Fix crash when using remote types in the tail of list types

Hans Bolider reported a dialyzer crash when using a remote type in
the tail position of a maybe_improper_list() declaration. A test
was created (by extending an existing module of the testsuite)
and erl_types was modified to expand the remote type and not pass
it unexpanded to subsequent phases in the processing.

1 files changed, 14 insertions, 3 deletions

diff --git a/lib/dialyzer/test/small_SUITE_data/src/maybe_improper.erl b/lib/dialyzer/test/small_SUITE_data/src/maybe_improper.erl
index 1743d81493..6d2a35b7c8 100644
--- a/lib/dialyzer/test/small_SUITE_data/src/maybe_improper.erl
+++ b/lib/dialyzer/test/small_SUITE_data/src/maybe_improper.erl
@@ -1,7 +1,18 @@
+%%%========================================================================
+%%% Tests handling of maybe improper lists
+%%%========================================================================
 -module(maybe_improper).
 
--export([s/1]).
+-export([s/1, t/0]).
 
 -spec s(maybe_improper_list(X,Y)) -> {[X], maybe_improper_list(X,Y)}.
-s(A) ->
-    lists:split(2,A).
+s(L) ->
+    lists:split(2, L).
+
+%% Having a remote type in the 'tail' of the list crashed dialyzer.
+%% The problem was fixed for R16B03.
+-type t_mil() :: maybe_improper_list(integer(), orddict:orddict()).
+
+-spec t() -> t_mil().
+t() ->
+    [42 | []].