Fix broken handling of default values in extensions for PER

Default values have never worked in extension for PER.

Note that for default values in the root part of SEQUENCE,
giving a value equal to the DEFAULT value, will result in
the same encoding as if asn1_DEFAULT was given. However,
that behavior is not promised by the documentation. The
documentation says that asn1_DEFAULT should be used for
default values. For DEFAULT in extensions, only implement
what the documentation promises and nothing more.

ERIERL-60

1 files changed, 53 insertions, 0 deletions

diff --git a/lib/asn1/test/testExtensionDefault.erl b/lib/asn1/test/testExtensionDefault.erl
new file mode 100644
index 0000000000..cc50fa95b8
--- /dev/null
+++ b/lib/asn1/test/testExtensionDefault.erl
@@ -0,0 +1,53 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+%%
+-module(testExtensionDefault).
+
+-export([main/1]).
+
+main(_Erule) ->
+    roundtrip('Message', {'Message',1,low}),    %Will be explicitly encoded.
+    roundtrip('Message', {'Message',1,high}),
+    roundtrip('Message', {'Message',1,asn1_DEFAULT}, {'Message',1,low}),
+
+    map_roundtrip('Message', #{id=>1,priority=>low}), %Will be explicitly encoded.
+    map_roundtrip('Message', #{id=>1,priority=>high}),
+    map_roundtrip('Message', #{id=>1}, #{id=>1,priority=>low}),
+    ok.
+
+roundtrip(Type, Value) ->
+    asn1_test_lib:roundtrip('ExtensionDefault', Type, Value).
+
+roundtrip(Type, Value, Expected) ->
+    %% asn1_test_lib:roundtrip/3 will invoke map_roundtrip/3, which will
+    %% not work in this case. Therefore, implement the roundtrip ourselves.
+    M = 'ExtensionDefault',
+    {ok,Enc} = M:encode(Type, Value),
+    {ok,Expected} = M:decode(Type, Enc),
+    ok.
+
+map_roundtrip(Type, Value) ->
+    map_roundtrip(Type, Value, Value).
+
+map_roundtrip(Type, Value, Expected) ->
+    M = 'maps_ExtensionDefault',
+    Enc = M:encode(Type, Value),
+    Expected = M:decode(Type, Enc),
+    ok.