1 files changed, 66 insertions, 3 deletions

diff --git a/lib/compiler/test/beam_utils_SUITE.erl b/lib/compiler/test/beam_utils_SUITE.erl
index 3d35b546fc..ff0f72d519 100644
--- a/lib/compiler/test/beam_utils_SUITE.erl
+++ b/lib/compiler/test/beam_utils_SUITE.erl
@@ -25,13 +25,13 @@
 	 is_not_killed/1,is_not_used_at/1,
 	 select/1,y_catch/1,otp_8949_b/1,liveopt/1,coverage/1,
          y_registers/1,user_predef/1,scan_f/1,cafu/1,
-         receive_label/1,read_size_file_version/1,not_used/1]).
+         receive_label/1,read_size_file_version/1,not_used/1,
+         is_used_fr/1,unsafe_is_function/1]).
 -export([id/1]).
 
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() ->
-    test_lib:recompile(?MODULE),
     [{group,p}].
 
 groups() ->
@@ -52,10 +52,13 @@ groups() ->
        scan_f,
        cafu,
        read_size_file_version,
-       not_used
+       not_used,
+       is_used_fr,
+       unsafe_is_function
       ]}].
 
 init_per_suite(Config) ->
+    test_lib:recompile(?MODULE),
     Config.
 
 end_per_suite(_Config) ->
@@ -132,6 +135,15 @@ bs_init(_Config) ->
     <<"foo/foo">> = do_bs_init_4(<<"foo">>, true),
     error = do_bs_init_4([], not_boolean),
 
+    Id = 17575,
+    Domain = -8798798,
+    [<<10,1:16,Id:16/signed>>,<<8,2:16,Domain:32/signed>>] =
+        do_bs_init_5(#{tag=>value,id=>Id,domain=>Domain}),
+    {'EXIT',{{required,id},[_|_]}} =
+        (catch do_bs_init_5(#{tag=>value,id=>nil,domain=>Domain})),
+    {'EXIT',{{required,domain},[_|_]}} =
+        (catch do_bs_init_5(#{tag=>value,id=>Id,domain=>nil})),
+
     ok.
 
 do_bs_init_1([?MODULE], Sz) ->
@@ -189,6 +201,20 @@ do_bs_init_4(Arg1, Arg2) ->
             error
     end.
 
+do_bs_init_5(#{tag := value, id := Id, domain := Domain}) ->
+    [case Id of
+         nil ->
+             error(id({required, id}));
+         _ ->
+             <<10, 1:16/signed, Id:16/signed>>
+     end,
+     case Domain of
+         nil ->
+             error(id({required, domain}));
+         _ ->
+             <<8, 2:16/signed, Domain:32/signed>>
+     end].
+
 bs_save(_Config) ->
     {a,30,<<>>} = do_bs_save(<<1:1,30:5>>),
     {b,127,<<>>} = do_bs_save(<<1:1,31:5,0:1,127:7>>),
@@ -527,5 +553,42 @@ not_used_p(_C, S, K, L) when is_record(K, k) ->
             id(K)
     end.
 
+is_used_fr(Config) ->
+    1 = is_used_fr(self(), self()),
+    1 = is_used_fr(self(), other),
+    receive 1 -> ok end,
+    receive 1 -> ok end,
+    receive 1 -> ok end,
+    receive 1 -> ok end,
+    ok.
+
+is_used_fr(X, Y) ->
+    %% beam_utils:is_used({fr,R}, Code) would crash.
+    _ = 0 / (X ! 1),
+    _ = case Y of
+            X -> ok;
+            _ -> error
+        end,
+    X ! 1.
+
+%% ERL-778.
+unsafe_is_function(Config) ->
+    {undefined,any} = unsafe_is_function(undefined, any),
+    {ok,any} = unsafe_is_function(fun() -> ok end, any),
+    {'EXIT',{{case_clause,_},_}} = (catch unsafe_is_function(fun(_) -> ok end, any)),
+    ok.
+
+unsafe_is_function(F, M) ->
+    %% There would be an internal consistency failure:
+    %%   Instruction: {bif,is_function,{f,0},[{x,0},{integer,0}],{x,2}}
+    %%   Error:       {uninitialized_reg,{y,0}}:
+
+    NewValue = case is_function(F, 0) of
+                true -> F();
+                false when F =:= undefined -> undefined
+            end,
+    {NewValue,M}.
+
+
 %% The identity function.
 id(I) -> I.