3 files changed, 42 insertions, 1 deletions
diff --git a/lib/asn1/src/asn1ct_check.erl b/lib/asn1/src/asn1ct_check.erl
index 5d8740b92e..45f1d3a8c9 100644
--- a/lib/asn1/src/asn1ct_check.erl
+++ b/lib/asn1/src/asn1ct_check.erl
@@ -6581,6 +6581,8 @@ merge_tags2([T1= #tag{type='IMPLICIT'}, T2 |Rest], Acc) ->
     merge_tags2([T1#tag{type=T2#tag.type, form=T2#tag.form}|Rest],Acc);
 merge_tags2([T1= #tag{type={default,'IMPLICIT'}}, T2 |Rest], Acc) ->
     merge_tags2([T1#tag{type=T2#tag.type, form=T2#tag.form}|Rest],Acc);
+merge_tags2([T1= #tag{type={default,'AUTOMATIC'}}, T2 |Rest], Acc) ->
+    merge_tags2([T1#tag{type=T2#tag.type, form=T2#tag.form}|Rest],Acc);
 merge_tags2([H|T],Acc) ->
     merge_tags2(T, [H|Acc]);
 merge_tags2([], Acc) ->
diff --git a/lib/asn1/test/asn1_SUITE.erl b/lib/asn1/test/asn1_SUITE.erl
index 888339a4d2..432197eec0 100644
--- a/lib/asn1/test/asn1_SUITE.erl
+++ b/lib/asn1/test/asn1_SUITE.erl
@@ -60,7 +60,8 @@ groups() ->
      {ber, Parallel,
       [ber_choiceinseq,
        % Uses 'SOpttest'
-       ber_optional]},
+       ber_optional,
+       tagdefault_automatic]},
 
      {app_test, [], [{asn1_app_test, all}]},
 
@@ -659,6 +660,19 @@ ber_optional(Config, Rule, Opts) ->
               {'C', asn1_NOVALUE, 111, asn1_NOVALUE}},
     asn1_test_lib:roundtrip('SOpttest', 'S', V).
 
+tagdefault_automatic(Config) ->
+    test(Config, fun tagdefault_automatic/3, [ber]).
+tagdefault_automatic(Config, Rule, Opts) ->
+    asn1_test_lib:compile("TAGDEFAULT-AUTOMATIC", Config, [Rule|Opts]),
+    << 48,8,128,2,100,101,129,2,110,111 >> =
+	asn1_test_lib:roundtrip_enc('TAGDEFAULT-AUTOMATIC', 'Tagged', {'Tagged', << 100,101 >>, << 110,111 >>}),
+    << 48,8,128,2,100,101,129,2,110,111 >> =
+	asn1_test_lib:roundtrip_enc('TAGDEFAULT-AUTOMATIC', 'Untagged', {'Untagged', << 100,101 >>, << 110,111 >>}),
+    << 48,8,4,2,100,101,130,2,110,111 >> =
+	asn1_test_lib:roundtrip_enc('TAGDEFAULT-AUTOMATIC', 'Mixed', {'Mixed', << 100,101 >>, << 110,111 >>}),
+
+    ok.
+
 %% records used by test-case default
 -record('Def1', {bool0,
                  bool1 = asn1_DEFAULT,
diff --git a/lib/asn1/test/asn1_SUITE_data/TAGDEFAULT-AUTOMATIC.asn b/lib/asn1/test/asn1_SUITE_data/TAGDEFAULT-AUTOMATIC.asn
new file mode 100644
index 0000000000..2fcba1f71e
--- /dev/null
+++ b/lib/asn1/test/asn1_SUITE_data/TAGDEFAULT-AUTOMATIC.asn
@@ -0,0 +1,25 @@
+TAGDEFAULT-AUTOMATIC DEFINITIONS AUTOMATIC TAGS ::=
+BEGIN
+
+EXPORTS
+	Tagged,
+	Untagged,
+	Mixed
+;
+
+Tagged ::= SEQUENCE {
+	o0	[0]	OCTET STRING,
+	o1	[1]	OCTET STRING
+}
+
+Untagged ::= SEQUENCE {
+	o0		OCTET STRING,
+	o1		OCTET STRING
+}
+
+Mixed ::= SEQUENCE {
+	o0		OCTET STRING,
+	o2	[2]	OCTET STRING
+}
+
+END