erl_types: Normalise X:=none() pairs in t_map/3

t_map/3 previously required callers to perform this normalisation, but
as t_from_form/5 would sometimes fail to do so, this requirement is
relaxed.

Bug (ERL-177) reported and shrunk by Luke Imhoff.

3 files changed, 22 insertions, 10 deletions

diff --git a/lib/dialyzer/test/map_SUITE_data/src/mand_remote_val/a.erl b/lib/dialyzer/test/map_SUITE_data/src/mand_remote_val/a.erl
new file mode 100644
index 0000000000..827984b20b
--- /dev/null
+++ b/lib/dialyzer/test/map_SUITE_data/src/mand_remote_val/a.erl
@@ -0,0 +1,9 @@
+-module(a).
+-export([to_map/1, to_map/2]).
+-type t() :: #{type := b:t()}.
+
+-spec to_map(t()) -> map().
+to_map(Resource) -> to_map(Resource, #{}).
+
+-spec to_map(t(), map()) -> map().
+to_map(_, Map) when is_map(Map) -> #{}.
diff --git a/lib/dialyzer/test/map_SUITE_data/src/mand_remote_val/b.erl b/lib/dialyzer/test/map_SUITE_data/src/mand_remote_val/b.erl
new file mode 100644
index 0000000000..31f9bb6b3e
--- /dev/null
+++ b/lib/dialyzer/test/map_SUITE_data/src/mand_remote_val/b.erl
@@ -0,0 +1,3 @@
+-module(b).
+-export_type([t/0]).
+-type t() :: binary().
diff --git a/lib/hipe/cerl/erl_types.erl b/lib/hipe/cerl/erl_types.erl
index 7826dada9d..243bb6e25d 100644
--- a/lib/hipe/cerl/erl_types.erl
+++ b/lib/hipe/cerl/erl_types.erl
@@ -1664,10 +1664,12 @@ t_map(Pairs0, DefK0, DefV0) ->
   %% define(DEBUG, true).
   try
     validate_map_elements(Pairs)
-  catch error:badarg ->      error(badarg,      [Pairs0,DefK0,DefV0]);
-	error:{badarg, E} -> error({badarg, E}, [Pairs0,DefK0,DefV0])
+  catch error:badarg -> error(badarg, [Pairs0,DefK0,DefV0])
   end,
-  ?map(Pairs, DefK, DefV).
+  case map_pairs_are_none(Pairs) of
+    true -> ?none;
+    false -> ?map(Pairs, DefK, DefV)
+  end.
 
 normalise_map_optionals([], _, _) -> [];
 normalise_map_optionals([E={K,?opt,?none}|T], DefK, DefV) ->
@@ -1684,7 +1686,6 @@ normalise_map_optionals([E={K,?opt,V}|T], DefK, DefV) ->
 normalise_map_optionals([E|T], DefK, DefV) ->
   [E|normalise_map_optionals(T, DefK, DefV)].
 
-validate_map_elements([{_,?mand,?none}|_]) -> error({badarg, none_in_mand});
 validate_map_elements([{K1,_,_}|Rest=[{K2,_,_}|_]]) ->
   case is_singleton_type(K1) andalso K1 < K2 of
     false -> error(badarg);
@@ -1697,6 +1698,10 @@ validate_map_elements([{K,_,_}]) ->
   end;
 validate_map_elements([]) -> true.
 
+map_pairs_are_none([]) -> false;
+map_pairs_are_none([{_,?mand,?none}|_]) -> true;
+map_pairs_are_none([_|Ps]) -> map_pairs_are_none(Ps).
+
 -spec t_is_map(erl_type()) -> boolean().
 
 t_is_map(Type) ->
@@ -2833,12 +2838,7 @@ t_inf(?map(_, ADefK, ADefV) = A, ?map(_, BDefK, BDefV) = B, _Opaques) ->
 	 %% becomes mandatory in the infinumum
 	 (K, _, V1, _, V2) -> {K, ?mand, t_inf(V1, V2)}
       end, A, B),
-  %% If the infinimum of any mandatory values is ?none, the entire map infinimum
-  %% is ?none.
-  case lists:any(fun({_,?mand,?none})->true; ({_,_,_}) -> false end, Pairs) of
-    true -> t_none();
-    false -> t_map(Pairs, t_inf(ADefK, BDefK), t_inf(ADefV, BDefV))
-  end;
+  t_map(Pairs, t_inf(ADefK, BDefK), t_inf(ADefV, BDefV));
 t_inf(?matchstate(Pres1, Slots1), ?matchstate(Pres2, Slots2), _Opaques) ->
   ?matchstate(t_inf(Pres1, Pres2), t_inf(Slots1, Slots2));
 t_inf(?nil, ?nil, _Opaques) -> ?nil;