1 files changed, 33 insertions, 2 deletions
diff --git a/lib/compiler/test/beam_type_SUITE.erl b/lib/compiler/test/beam_type_SUITE.erl
index 882e281a44..076a604aa4 100644
--- a/lib/compiler/test/beam_type_SUITE.erl
+++ b/lib/compiler/test/beam_type_SUITE.erl
@@ -24,7 +24,7 @@
 	 integers/1,numbers/1,coverage/1,booleans/1,setelement/1,
 	 cons/1,tuple/1,record_float/1,binary_float/1,float_compare/1,
 	 arity_checks/1,elixir_binaries/1,find_best/1,
-         test_size/1,cover_lists_functions/1]).
+         test_size/1,cover_lists_functions/1,list_append/1,bad_binary_unit/1]).
 
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
@@ -47,7 +47,9 @@ groups() ->
        elixir_binaries,
        find_best,
        test_size,
-       cover_lists_functions
+       cover_lists_functions,
+       list_append,
+       bad_binary_unit
       ]}].
 
 init_per_suite(Config) ->
@@ -271,8 +273,22 @@ setelement(_Config) ->
     T0 = id({a,42}),
     {a,_} = T0,
     {b,_} = setelement(1, T0, b),
+    {z,b} = do_setelement_1(<<(id(1)):32>>, {a,b}, z),
+    {new,two} = do_setelement_2(<<(id(1)):1>>, {one,two}, new),
     ok.
 
+do_setelement_1(<<N:32>>, Tuple, NewValue) ->
+    _ = element(N, Tuple),
+    %% While updating the type for Tuple, beam_ssa_type would do:
+    %%   maps:without(lists:seq(0, 4294967295), Elements)
+    setelement(N, Tuple, NewValue).
+
+do_setelement_2(<<N:1>>, Tuple, NewValue) ->
+    %% Cover the second clause in remove_element_info/2. The
+    %% type for the second element will be kept.
+    two = element(2, Tuple),
+    setelement(N, Tuple, NewValue).
+
 cons(_Config) ->
     [did] = cons(assigned, did),
 
@@ -487,5 +503,20 @@ cover_lists_functions(Config) ->
     true = is_list(Zipped),
     ok.
 
+list_append(_Config) ->
+    %% '++'/2 has a quirk where it returns the right-hand argument as-is when
+    %% the left-hand is [].
+    hello = id([]) ++ id(hello),
+    ok.
+
+%% OTP-15872: The compiler would treat the "Unit" of bs_init instructions as
+%% the unit of the result instead of the required unit of the input, causing
+%% is_binary checks to be wrongly optimized away.
+bad_binary_unit(_Config) ->
+    Bin = id(<<1,2,3>>),
+    Bitstring = <<Bin/binary,1:1>>,
+    false = is_binary(Bitstring),
+    ok.
+
 id(I) ->
     I.