Fix halfword bug in enif_make_int64

The bug was creating an invalid bignum instead of a small integer,
causing strange comparing behavior (=:= failed but == succeeded).

erts/emulator/beam/erl_nif.c

@@ -833,8 +833,11 @@ ERL_NIF_TERM enif_make_uint(ErlNifEnv* env, unsigned i)
 
 ERL_NIF_TERM enif_make_long(ErlNifEnv* env, long i)
 {
+    if (IS_SSMALL(i)) {
+	return make_small(i);
+    }
 #if SIZEOF_LONG == ERTS_SIZEOF_ETERM
-    return IS_SSMALL(i) ? make_small(i) : small_to_big(i, alloc_heap(env,2));
+    return small_to_big(i, alloc_heap(env,2));
 #elif SIZEOF_LONG == 8
     ensure_heap(env,3);
     return erts_sint64_to_big(i, &env->hp);
@@ -843,8 +846,11 @@ ERL_NIF_TERM enif_make_long(ErlNifEnv* env, long i)
 
 ERL_NIF_TERM enif_make_ulong(ErlNifEnv* env, unsigned long i)
 {
+    if (IS_USMALL(0,i)) {
+	return make_small(i);
+    }
 #if SIZEOF_LONG == ERTS_SIZEOF_ETERM
-    return IS_USMALL(0,i) ? make_small(i) : uint_to_big(i,alloc_heap(env,2));
+    return uint_to_big(i,alloc_heap(env,2));
 #elif SIZEOF_LONG == 8
     ensure_heap(env,3);
     return erts_uint64_to_big(i, &env->hp);    

erts/emulator/test/nif_SUITE.erl

@@ -257,10 +257,48 @@ types(Config) when is_list(Config) ->
                   end,
                   [{},{ok},{{}},{[],{}},{1,2,3,4,5}]),
     Stuff = [[],{},0,0.0,(1 bsl 100),(fun()-> ok end),make_ref(),self()],
-    [eq_cmp(A,clone(B)) || A<-Stuff, B<-Stuff],                   
+    [eq_cmp(A,clone(B)) || A<-Stuff, B<-Stuff],
+
+    {IntSz, LongSz} = type_sizes(),
+    UintMax = (1 bsl (IntSz*8)) - 1,
+    IntMax = UintMax bsr 1,
+    IntMin = -(IntMax+1),
+    UlongMax = (1 bsl (LongSz*8)) - 1,
+    LongMax = UlongMax bsr 1,
+    LongMin = -(LongMax+1),
+    Uint64Max = (1 bsl 64) - 1,
+    Int64Max = Uint64Max bsr 1,
+    Int64Min = -(Int64Max+1),
+    Limits = [{IntMin,IntMax},{0,UintMax},{LongMin,LongMax},{0,UlongMax},{Int64Min,Int64Max},{0,Uint64Max}],
+    io:format("Limits = ~p\n", [Limits]),
+    lists:foreach(fun(I) ->
+			  R1 = echo_int(I),
+			  %%io:format("echo_int(~p) -> ~p\n", [I, R1]),
+			  R2 = my_echo_int(I, Limits),
+			  ?line R1 = R2,
+			  ?line true = (R1 =:= R2),
+			  ?line true = (R1 == R2)
+		  end, int_list()),
+
     ?line verify_tmpmem(TmpMem),
     ok.
 
+int_list() ->
+    Start = 1 bsl 200,
+    int_list([Start], -Start).
+int_list([N | _]=List, End) when N<End ->
+    List;
+int_list([N | _]=List, End) ->
+    int_list([N - (1 + (abs(N) div 3)) | List], End).
+
+my_echo_int(I, Limits) ->
+    lists:map(fun({Min,Max}) ->
+		      if I < Min -> false;
+			 I > Max -> false;
+			 true -> I
+		      end
+	      end, Limits).
+
 clone(X) ->
     binary_to_term(term_to_binary(X)).
 
@@ -1269,6 +1307,8 @@ send_blob_thread(_,_,_) -> ?nif_stub.
 join_send_thread(_) -> ?nif_stub.
 copy_blob(_) -> ?nif_stub.
 send_term(_,_) -> ?nif_stub.
+echo_int(_) -> ?nif_stub.
+type_sizes() -> ?nif_stub.
 
 nif_stub_error(Line) ->
     exit({nif_not_loaded,module,?MODULE,line,Line}).

erts/emulator/test/nif_SUITE_data/nif_SUITE.c

@@ -28,6 +28,7 @@
 static int static_cntA; /* zero by default */
 static int static_cntB = NIF_SUITE_LIB_VER * 100;
 
+static ERL_NIF_TERM atom_false;
 static ERL_NIF_TERM atom_self;
 static ERL_NIF_TERM atom_ok;
 static ERL_NIF_TERM atom_join;
@@ -103,7 +104,7 @@ static int load(ErlNifEnv* env, void** priv_data, ERL_NIF_TERM load_info)
     msgenv_resource_type =  enif_open_resource_type(env,NULL,"nif_SUITE.msgenv",
 						    msgenv_dtor,
 						    ERL_NIF_RT_CREATE, NULL);
-
+    atom_false = enif_make_atom(env,"false");
     atom_self = enif_make_atom(env,"self");
     atom_ok = enif_make_atom(env,"ok");
     atom_join = enif_make_atom(env,"join");
@@ -481,6 +482,45 @@ static ERL_NIF_TERM type_test(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[
     return enif_make_atom(env,"error");
 }
 
+static ERL_NIF_TERM echo_int(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    int sint;
+    unsigned uint;
+    long slong;
+    unsigned long ulong;
+    ErlNifSInt64 sint64;
+    ErlNifUInt64 uint64;    
+    ERL_NIF_TERM sint_term = atom_false,   uint_term = atom_false;
+    ERL_NIF_TERM slong_term = atom_false,  ulong_term = atom_false;
+    ERL_NIF_TERM sint64_term = atom_false, uint64_term = atom_false;
+
+    if (enif_get_int(env, argv[0], &sint)) {
+	sint_term = enif_make_int(env, sint);
+    }
+    if (enif_get_uint(env, argv[0], &uint)) {
+	uint_term = enif_make_uint(env, uint);
+    }
+    if (enif_get_long(env, argv[0], &slong)) {
+	slong_term = enif_make_long(env, slong);
+    }
+    if (enif_get_ulong(env, argv[0], &ulong)) {
+	ulong_term = enif_make_ulong(env, ulong);
+    }
+    if (enif_get_int64(env, argv[0], &sint64)) {
+	sint64_term = enif_make_int64(env, sint64);
+    }
+    if (enif_get_uint64(env, argv[0], &uint64)) {
+	uint64_term = enif_make_uint64(env, uint64);
+    }
+    return enif_make_list6(env, sint_term, uint_term, slong_term, ulong_term, sint64_term, uint64_term);
+}
+
+static ERL_NIF_TERM type_sizes(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    return enif_make_tuple2(env, enif_make_int(env, sizeof(int)),
+			    enif_make_int(env, sizeof(long)));
+}
+
 static ERL_NIF_TERM tuple_2_list(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     int arity = -1;
@@ -1417,7 +1457,9 @@ static ErlNifFunc nif_funcs[] =
     {"send_blob_thread", 3, send_blob_thread},
     {"join_send_thread", 1, join_send_thread},
     {"copy_blob", 1, copy_blob},
-    {"send_term", 2, send_term}
+    {"send_term", 2, send_term},
+    {"echo_int", 1, echo_int},
+    {"type_sizes", 0, type_sizes}
 };
 
 ERL_NIF_INIT(nif_SUITE,nif_funcs,load,reload,upgrade,unload)