1 files changed, 40 insertions, 3 deletions
diff --git a/lib/compiler/test/core_fold_SUITE.erl b/lib/compiler/test/core_fold_SUITE.erl
index dfff8236e8..30d145582a 100644
--- a/lib/compiler/test/core_fold_SUITE.erl
+++ b/lib/compiler/test/core_fold_SUITE.erl
@@ -28,7 +28,7 @@
 	 mixed_matching_clauses/1,unnecessary_building/1,
 	 no_no_file/1,configuration/1,supplies/1,
          redundant_stack_frame/1,export_from_case/1,
-         empty_values/1]).
+         empty_values/1,cover_letrec_effect/1]).
 
 -export([foo/0,foo/1,foo/2,foo/3]).
 
@@ -37,7 +37,6 @@
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
-    test_lib:recompile(?MODULE),
     [{group,p}].
 
 groups() -> 
@@ -49,10 +48,11 @@ groups() ->
        mixed_matching_clauses,unnecessary_building,
        no_no_file,configuration,supplies,
        redundant_stack_frame,export_from_case,
-       empty_values]}].
+       empty_values,cover_letrec_effect]}].
 
 
 init_per_suite(Config) ->
+    test_lib:recompile(?MODULE),
     Config.
 
 end_per_suite(_Config) ->
@@ -278,6 +278,8 @@ coverage(Config) when is_list(Config) ->
     a = cover_remove_non_vars_alias({a,b,c}),
     error = cover_will_match_lit_list(),
     {ok,[a]} = cover_is_safe_bool_expr(a),
+    false = cover_is_safe_bool_expr2(a),
+    ok = cover_eval_is_function(fun id/1),
 
     ok = cover_opt_guard_try(#cover_opt_guard_try{list=[a]}),
     error = cover_opt_guard_try(#cover_opt_guard_try{list=[]}),
@@ -341,6 +343,15 @@ cover_is_safe_bool_expr(X) ->
 	    false
     end.
 
+cover_is_safe_bool_expr2(X) ->
+    try
+	V = [X],
+    is_function(V, 1)
+    catch
+	_:_ ->
+	    false
+    end.
+
 cover_opt_guard_try(Msg) ->
     if
 	length(Msg#cover_opt_guard_try.list) =/= 1 ->
@@ -349,6 +360,12 @@ cover_opt_guard_try(Msg) ->
 	    ok
     end.
 
+cover_eval_is_function(X) ->
+    case X of
+        {a,_} -> is_function(X);
+        _ -> ok
+    end.
+
 bsm_an_inlined(<<_:8>>, _) -> ok;
 bsm_an_inlined(_, _) -> error.
 
@@ -598,5 +615,25 @@ empty_values(_Config) ->
 do_empty_values() when (#{})#{} ->
     c.
 
+cover_letrec_effect(_Config) ->
+    self() ! {tag,42},
+    _ = try
+            try
+                ignore
+            after
+                receive
+                    {tag,Int}=Term ->
+                        Res = #{k => {Term,<<Int:16>>}},
+                        self() ! Res
+                end
+            end
+        after
+            ok
+        end,
+    receive
+        Any ->
+            #{k := {{tag,42},<<42:16>>}} = Any
+    end,
+    ok.
 
 id(I) -> I.