1 files changed, 62 insertions, 2 deletions
diff --git a/lib/kernel/test/kernel_SUITE.erl b/lib/kernel/test/kernel_SUITE.erl
index 16b6c54939..0f29d895e5 100644
--- a/lib/kernel/test/kernel_SUITE.erl
+++ b/lib/kernel/test/kernel_SUITE.erl
@@ -32,7 +32,7 @@
 -export([init_per_testcase/2, end_per_testcase/2]).
 
 % Test cases must be exported.
--export([app_test/1]).
+-export([app_test/1, appup_test/1]).
 
 %%
 %% all/1
@@ -40,7 +40,7 @@
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
-    [app_test].
+    [app_test, appup_test].
 
 groups() -> 
     [].
@@ -76,3 +76,63 @@ app_test(suite) ->
 app_test(Config) when is_list(Config) ->
     ?line ok=?t:app_test(kernel),
     ok.
+
+
+%% Test that appup allows upgrade from/downgrade to a maximum of two
+%% major releases back.
+appup_test(_Config) ->
+    application:load(kernel),
+    {_,_,Vsn} = lists:keyfind(kernel,1,application:loaded_applications()),
+    AppupFile = filename:join([code:lib_dir(kernel),ebin,"kernel.appup"]),
+    {ok,[{Vsn,UpFrom,DownTo}=AppupScript]} = file:consult(AppupFile),
+    ct:log("~p~n",[AppupScript]),
+    {OkVsns,NokVsns} = create_test_vsns(Vsn),
+    check_appup(OkVsns,UpFrom,{ok,[restart_new_emulator]}),
+    check_appup(OkVsns,DownTo,{ok,[restart_new_emulator]}),
+    check_appup(NokVsns,UpFrom,error),
+    check_appup(NokVsns,DownTo,error),
+    ok.
+
+create_test_vsns(Current) ->
+    [XStr,YStr|Rest] = string:tokens(Current,"."),
+    X = list_to_integer(XStr),
+    Y = list_to_integer(YStr),
+    SecondMajor = vsn(X,Y-2),
+    SecondMinor = SecondMajor ++ ".1.3",
+    FirstMajor = vsn(X,Y-1),
+    FirstMinor = FirstMajor ++ ".57",
+    ThisMajor = vsn(X,Y),
+    This =
+	case Rest of
+	    [] ->
+		[];
+	    ["1"] ->
+		[ThisMajor];
+	    _ ->
+		ThisMinor = ThisMajor ++ ".1",
+		[ThisMajor,ThisMinor]
+	end,
+    OkVsns = This ++ [FirstMajor, FirstMinor, SecondMajor, SecondMinor],
+
+    ThirdMajor = vsn(X,Y-3),
+    ThirdMinor = ThirdMajor ++ ".10.12",
+    Illegal = ThisMajor ++ ",1",
+    Newer1Major = vsn(X,Y+1),
+    Newer1Minor = Newer1Major ++ ".1",
+    Newer2Major = ThisMajor ++ "1",
+    NokVsns = [ThirdMajor,ThirdMinor,
+	       Illegal,
+	       Newer1Major,Newer1Minor,
+	       Newer2Major],
+    {OkVsns,NokVsns}.
+
+vsn(X,Y) ->
+    integer_to_list(X) ++ "." ++ integer_to_list(Y).
+
+check_appup([Vsn|Vsns],Instrs,Expected) ->
+    case systools_relup:appup_search_for_version(Vsn, Instrs) of
+	Expected -> check_appup(Vsns,Instrs,Expected);
+	Other -> ct:fail({unexpected_result_for_vsn,Vsn,Other})
+    end;
+check_appup([],_,_) ->
+    ok.