
 
 %%-----------------------------------------------------------------
 %% Func: upgrade_app(App, Dir) -> {ok, Unpurged}
-%%                              | restart_new_emulator
+%%                              | restart_emulator
 %%                              | {error, Error}
 %% Types:
 %%   App = atom()
@@ -379,7 +407,7 @@ upgrade_app(App, NewDir) ->
 %%-----------------------------------------------------------------
 %% Func: downgrade_app(App, Dir)
 %%       downgrade_app(App, Vsn, Dir) -> {ok, Unpurged}
-%%                                     | restart_new_emulator
+%%                                     | restart_emulator
 %%                                     | {error, Error}
 %% Types:
 %%   App = atom()
@@ -587,7 +615,7 @@ handle_call({check_install_release, Vsn, Purge}, _From, S) ->
 handle_call({install_release, Vsn, ErrorAction, Opts}, From, S) ->
     NS = resend_sync_nodes(S),
     case catch do_install_release(S, Vsn, Opts) of
-	{ok, NewReleases, CurrentVsn, Descr} -> 
+	{ok, NewReleases, [], CurrentVsn, Descr} ->
 	    {reply, {ok, CurrentVsn, Descr}, NS#state{releases=NewReleases}};
 	{ok, NewReleases, Unpurged, CurrentVsn, Descr} ->
 	    Timer =
@@ -602,10 +630,14 @@ handle_call({install_release, Vsn, ErrorAction, Opts}, From, S) ->
 	    {reply, {ok, CurrentVsn, Descr}, NewS};
 	{error, Reason}   ->
 	    {reply, {error, Reason}, NS}; 
-	{restart_new_emulator, CurrentVsn, Descr} ->
+	{restart_emulator, CurrentVsn, Descr} ->
 	    gen_server:reply(From, {ok, CurrentVsn, Descr}),
 	    init:reboot(),
 	    {noreply, NS};
+	{restart_new_emulator, CurrentVsn, Descr} ->
+	    gen_server:reply(From, {continue_after_restart, CurrentVsn, Descr}),
+	    init:reboot(),
+	    {noreply, NS};
 	{'EXIT', Reason} ->
 	    io:format("release_handler:"
 		      "install_release(Vsn=~p Opts=~p) failed, "
@@ -950,7 +982,38 @@ do_install_release(#state{start_prg = StartPrg,
 	{value, Release} ->
 	    LatestRelease = get_latest_release(Releases),
 	    case get_rh_script(LatestRelease, Release, RelDir, Masters) of
+		{ok, {_CurrentVsn, _Descr, [restart_new_emulator|_Script]}}
+		  when Static == true ->
+		    throw(static_emulator);
+		{ok, {CurrentVsn, Descr, [restart_new_emulator|_Script]}} ->
+		    %% This will only happen if the upgrade includes
+		    %% an emulator upgrade (and it is not a downgrade)
+		    %% - then the new emulator must be started before
+		    %% new code can be loaded.
+		    %% Create a temporary release which includes new
+		    %% emulator, kernel, stdlib and sasl - and old
+		    %% versions of other applications.
+		    {TmpVsn,TmpRelease} =
+			new_emulator_make_tmp_release(LatestRelease,Release,
+						      RelDir,Opts,Masters),
+		    NReleases = [TmpRelease|Releases],
+
+		    %% Then uppgrade to the temporary release.
+		    %% The rest of the upgrade will continue after the restart
+		    prepare_restart_new_emulator(StartPrg, RootDir,
+						 RelDir, TmpVsn, TmpRelease,
+						 NReleases, Masters),
+		    {restart_new_emulator, CurrentVsn, Descr};
 		{ok, {CurrentVsn, Descr, Script}} ->
+		    %% In case there has been an emulator upgrade,
+		    %% remove the temporary release
+		    NReleases =
+			new_emulator_rm_tmp_release(
+			  LatestRelease#release.vsn,
+			  LatestRelease#release.erts_vsn,
+			  Vsn,RelDir,Releases,Masters),
+
+		    %% Then execute the relup script
 		    mon_nodes(true),
 		    EnvBefore = application_controller:prep_config_change(),
 		    Apps = change_appl_data(RelDir, Release, Masters),
@@ -958,31 +1021,19 @@ do_install_release(#state{start_prg = StartPrg,
 		    NewLibs = get_new_libs(LatestRelease#release.libs,
 					   Release#release.libs),
 		    case eval_script(Script, Apps, LibDirs, NewLibs, Opts) of
-			{ok, []} ->
-			    application_controller:config_change(EnvBefore),
-			    mon_nodes(false),
-			    NewReleases = set_status(Vsn, current, Releases),
-			    {ok, NewReleases, CurrentVsn, Descr};
 			{ok, Unpurged} ->
 			    application_controller:config_change(EnvBefore),
 			    mon_nodes(false),
-			    NewReleases = set_status(Vsn, current, Releases),
-			    {ok, NewReleases, Unpurged, CurrentVsn, Descr};
-			restart_new_emulator when Static == true ->
+			    NReleases1 = set_status(Vsn, current, NReleases),
+			    {ok, NReleases1, Unpurged, CurrentVsn, Descr};
+			restart_emulator when Static == true ->
 			    throw(static_emulator);
-			restart_new_emulator ->
+			restart_emulator ->
 			    mon_nodes(false),
-			    {value, PermanentRelease} = 
-				lists:keysearch(permanent, #release.status,
-						Releases), 
-			    NReleases = set_status(Vsn, current, Releases),
-			    NReleases2 = set_status(Vsn,tmp_current,NReleases),
-			    write_releases(RelDir, NReleases2, Masters),
 			    prepare_restart_new_emulator(StartPrg, RootDir,
-							 RelDir, Release,
-							 PermanentRelease, 
-							 Masters),
-			    {restart_new_emulator, CurrentVsn, Descr};
+							 RelDir, Vsn, Release,
+							 NReleases, Masters),
+			    {restart_emulator, CurrentVsn, Descr};
 			Else ->
 			    application_controller:config_change(EnvBefore),
 			    mon_nodes(false),
@@ -995,6 +1046,145 @@ do_install_release(#state{start_prg = StartPrg,
 	    {error, {no_such_release, Vsn}}
     end.
 
+new_emulator_make_tmp_release(CurrentRelease,ToRelease,RelDir,Opts,Masters) ->
+    CurrentVsn = CurrentRelease#release.vsn,
+    ToVsn = ToRelease#release.vsn,
+    TmpVsn = ?tmp_vsn(CurrentVsn),
+    BaseApps = [kernel,stdlib,sasl],
+    BaseLibs = [{App,Vsn,Lib} || {App,Vsn,Lib} <- ToRelease#release.libs,
+				 lists:member(App,BaseApps)],
+    check_base_libs(BaseLibs,ToVsn),
+    OldBaseLibs = [{App,Vsn,Lib} || {App,Vsn,Lib} <- CurrentRelease#release.libs,
+				    lists:member(App,BaseApps)],
+    check_base_libs(OldBaseLibs,CurrentVsn),
+    RestLibs = [{App,Vsn,Lib} || {App,Vsn,Lib} <- CurrentRelease#release.libs,
+				 not lists:member(App,BaseApps)],
+    TmpRelease = CurrentRelease#release{vsn=TmpVsn,
+					erts_vsn=ToRelease#release.erts_vsn,
+					libs = BaseLibs ++ RestLibs,
+					status = unpacked},
+    new_emulator_make_hybrid_boot(CurrentVsn,ToVsn,TmpVsn,BaseLibs,
+				  RelDir,Opts,Masters),
+    new_emulator_make_hybrid_config(CurrentVsn,ToVsn,TmpVsn,RelDir,Masters),
+    {TmpVsn,TmpRelease}.
+
+check_base_libs([_,_,_]=BaseLibs,_Vsn) ->
+    [Kernel,Sasl,Stdlib] = lists:keysort(1,BaseLibs),
+    [Kernel,Stdlib,Sasl];
+check_base_libs(SomeMissing,Vsn) ->
+    find_missing(SomeMissing,[kernel,stdlib,sasl],Vsn).
+
+find_missing(SomeMissing,[H|T],Vsn) ->
+    case lists:keymember(H,1,SomeMissing) of
+	true ->
+	    find_missing(SomeMissing,T,Vsn);
+	false ->
+	    throw({error,{missing_base_app,Vsn,H}})
+    end.
+
+new_emulator_make_hybrid_boot(CurrentVsn,ToVsn,TmpVsn,BaseLibs,RelDir,Opts,Masters) ->
+    FromBootFile = filename:join([RelDir,CurrentVsn,"start.boot"]),
+    ToBootFile = filename:join([RelDir,ToVsn,"start.boot"]),
+    TmpBootFile = filename:join([RelDir,TmpVsn,"start.boot"]),
+    ensure_dir(TmpBootFile,Masters),
+    Args = [ToVsn,Opts],
+    {ok,FromBoot} = read_file(FromBootFile,Masters),
+    {ok,ToBoot} = read_file(ToBootFile,Masters),
+    [KernelPath,SaslPath,StdlibPath] =
+	[filename:join(Path,ebin) || {_,_,Path} <- lists:keysort(1,BaseLibs)],
+    Paths = {KernelPath,StdlibPath,SaslPath},
+    case systools_make:make_hybrid_boot(TmpVsn,FromBoot,ToBoot,Paths,Args) of
+	{ok,TmpBoot} ->
+	    write_file(TmpBootFile,TmpBoot,Masters);
+	{error,Reason} ->
+	    throw({error,{could_not_create_hybrid_boot,Reason}})
+    end.
+
+new_emulator_make_hybrid_config(CurrentVsn,ToVsn,TmpVsn,RelDir,Masters) ->
+    FromFile = filename:join([RelDir,CurrentVsn,"sys.config"]),
+    ToFile = filename:join([RelDir,ToVsn,"sys.config"]),
+    TmpFile = filename:join([RelDir,TmpVsn,"sys.config"]),
+
+    FromConfig =
+	case consult(FromFile,Masters) of
+	    {ok,[FC]} ->
+		FC;
+	    {error,Error1} ->
+		io:format("Warning: ~p can not read ~p: ~p~n",
+			  [?MODULE,FromFile,Error1]),
+		[]
+	end,
+
+    [Kernel,Stdlib,Sasl] =
+	case consult(ToFile,Masters) of
+	    {ok,[ToConfig]} ->
+		[lists:keyfind(App,1,ToConfig) || App <- [kernel,stdlib,sasl]];
+	    {error,Error2} ->
+		io:format("Warning: ~p can not read ~p: ~p~n",
+			  [?MODULE,ToFile,Error2]),
+		[false,false,false]
+	end,
+
+    Config1 = replace_config(kernel,FromConfig,Kernel),
+    Config2 = replace_config(stdlib,Config1,Stdlib),
+    Config3 = replace_config(sasl,Config2,Sasl),
+
+    ConfigStr = io_lib:format("~p.~n",[Config3]),
+    write_file(TmpFile,ConfigStr,Masters).
+
+%% Take the configuration for application App from the new config and
+%% insert in the old config.
+%% If no entry exists in the new config, then delete the entry (if it exists)
+%% from the old config.
+%% If entry exists in the new config, but not in the old config, then
+%% add the entry.
+replace_config(App,Config,false) ->
+    lists:keydelete(App,1,Config);
+replace_config(App,Config,AppConfig) ->
+    lists:keystore(App,1,Config,AppConfig).
+
+%% Remove all files related to the temporary release
+new_emulator_rm_tmp_release(?tmp_vsn(_)=TmpVsn,EVsn,NewVsn,
+			    RelDir,Releases,Masters) ->
+    case os:type() of
+	{win32, nt} ->
+	    rename_tmp_service(EVsn,TmpVsn,NewVsn);
+	_ ->
+	    ok
+    end,
+    remove_dir(filename:join(RelDir,TmpVsn),Masters),
+    lists:keydelete(TmpVsn,#release.vsn,Releases);
+new_emulator_rm_tmp_release(_,_,_,_,Releases,_) ->
+    Releases.
+
+%% Rename the tempoarary service (for erts ugprade) to the real ToVsn
+rename_tmp_service(EVsn,TmpVsn,NewVsn) ->
+    FromName = hd(string:tokens(atom_to_list(node()),"@")) ++ "_" ++ TmpVsn,
+    ToName = hd(string:tokens(atom_to_list(node()),"@")) ++ "_" ++ NewVsn,
+    case erlsrv:get_service(EVsn,ToName) of
+	{error, _Error} ->
+	    ok;
+	_Data ->
+	    erlsrv:remove_service(ToName)
+    end,
+    rename_service(EVsn,FromName,ToName).
+
+
+%% Rename a service and check that it succeeded
+rename_service(EVsn,FromName,ToName) ->
+    case erlsrv:rename_service(EVsn,FromName,ToName) of
+	{ok,_} ->
+	    case erlsrv:get_service(EVsn,ToName) of
+		{error,Error1} ->
+		    throw({error,Error1});
+		_Data2 ->
+		    ok
+	    end;
+	Error2 ->
+	    throw({error,{service_rename_failed, Error2}})
+    end.
+
+
 %%% This code chunk updates the services in one of two ways,
 %%% Either the emulator is restarted, in which case the old service
 %%% is to be removed and the new enabled, or the emulator is NOT restarted
@@ -1011,26 +1201,16 @@ do_make_services_permanent(PermanentVsn,Vsn, PermanentEVsn, EVsn) ->
 	    %% rename.
 	    case os:getenv("ERLSRV_SERVICE_NAME") == PermName of
 		true ->
-		    case erlsrv:rename_service(EVsn,PermName,Name) of
-			{ok,_} ->
-			    case erlsrv:get_service(EVsn,Name) of
-				{error,Error2} ->
-				    throw({error,Error2});
-				_Data2 ->
-				    %% The interfaces for doing this are
-				    %% NOT published and may be subject to
-				    %% change. Do NOT do this anywhere else!
-
-				    os:putenv("ERLSRV_SERVICE_NAME", Name),
-
-				    %% Restart heart port program, this 
-				    %% function is only to be used here.
-				    heart:cycle(),
-				    ok
-			    end;
-			Error3 ->
-			    throw({error,{service_rename_failed, Error3}})
-		    end;
+		    rename_service(EVsn,PermName,Name),
+		    %% The interfaces for doing this are
+		    %% NOT published and may be subject to
+		    %% change. Do NOT do this anywhere else!
+
+		    os:putenv("ERLSRV_SERVICE_NAME", Name),
+
+		    %% Restart heart port program, this
+		    %% function is only to be used here.
+		    heart:cycle();
 		false ->
 		    throw({error,service_name_missmatch})
 	    end;
@@ -1269,21 +1449,31 @@ do_set_removed(RelDir, Vsn, Releases, Masters) ->
 %% corresponding relup instructions, we check if it's possible to
 %% downgrade from CurrentVsn to ToVsn.
 %%-----------------------------------------------------------------
+get_rh_script(#release{vsn = ?tmp_vsn(CurrentVsn)},
+	      #release{vsn = ToVsn},
+	      RelDir,
+	      Masters) ->
+    {ok,{Vsn,Descr,[restart_new_emulator|Script]}} =
+	do_get_rh_script(CurrentVsn,ToVsn,RelDir,Masters),
+    {ok,{Vsn,Descr,Script}};
 get_rh_script(#release{vsn = CurrentVsn},
-	      #release{vsn = Vsn},
+	      #release{vsn = ToVsn},
 	      RelDir,
 	      Masters) ->
-    Relup = filename:join([RelDir, Vsn, "relup"]),
-    case try_upgrade(Vsn, CurrentVsn, Relup, Masters) of
+    do_get_rh_script(CurrentVsn,ToVsn,RelDir,Masters).
+
+do_get_rh_script(CurrentVsn, ToVsn, RelDir, Masters) ->
+    Relup = filename:join([RelDir, ToVsn, "relup"]),
+    case try_upgrade(ToVsn, CurrentVsn, Relup, Masters) of
 	{ok, RhScript} ->
 	    {ok, RhScript};
 	_ ->
 	    Relup2 = filename:join([RelDir, CurrentVsn,"relup"]),
-	    case try_downgrade(Vsn, CurrentVsn, Relup2, Masters) of
+	    case try_downgrade(ToVsn, CurrentVsn, Relup2, Masters) of
 		{ok, RhScript} ->
 		    {ok, RhScript};
 		_ ->
-		    throw({error, {no_matching_relup, Vsn, CurrentVsn}})
+		    throw({error, {no_matching_relup, ToVsn, CurrentVsn}})
 	    end
     end.
 
@@ -1496,6 +1686,15 @@ prepare_restart_nt(#release{erts_vsn = EVsn, vsn = Vsn},
 %% restart is performed by calling init:reboot() higher up.
 %%-----------------------------------------------------------------
 prepare_restart_new_emulator(StartPrg, RootDir, RelDir,
+			     Vsn, Release, Releases, Masters) ->
+    {value, PRelease} = lists:keysearch(permanent, #release.status,Releases),
+    NReleases1 = set_status(Vsn, current, Releases),
+    NReleases2 = set_status(Vsn,tmp_current,NReleases1),
+    write_releases(RelDir, NReleases2, Masters),
+    prepare_restart_new_emulator(StartPrg, RootDir, RelDir,
+				 Release, PRelease, Masters).
+
+prepare_restart_new_emulator(StartPrg, RootDir, RelDir,
 			     Release, PRelease, Masters) ->
     #release{erts_vsn = EVsn, vsn = Vsn} = Release,
     Data = EVsn ++ " " ++ Vsn,
@@ -1521,19 +1720,10 @@ check_start_prg({do_check, StartPrg}, Masters) ->
 check_start_prg({_, StartPrg}, _) ->
     StartPrg.
 
-write_new_start_erl(Data, RelDir, false) ->
-    DataFile = filename:join([RelDir, "new_start_erl.data"]),
-    case do_write_file(DataFile, Data) of
-	ok    -> DataFile;
-	Error -> throw(Error)
-    end;
 write_new_start_erl(Data, RelDir, Masters) ->
     DataFile = filename:join([RelDir, "new_start_erl.data"]),
-    case at_all_masters(Masters, ?MODULE, do_write_file,
-			[DataFile, Data]) of
-	ok    -> DataFile;
-	Error -> throw(Error)
-    end.
+    write_file(DataFile, Data, Masters),
+    DataFile.
 
 %%-----------------------------------------------------------------
 %% When a new emulator shall be restarted, the current release
@@ -1547,27 +1737,41 @@ write_new_start_erl(Data, RelDir, Masters) ->
 %% If the release is made permanent, this is written to disk.
 %%-----------------------------------------------------------------
 transform_release(ReleaseDir, Releases, Masters) ->
-    F = fun(Release) when Release#release.status == tmp_current ->
-		Release#release{status = unpacked};
-	   (Release) -> Release
-	end,
-    case lists:map(F, Releases) of
-	Releases ->
-	    Releases;
-	DReleases ->
+    case init:script_id() of
+	{Name, ?tmp_vsn(_)=TmpVsn} ->
+	    %% This is was a reboot due to a new emulator version. The
+	    %% current release is a temporary internal release, which
+	    %% must be removed. It is the "real new release" that is
+	    %% set to unpacked on disk and current in memory.
+	    DReleases = lists:keydelete(TmpVsn,#release.vsn,Releases),
 	    write_releases(ReleaseDir, DReleases, Masters),
-	    F1 = fun(Release) when Release#release.status == tmp_current ->
-			 case init:script_id() of
-			     {_Name, Vsn} when Release#release.vsn == Vsn ->
-				 Release#release{status = current};
-			     _ ->
-				 Release#release{status = unpacked}
-			 end;
-		    (Release) -> Release
-		 end,
-	    lists:map(F1, Releases)
+	    set_current({Name,TmpVsn},Releases);
+	ScriptId ->
+	    F = fun(Release) when Release#release.status == tmp_current ->
+			Release#release{status = unpacked};
+		   (Release) -> Release
+		end,
+	    case lists:map(F, Releases) of
+		Releases ->
+		    Releases;
+		DReleases ->
+		    write_releases(ReleaseDir, DReleases, Masters),
+		    set_current(ScriptId, Releases)
+	    end
     end.
 
+set_current(ScriptId, Releases) ->
+    F1 = fun(Release) when Release#release.status == tmp_current ->
+		 case ScriptId of
+		     {_Name,Vsn} when Release#release.vsn == Vsn ->
+			 Release#release{status = current};
+		     _ ->
+			 Release#release{status = unpacked}
+		 end;
+	    (Release) -> Release
+	 end,
+    lists:map(F1, Releases).
+
 %%-----------------------------------------------------------------
 %% Functions handling files, RELEASES, start_erl.data etc.
 %% This functions consider if the release_handler is a client and
@@ -1626,12 +1830,25 @@ extract_tar(Root, Tar) ->
 	    throw({error, {cannot_extract_file, Name, Reason}})
     end.
 
-write_releases(Dir, NewReleases, false) ->
+write_releases(Dir, Releases, Masters) ->
+    %% We must never write 'current' to disk, since this will confuse
+    %% us after a node restart - since we would then have a permanent
+    %% release running, but state set to current for a non-running
+    %% release.
+    NewReleases = lists:zf(fun(Release) when Release#release.status == current ->
+				   {true, Release#release{status = unpacked}};
+			      (_) ->
+				   true
+			   end, Releases),
+    write_releases_1(Dir, NewReleases, Masters).
+
+
+write_releases_1(Dir, NewReleases, false) ->
     case do_write_release(Dir, "RELEASES", NewReleases) of
 	ok    -> ok;
 	Error -> throw(Error)
     end;
-write_releases(Dir, NewReleases, Masters) ->
+write_releases_1(Dir, NewReleases, Masters) ->
     all_masters(Masters),
     write_releases_m(Dir, NewReleases, Masters).
 
@@ -1853,6 +2070,37 @@ read_file(File, false) ->
 read_file(File, Masters) ->
     read_master(Masters, File).
 
+write_file(File, Data, false) ->
+    case file:write_file(File, Data) of
+	ok    -> ok;
+	Error -> throw(Error)
+    end;
+write_file(File, Data, Masters) ->
+    case at_all_masters(Masters, file, write_file, [File, Data]) of
+	ok    -> ok;
+	Error -> throw(Error)
+    end.
+
+ensure_dir(File, false) ->
+    case filelib:ensure_dir(File) of
+	ok -> ok;
+	Error -> throw(Error)
+    end;
+ensure_dir(File, Masters) ->
+    case at_all_masters(Masters,filelib,ensure_dir,[File]) of
+	ok -> ok;
+	Error -> throw(Error)
+    end.
+
+remove_dir(Dir, false) ->
+    remove_file(Dir);
+remove_dir(Dir, Masters) ->
+    case at_all_masters(Masters,?MODULE,remove_file,[Dir]) of
+	ok -> ok;
+	Error -> throw(Error)
+    end.
+
+
 %% Ignore status of each delete !
 remove_files(Master, Files, Masters) ->
     takewhile(Master, Masters, ?MODULE, do_remove_files, [Files]).
diff --git a/lib/sasl/src/release_handler_1.erl b/lib/sasl/src/release_handler_1.erl
index 8d0baf3ab1..b4b288646f 100644
--- a/lib/sasl/src/release_handler_1.erl
+++ b/lib/sasl/src/release_handler_1.erl
@@ -47,26 +47,38 @@
 %%%-----------------------------------------------------------------
 %%% This is a low-level release handler.
 %%%-----------------------------------------------------------------
+check_script([restart_new_emulator|Script], LibDirs) ->
+    %% There is no need to check for old processes, since the node
+    %% will be restarted before anything else happens.
+    do_check_script(Script, LibDirs, []);
 check_script(Script, LibDirs) ->
     case catch check_old_processes(Script,soft_purge) of
 	{ok, PurgeMods} ->
-	    {Before, _After} = split_instructions(Script),
-	    case catch lists:foldl(fun(Instruction, EvalState1) ->
-					   eval(Instruction, EvalState1)
-				   end,
-				   #eval_state{libdirs = LibDirs},
-				   Before) of
-		EvalState2 when is_record(EvalState2, eval_state) ->
-		    {ok,PurgeMods};
-		{error, Error} ->
-		    {error, Error};
-		Other ->
-		    {error, Other}
-	    end;
+	    do_check_script(Script, LibDirs, PurgeMods);
 	{error, Mod} ->
 	    {error, {old_processes, Mod}}
     end.
 
+do_check_script(Script, LibDirs, PurgeMods) ->
+    {Before, After} = split_instructions(Script),
+    case catch lists:foldl(fun(Instruction, EvalState1) ->
+				   eval(Instruction, EvalState1)
+			   end,
+			   #eval_state{libdirs = LibDirs},
+			   Before) of
+	       EvalState2 when is_record(EvalState2, eval_state) ->
+		 case catch syntax_check_script(After) of
+		     ok ->
+			 {ok,PurgeMods};
+		     Other ->
+			 {error,Other}
+		 end;
+	       {error, Error} ->
+		 {error, Error};
+	       Other ->
+		 {error, Other}
+	 end.
+
 %% eval_script/1 - For testing only - no apps added, just testing instructions
 eval_script(Script) ->
     eval_script(Script, [], [], [], []).
@@ -83,22 +95,30 @@ eval_script(Script, Apps, LibDirs, NewLibs, Opts) ->
 					       newlibs = NewLibs,
 					       opts = Opts},
 				   Before) of
-		EvalState2 when is_record(EvalState2, eval_state) ->
-		    case catch lists:foldl(fun(Instruction, EvalState3) ->
-						   eval(Instruction, EvalState3)
-					   end,
-					   EvalState2,
-					   After) of
-			EvalState4 when is_record(EvalState4, eval_state) ->
-			    {ok, EvalState4#eval_state.unpurged};
-			restart_new_emulator ->
-			    restart_new_emulator;
-			Error ->
-			    {'EXIT', Error}
-		    end;
-		{error, Error} -> {error, Error};
-		Other -> {error, Other}
-	    end;
+		       EvalState2 when is_record(EvalState2, eval_state) ->
+			 case catch syntax_check_script(After) of
+			     ok ->
+				 case catch lists:foldl(
+					      fun(Instruction, EvalState3) ->
+						      eval(Instruction,
+							   EvalState3)
+					      end,
+					      EvalState2,
+					      After) of
+				     EvalState4
+				       when is_record(EvalState4, eval_state) ->
+					 {ok, EvalState4#eval_state.unpurged};
+				     restart_emulator ->
+					 restart_emulator;
+				     Error ->
+					 {'EXIT', Error}
+				 end;
+			     Other ->
+				 {error,Other}
+			 end;
+		       {error, Error} -> {error, Error};
+		       Other -> {error, Other}
+		 end;
 	{error, Mod} ->
 	    {error, {old_processes, Mod}}
     end.
@@ -174,6 +194,42 @@ do_check_old_code(Mod,Procs) ->
     [Mod].
 
 
+%% Check the last part of the script, i.e. the part after point_of_no_return.
+%% More or less a syntax check in case the script was handwritten.
+syntax_check_script([point_of_no_return | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{load, {_,_,_}} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{remove, {_,_,_}} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{purge, _} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{suspend, _} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{resume, _} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{code_change, _} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{code_change, _, _} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{stop, _} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{start, _} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{sync_nodes, _, {_,_,_}} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{sync_nodes, _, _} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([{apply, {_,_,_}} | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([restart_emulator | Script]) ->
+    syntax_check_script(Script);
+syntax_check_script([Illegal | _Script]) ->
+    throw({illegal_instruction_after_point_of_no_return,Illegal});
+syntax_check_script([]) ->
+    ok.
+
+
 %%-----------------------------------------------------------------
 %% An unpurged module is a module for which there exist an old
 %% version of the code.  This should only be the case if there are
@@ -243,7 +299,7 @@ do_check_old_code(Mod,Procs) ->
 %%    must also exectue the same line.  Waits for all these nodes to get
 %%    to this line.
 %% point_of_no_return
-%% restart_new_emulator
+%% restart_emulator
 %% {stop_application, Appl}     - Impl with apply
 %% {unload_application, Appl}   - Impl with {remove..}
 %% {load_application, Appl}     - Impl with {load..}
@@ -402,8 +458,8 @@ eval({sync_nodes, Id, Nodes}, EvalState) ->
 eval({apply, {M, F, A}}, EvalState) ->
     apply(M, F, A),
     EvalState;
-eval(restart_new_emulator, _EvalState) ->
-    throw(restart_new_emulator).
+eval(restart_emulator, _EvalState) ->
+    throw(restart_emulator).
 
 get_opt(Tag, EvalState, Default) ->
     case lists:keysearch(Tag, 1, EvalState#eval_state.opts) of
diff --git a/lib/sasl/src/sasl.appup.src b/lib/sasl/src/sasl.appup.src
index 64c653a4e5..ce4aa1f8f8 100644
--- a/lib/sasl/src/sasl.appup.src
+++ b/lib/sasl/src/sasl.appup.src
@@ -1,25 +1,27 @@
-%%
+%% -*- erlang -*-
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 1999-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 1999-2011. 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
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
-%% %CopyrightEnd%
 %%
-
+%% %CopyrightEnd%
 {"%VSN%",
- [{"2.1.4", [{load_module, release_handler},
-	     {load_module, systools_relup}]}],
- [{"2.1.4", [{load_module, release_handler},
-	     {load_module, systools_relup}]}]
+ %% Up from - max two major revisions back
+ [{<<"2\\.2(\\.[0-9]+)*">>,[restart_new_emulator]},         %% R15
+  {<<"2\\.1\\.10(\\.[0-9]+)*">>,[restart_new_emulator]},    %% R14B04 (and later?)
+  {<<"2\\.1\\.[6-9](\\.[0-9]+)*">>,[restart_new_emulator]}],%% R13B-R14B03
+ %% Down to - max two major revisions back
+ [{<<"2\\.2(\\.[0-9]+)*">>,[restart_new_emulator]},         %% R15
+  {<<"2\\.1\\.10(\\.[0-9]+)*">>,[restart_new_emulator]},    %% R14B04 (and later?)
+  {<<"2\\.1\\.[6-9](\\.[0-9]+)*">>,[restart_new_emulator]}] %% R13B-R14B03
 }.
diff --git a/lib/sasl/src/systools_make.erl b/lib/sasl/src/systools_make.erl
index 7f400f5cce..ce37f3c2ce 100644
--- a/lib/sasl/src/systools_make.erl
+++ b/lib/sasl/src/systools_make.erl
@@ -31,6 +31,8 @@
 
 -export([read_application/4]).
 
+-export([make_hybrid_boot/5]).
+
 -import(lists, [filter/2, keysort/2, keysearch/3, map/2, reverse/1,
 		append/1, foldl/3,  member/2, foreach/2]).
 
@@ -162,6 +164,118 @@ return({error,Mod,Error},_,Flags) ->
 	    error
     end.
 
+
+%%-----------------------------------------------------------------
+%% Make hybrid boot file for upgrading emulator. The resulting boot
+%% file is a combination of the two input files, where kernel, stdlib
+%% and sasl versions are taken from the second file (the boot file of
+%% the new release), and all other application versions from the first
+%% file (the boot file of the old release).
+%%
+%% The most important thing that can fail here is that the input boot
+%% files do not contain all three base applications - kernel, stdlib
+%% and sasl.
+%%
+%% TmpVsn = string(),
+%% Paths = {KernelPath,StdlibPath,SaslPath}
+%% Returns {ok,Boot} | {error,Reason}
+%% Boot1 = Boot2 = Boot = binary()
+%% Reason = {app_not_found,App} | {app_not_replaced,App}
+%% App = kernel | stdlib | sasl
+make_hybrid_boot(TmpVsn, Boot1, Boot2, Paths, Args) ->
+    catch do_make_hybrid_boot(TmpVsn, Boot1, Boot2, Paths, Args).
+do_make_hybrid_boot(TmpVsn, Boot1, Boot2, Paths, Args) ->
+    {script,{_RelName1,_RelVsn1},Script1} = binary_to_term(Boot1),
+    {script,{RelName2,_RelVsn2},Script2} = binary_to_term(Boot2),
+    MatchPaths = get_regexp_path(Paths),
+    NewScript1 = replace_paths(Script1,MatchPaths),
+    {Kernel,Stdlib,Sasl} = get_apps(Script2,undefined,undefined,undefined),
+    NewScript2 = replace_apps(NewScript1,Kernel,Stdlib,Sasl),
+    NewScript3 = add_apply_upgrade(NewScript2,Args),
+    Boot = term_to_binary({script,{RelName2,TmpVsn},NewScript3}),
+    {ok,Boot}.
+
+%% For each app, compile a regexp that can be used for finding its path
+get_regexp_path({KernelPath,StdlibPath,SaslPath}) ->
+    {ok,KernelMP} = re:compile("kernel-[0-9\.]+",[unicode]),
+    {ok,StdlibMP} = re:compile("stdlib-[0-9\.]+",[unicode]),
+    {ok,SaslMP} = re:compile("sasl-[0-9\.]+",[unicode]),
+    [{KernelMP,KernelPath},{StdlibMP,StdlibPath},{SaslMP,SaslPath}].
+
+%% For each path in the script, check if it matches any of the MPs
+%% found above, and if so replace it with the correct new path.
+replace_paths([{path,Path}|Script],MatchPaths) ->
+    [{path,replace_path(Path,MatchPaths)}|replace_paths(Script,MatchPaths)];
+replace_paths([Stuff|Script],MatchPaths) ->
+    [Stuff|replace_paths(Script,MatchPaths)];
+replace_paths([],_) ->
+    [].
+
+replace_path([Path|Paths],MatchPaths) ->
+    [do_replace_path(Path,MatchPaths)|replace_path(Paths,MatchPaths)];
+replace_path([],_) ->
+    [].
+
+do_replace_path(Path,[{MP,ReplacePath}|MatchPaths]) ->
+    case re:run(Path,MP,[{capture,none}]) of
+	nomatch -> do_replace_path(Path,MatchPaths);
+	match -> ReplacePath
+    end;
+do_replace_path(Path,[]) ->
+    Path.
+
+%% Return the entries for loading the three base applications
+get_apps([{kernelProcess,application_controller,
+	   {application_controller,start,[{application,kernel,_}]}}=Kernel|
+	  Script],_,Stdlib,Sasl) ->
+    get_apps(Script,Kernel,Stdlib,Sasl);
+get_apps([{apply,{application,load,[{application,stdlib,_}]}}=Stdlib|Script],
+	 Kernel,_,Sasl) ->
+    get_apps(Script,Kernel,Stdlib,Sasl);
+get_apps([{apply,{application,load,[{application,sasl,_}]}}=Sasl|_Script],
+	 Kernel,Stdlib,_) ->
+    {Kernel,Stdlib,Sasl};
+get_apps([_|Script],Kernel,Stdlib,Sasl) ->
+    get_apps(Script,Kernel,Stdlib,Sasl);
+get_apps([],undefined,_,_) ->
+    throw({error,{app_not_found,kernel}});
+get_apps([],_,undefined,_) ->
+    throw({error,{app_not_found,stdlib}});
+get_apps([],_,_,undefined) ->
+    throw({error,{app_not_found,sasl}}).
+
+
+%% Replace the entries for loading the base applications
+replace_apps([{kernelProcess,application_controller,
+	       {application_controller,start,[{application,kernel,_}]}}|
+	      Script],Kernel,Stdlib,Sasl) ->
+    [Kernel|replace_apps(Script,undefined,Stdlib,Sasl)];
+replace_apps([{apply,{application,load,[{application,stdlib,_}]}}|Script],
+	     Kernel,Stdlib,Sasl) ->
+    [Stdlib|replace_apps(Script,Kernel,undefined,Sasl)];
+replace_apps([{apply,{application,load,[{application,sasl,_}]}}|Script],
+	     _Kernel,_Stdlib,Sasl) ->
+    [Sasl|Script];
+replace_apps([Stuff|Script],Kernel,Stdlib,Sasl) ->
+    [Stuff|replace_apps(Script,Kernel,Stdlib,Sasl)];
+replace_apps([],undefined,undefined,_) ->
+    throw({error,{app_not_replaced,sasl}});
+replace_apps([],undefined,_,_) ->
+    throw({error,{app_not_replaced,stdlib}});
+replace_apps([],_,_,_) ->
+    throw({error,{app_not_replaced,kernel}}).
+
+
+%% Finally add an apply of release_handler:new_emulator_upgrade - which will
+%% complete the execution of the upgrade script (relup).
+add_apply_upgrade(Script,Args) ->
+    [{progress, started} | RevScript] = lists:reverse(Script),
+    lists:reverse([{progress,started},
+		   {apply,{release_handler,new_emulator_upgrade,Args}} |
+		   RevScript]).
+
+
+
 %%-----------------------------------------------------------------
 %% Create a release package from a release file.
 %% Options is a list of {path, Path} | silent |
@@ -250,13 +364,13 @@ get_release(File, Path, ModTestP, Machine) ->
     end.
 	
 get_release1(File, Path, ModTestP, Machine) ->
-    {ok, Release} = read_release(File, Path),
+    {ok, Release, Warnings1} = read_release(File, Path),
     {ok, Appls0} = collect_applications(Release, Path),
     {ok, Appls1} = check_applications(Appls0),
     {ok, Appls2} = sort_included_applications(Appls1, Release), % OTP-4121
-    {ok, Warnings} = check_modules(Appls2, Path, ModTestP, Machine),
+    {ok, Warnings2} = check_modules(Appls2, Path, ModTestP, Machine),
     {ok, Appls} = sort_appls(Appls2),
-    {ok, Release, Appls, Warnings}.
+    {ok, Release, Appls, Warnings1 ++ Warnings2}.
 
 %%______________________________________________________________________
 %% read_release(File, Path) -> {ok, #release} | throw({error, What})
@@ -271,11 +385,12 @@ read_release(File, Path) ->
 
 check_rel(Release) ->
     case catch check_rel1(Release) of
-	{ok, {Name,Vsn,Evsn,Appl,Incl}} ->
+	{ok, {Name,Vsn,Evsn,Appl,Incl}, Ws} ->
 	    {ok, #release{name=Name, vsn=Vsn,
 			  erts_vsn=Evsn,
 			  applications=Appl,
-			  incl_apps=Incl}};
+			  incl_apps=Incl},
+	    Ws};
 	{error, Error} ->
 	    throw({error,?MODULE,Error});
 	Error ->
@@ -286,8 +401,8 @@ check_rel1({release,{Name,Vsn},{erts,EVsn},Appl}) when is_list(Appl) ->
     check_name(Name),
     check_vsn(Vsn),
     check_evsn(EVsn),
-    {Appls,Incls} = check_appl(Appl),
-    {ok, {Name,Vsn,EVsn,Appls,Incls}};
+    {{Appls,Incls},Ws} = check_appl(Appl),
+    {ok, {Name,Vsn,EVsn,Appls,Incls},Ws};
 check_rel1(_) ->
     {error, badly_formatted_release}.
 
@@ -340,8 +455,8 @@ check_appl(Appl) ->
 		end,
 		Appl) of
 	[] ->
-	    mandatory_applications(Appl),
-	    split_app_incl(Appl);
+	    {ok,Ws} = mandatory_applications(Appl),
+	    {split_app_incl(Appl),Ws};
 	Illegal ->
 	    throw({error, {illegal_applications,Illegal}})
     end.
@@ -352,7 +467,12 @@ mandatory_applications(Appl) ->
     Mand = mandatory_applications(),
     case filter(fun(X) -> member(X, AppNames) end, Mand) of
 	Mand ->
-	    ok;
+	    case member(sasl,AppNames) of
+		true ->
+		    {ok,[]};
+		_ ->
+		    {ok, [{warning,missing_sasl}]}
+	    end;
 	_ ->
 	    throw({error, {missing_mandatory_app, Mand}})
     end.
@@ -2198,5 +2318,9 @@ form_warn(Prefix, {exref_undef, Undef}) ->
 			      [Prefix,M,F,A])
 	end,
     map(F, Undef);
+form_warn(Prefix, missing_sasl) ->
+    io_lib:format("~s: Missing application sasl. "
+		  "Can not upgrade with this release~n",
+		  [Prefix]);
 form_warn(Prefix, What) ->
     io_lib:format("~s ~p~n", [Prefix,What]).
diff --git a/lib/sasl/src/systools_rc.erl b/lib/sasl/src/systools_rc.erl
index daadb79967..c16f6aa845 100644
--- a/lib/sasl/src/systools_rc.erl
+++ b/lib/sasl/src/systools_rc.erl
@@ -54,6 +54,7 @@
 %% {sync_nodes, Id, Nodes}
 %% {apply, {M, F, A}}
 %% restart_new_emulator
+%% restart_emulator
 %%-----------------------------------------------------------------
 
 %% High-level instructions that contain dependencies
@@ -144,7 +145,10 @@ translate_merged_script(Mode, Script, Appls, PreAppls) ->
     {Before2, After2} = translate_dependent_instrs(Mode, Before1, After1, 
 						  Appls),
     Before3 = merge_load_object_code(Before2),
-    NewScript = Before3 ++ [point_of_no_return | After2],
+
+    {Before4,After4} = sort_emulator_restart(Mode,Before3,After2),
+    NewScript = Before4 ++ [point_of_no_return | After4],
+
     check_syntax(NewScript),
     {ok, NewScript}.
 
@@ -699,6 +703,39 @@ mlo([{load_object_code, {Lib, LibVsn, Mods}} | T]) ->
 mlo([]) -> [].
 
 %%-----------------------------------------------------------------
+%% RESTART EMULATOR
+%% -----------------------------------------------------------------
+%% -----------------------------------------------------------------
+%% Check if there are any 'restart_new_emulator' instructions (i.e. if
+%% the emulator or core application version is changed). If so, this
+%% must be done first for upgrade and last for downgrade.
+%% Check if there are any 'restart_emulator' instructions, if so
+%% remove all and place one the end.
+%% -----------------------------------------------------------------
+sort_emulator_restart(Mode,Before,After) ->
+    {Before1,After1} =
+	case filter_out(restart_new_emulator, After) of
+	    After ->
+		{Before,After};
+	    A1 when Mode==up ->
+		{[restart_new_emulator|Before],A1};
+	    A1 when Mode==dn ->
+		{Before,A1++[restart_emulator]}
+	end,
+    After2 =
+	case filter_out(restart_emulator, After1) of
+	    After1 ->
+		After1;
+	    A2 ->
+		A2++[restart_emulator]
+	end,
+    {Before1,After2}.
+
+
+filter_out(What,List) ->
+    lists:filter(fun(X) when X=:=What -> false; (_) -> true end, List).
+
+%%-----------------------------------------------------------------
 %% SYNTAX CHECK
 %%-----------------------------------------------------------------
 %%-----------------------------------------------------------------
@@ -817,6 +854,7 @@ check_op({apply, {M, F, A}}) ->
     check_func(F),
     check_args(A);
 check_op(restart_new_emulator) -> ok;
+check_op(restart_emulator) -> ok;
 check_op(X) -> throw({error, {bad_instruction, X}}).
 
 check_mod(Mod) when is_atom(Mod) -> ok;
diff --git a/lib/sasl/src/systools_relup.erl b/lib/sasl/src/systools_relup.erl
index 6d9e922900..7fb623bb85 100644
--- a/lib/sasl/src/systools_relup.erl
+++ b/lib/sasl/src/systools_relup.erl
@@ -112,6 +112,11 @@
 -export([mk_relup/3, mk_relup/4, format_error/1, format_warning/1]).
 -include("systools.hrl").
 
+-define(R15_SASL_VSN,"2.2").
+
+%% For test purposes only - used by kernel, stdlib and sasl tests
+-export([appup_search_for_version/2]).
+
 %%-----------------------------------------------------------------
 %% mk_relup(TopRelFile, BaseUpRelDcs, BaseDnRelDcs)
 %% mk_relup(TopRelFile, BaseUpRelDcs, BaseDnRelDcs, Opts) -> Ret
@@ -200,7 +205,13 @@ do_mk_relup(TopRelFile, BaseUpRelDcs, BaseDnRelDcs, Path, Opts) ->
 	%% TopRel = #release
 	%% NameVsnApps = [{{Name, Vsn}, #application}]
 	{ok, TopRel, NameVsnApps, Ws0} ->
-	    %%
+	    case lists:member({warning,missing_sasl},Ws0) of
+		true ->
+		    throw({error,?MODULE,{missing_sasl,TopRel}});
+		false ->
+		    ok
+	    end,
+
 	    %% TopApps = [#application]
 	    TopApps = lists:map(fun({_, App}) -> App end, NameVsnApps),
 
@@ -247,7 +258,21 @@ foreach_baserel_up(TopRel, TopApps, [BaseRelDc|BaseRelDcs], Path, Opts,
 	       Ws, Acc) ->
     BaseRelFile = extract_filename(BaseRelDc),
 
-    {ok, BaseRel} = systools_make:read_release(BaseRelFile, Path),
+    {BaseRel, {BaseNameVsns, BaseApps}, Ws0} =
+	case systools_make:get_release(BaseRelFile, Path) of
+	    {ok, BR, NameVsnApps, Warns} ->
+		case lists:member({warning,missing_sasl},Warns) of
+		    true ->
+			throw({error,?MODULE,{missing_sasl,BR}});
+		    false ->
+			%% NameVsnApps = [{{Name,Vsn},#application}]
+			%% Gives two lists - [{Name,Vsn}] and [#application]
+			{BR,lists:unzip(NameVsnApps),Warns}
+		end;
+	    Other1 ->
+		throw(Other1)
+	end,
+
 
     %%
     %% BaseRel = #release
@@ -257,29 +282,23 @@ foreach_baserel_up(TopRel, TopApps, [BaseRelDc|BaseRelDcs], Path, Opts,
     %% application, one for each added applications, and one for
     %% each removed applications.
     %%
-    {RUs1, Ws1} = collect_appup_scripts(up, TopApps, BaseRel, Ws, []),
+    {RUs1, Ws1} = collect_appup_scripts(up, TopApps, BaseRel, Ws0++Ws, []),
 
     {RUs2, Ws2} = create_add_app_scripts(BaseRel, TopRel, RUs1, Ws1),
 
     {RUs3, Ws3} = create_remove_app_scripts(BaseRel, TopRel, RUs2, Ws2),
 
-    {RUs4, Ws4} = 
-	check_for_emulator_restart(TopRel, BaseRel, RUs3, Ws3, Opts),
-
-    BaseApps =
-	case systools_make:get_release(BaseRelFile, Path) of
-	    {ok, _, NameVsnApps, _Warns} ->
-		lists:map(fun({_,App}) -> App end, NameVsnApps);
-	    Other1 ->
-		throw(Other1)
-	end,
+    {RUs4, Ws4} = check_for_emulator_restart(TopRel, BaseRel, RUs3, Ws3, Opts),
 
     case systools_rc:translate_scripts(up, RUs4, TopApps, BaseApps) of
-	{ok, RUs} ->
+	{ok, RUs5} ->
+
+	    {RUs, Ws5} = fix_r15_sasl_upgrade(RUs5,Ws4,BaseNameVsns),
+
 	    VDR = {BaseRel#release.vsn,
 		   extract_description(BaseRelDc), RUs},
 	    foreach_baserel_up(TopRel, TopApps, BaseRelDcs, Path, 
-			       Opts, Ws4, [VDR| Acc]);
+			       Opts, Ws5, [VDR| Acc]);
 	XXX ->
 	    throw(XXX)
     end;
@@ -294,42 +313,41 @@ foreach_baserel_dn(TopRel, TopApps, [BaseRelDc|BaseRelDcs], Path, Opts,
 	       Ws, Acc) ->
     BaseRelFile = extract_filename(BaseRelDc),
 
-    {ok, BaseRel} = systools_make:read_release(BaseRelFile, Path),
-
-    %% BaseRel = #release
-
-    %% RUs = (release upgrade scripts)
-    %%
-    {RUs1, Ws1} = collect_appup_scripts(dn, TopApps, BaseRel, Ws, []),
-
-    {BaseApps, Ws2} =
+    {BaseRel, BaseApps, Ws0} =
 	case systools_make:get_release(BaseRelFile, Path) of
 	    %%
 	    %% NameVsnApps = [{{Name, Vsn}, #application}]
-	    {ok, _, NameVsnApps, Warns} ->
-		%%
-		%% NApps = [#application]
-		NApps = lists:map(fun({_,App}) -> App end, NameVsnApps),
-		{NApps, Warns ++ Ws1};
+	    {ok, BR, NameVsnApps, Warns} ->
+		case lists:member({warning,missing_sasl},Warns) of
+		    true ->
+			throw({error,?MODULE,{missing_sasl,BR}});
+		    false ->
+			%% NApps = [#application]
+			NApps = lists:map(fun({_,App}) -> App end, NameVsnApps),
+			{BR, NApps, Warns}
+		end;
 	    Other ->
 		throw(Other)
 	end,
 
-    RUs2 = RUs1,
+    %% BaseRel = #release
+
+    %% RUs = (release upgrade scripts)
+    %%
+    {RUs1, Ws1} = collect_appup_scripts(dn, TopApps, BaseRel, Ws0++Ws, []),
 
-    {RUs3, Ws3} = create_add_app_scripts(TopRel, BaseRel, RUs2, Ws2),
+    {RUs2, Ws2} = create_add_app_scripts(TopRel, BaseRel, RUs1, Ws1),
 
-    {RUs4, Ws4} = create_remove_app_scripts(TopRel, BaseRel, RUs3, Ws3),
+    {RUs3, Ws3} = create_remove_app_scripts(TopRel, BaseRel, RUs2, Ws2),
 
-    {RUs5, Ws5} = check_for_emulator_restart(TopRel, BaseRel,
-					     RUs4, Ws4, Opts),
+    {RUs4, Ws4} = check_for_emulator_restart(TopRel, BaseRel, RUs3, Ws3, Opts),
 
-    case systools_rc:translate_scripts(dn, RUs5, BaseApps, TopApps) of
+    case systools_rc:translate_scripts(dn, RUs4, BaseApps, TopApps) of
 	{ok, RUs} ->
 	    VDR = {BaseRel#release.vsn,
 		   extract_description(BaseRelDc), RUs},
 	    foreach_baserel_dn(TopRel, TopApps, BaseRelDcs, Path, 
-			       Opts, Ws5, [VDR| Acc]);
+			       Opts, Ws4, [VDR| Acc]);
 	XXX -> 
 	    throw(XXX)
     end;
@@ -343,14 +361,42 @@ foreach_baserel_dn( _, _, [], _, _, Ws, Acc) ->
 %%
 check_for_emulator_restart(#release{erts_vsn = Vsn1, name = N1}, 
                            #release{erts_vsn = Vsn2, name = N2}, RUs, Ws, 
-                           _Opts) when Vsn1 /= Vsn2 ->
-    {RUs++[[restart_new_emulator]], [{erts_vsn_changed, {N1, N2}} | Ws]};
+                           Opts) when Vsn1 /= Vsn2 ->
+    %% Automatically insert a restart_new_emulator instruction when
+    %% erts version is changed. Also allow extra restart at the end of
+    %% the upgrade if restart_emulator option is given.
+    NewRUs = [[restart_new_emulator]|RUs],
+    NewWs = [{erts_vsn_changed, {{N1,Vsn1}, {N2,Vsn2}}} | Ws],
+    check_for_restart_emulator_opt(NewRUs, NewWs, Opts);
 check_for_emulator_restart(_, _, RUs, Ws, Opts) ->
+    check_for_restart_emulator_opt(RUs, Ws, Opts).
+
+check_for_restart_emulator_opt(RUs, Ws, Opts) ->
     case get_opt(restart_emulator, Opts) of
-	true -> {RUs++[[restart_new_emulator]], Ws};
+	true -> {RUs++[[restart_emulator]], Ws};
 	_ -> {RUs, Ws}
     end.
 
+
+%% Special handling of the upgrade from pre R15 to post R15. In R15,
+%% upgrade of the emulator was improved by moving the restart of the
+%% emulator before the rest of the upgrade instructions. However, it
+%% can only work if the release_handler is already upgraded to a post
+%% R15 version. If not, the upgrade instructions must be backwards
+%% compatible - i.e. restart_new_emulator will be the last
+%% instruction, executed after all code loading, code_change etc.
+fix_r15_sasl_upgrade([restart_new_emulator | RestRUs]=RUs, Ws, BaseApps) ->
+    case lists:keyfind(sasl,1,BaseApps) of
+	{sasl,Vsn} when Vsn < ?R15_SASL_VSN ->
+	    {lists:delete(restart_emulator,RestRUs) ++ [restart_new_emulator],
+	     [pre_R15_emulator_upgrade|Ws]};
+	_ ->
+	    {RUs,Ws}
+    end;
+fix_r15_sasl_upgrade(RUs, Ws, _BaseApps) ->
+    {RUs,Ws}.
+
+
 %% collect_appup_scripts(Mode, TopApps, BaseRel, Ws, RUs) -> {NRUs, NWs}
 %% Mode = up | dn
 %% TopApps = [#application]
@@ -440,13 +486,32 @@ get_script_from_appup(Mode, TopApp, BaseVsn, Ws, RUs) ->
 		  %% XXX Why is this a warning only?
 		  [{bad_vsn, {TopVsn, TopApp#application.vsn}}| Ws]
 	  end,
-    case lists:keysearch(BaseVsn, 1, VsnRUs) of
-	{value, {_, RU}} ->
+    case appup_search_for_version(BaseVsn, VsnRUs) of
+	{ok, RU} ->
 	    {RUs ++ [RU], Ws1};
-	_ ->
+	error ->
 	    throw({error, ?MODULE, {no_relup, FName, TopApp, BaseVsn}})
     end.
 
+appup_search_for_version(BaseVsn, VsnRUs) ->
+    appup_search_for_version(BaseVsn, length(BaseVsn), VsnRUs).
+
+appup_search_for_version(BaseVsn,_,[{BaseVsn,RU}|_]) ->
+    {ok,RU};
+appup_search_for_version(BaseVsn,Size,[{Vsn,RU}|VsnRUs]) when is_binary(Vsn) ->
+    case re:run(BaseVsn,Vsn,[unicode,{capture,first,index}]) of
+	{match,[{0,Size}]} ->
+	    {ok, RU};
+	_ ->
+	    appup_search_for_version(BaseVsn,Size,VsnRUs)
+    end;
+appup_search_for_version(BaseVsn,Size,[_|VsnRUs]) ->
+    appup_search_for_version(BaseVsn,Size,VsnRUs);
+appup_search_for_version(_,_,[]) ->
+    error.
+
+
+
 
 %% Primitives for the "lists of release names" that we upgrade from
 %% and to.
@@ -543,7 +608,9 @@ format_error({no_relup, File, App, Vsn}) ->
 		  "in file ~p~n",
 		  [App#application.name, App#application.vsn, 
 		   App#application.name, Vsn, File]);
-
+format_error({missing_sasl,Release}) ->
+    io_lib:format("No sasl application in release ~p, ~p. Can not be upgraded.",
+		  [Release#release.name, Release#release.vsn]);
 format_error(Error) ->
     io:format("~p~n", [Error]).