Fix release_handler:upgrade_app and downgrade_app when upgrading emulator

Changes to the mechanism for upgrading the emulator in OTP R15 was
erronously not handled in release_handler:upgrade_app, downgrade_app,
upgrade_script and downgrade_script. This has been corrected,
including test and documentation.

1 files changed, 35 insertions, 0 deletions

diff --git a/lib/sasl/test/release_handler_SUITE_data/app1_app2/lib4/app1-4.0/src/app1_server.erl b/lib/sasl/test/release_handler_SUITE_data/app1_app2/lib4/app1-4.0/src/app1_server.erl
new file mode 100644
index 0000000000..660d095ebf
--- /dev/null
+++ b/lib/sasl/test/release_handler_SUITE_data/app1_app2/lib4/app1-4.0/src/app1_server.erl
@@ -0,0 +1,35 @@
+-module(app1_server).
+
+-behaviour(gen_server).
+
+%% API
+-export([start_link/0]).
+
+%% gen_server callbacks
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
+	 terminate/2, code_change/3]).
+
+start_link() ->
+    gen_server:start_link({local, harry}, ?MODULE, [], []).
+
+init([]) ->
+    {ok, []}.
+
+handle_call(error, _From, State) ->
+    Reply = error,
+    {reply, Reply, State};
+handle_call(_Request, _From, State) ->
+    Reply = ok,
+    {reply, Reply, State}.
+
+handle_cast(_Msg, State) ->
+    {noreply, State}.
+
+handle_info(_Info, State) ->
+    {noreply, State}.
+
+terminate(_Reason, _State) ->
+    ok.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.