Fix CI failure

Signed-off-by: Fred Dushin <fred@dushin.net>

src/libAtomVM/otp_socket.c

@@ -1765,7 +1765,7 @@ static term nif_socket_recv_without_peek(Context *ctx, struct SocketResource *rs
     GlobalContext *global = ctx->global;
 
     size_t buffer_size = len == 0 ? rsrc_obj->buf_size : len;
-    char *buffer = malloc(buffer_size);
+    uint8_t *buffer = (uint8_t *) malloc(buffer_size);
     term payload = term_invalid_term();
 
     if (IS_NULL_PTR(buffer)) {

tests/libs/estdlib/test_tcp_socket.erl

@@ -27,6 +27,7 @@ test() ->
     ok = test_shutdown(),
     ok = test_close_by_another_process(),
     ok = test_buf_size(),
+    ok = test_override_buf_size(),
     case get_otp_version() of
         atomvm ->
             ok = test_abandon_select();
@@ -135,16 +136,31 @@ test_buf_size() ->
 
     %% we should only be able to receive
     ok = check_receive(Socket, Packet, 0, <<"0123456789">>),
+    ok = check_receive(Socket, Packet, 0, <<"0123456789">>),
+    ok = check_receive(Socket, Packet, 0, <<"0123456789">>),
+
+    ok = close_client_socket(Socket),
+
+    close_listen_socket(ListenSocket).
+
+test_override_buf_size() ->
+    etest:flush_msg_queue(),
+
+    Port = 44404,
+    ListenSocket = start_echo_server(Port),
+
+    {ok, Socket} = socket:open(inet, stream, tcp),
+    ok = try_connect(Socket, Port, 10),
+
+    %% limit the recv buffer size to 10 bytes
+    ok = socket:setopt(Socket, {otp, rcvbuf}, 10),
 
-    %% read the remaining 20 bytes
-    _ = socket:recv(Socket, 20),
+    Packet = "012345678901234567890123456789",
 
     %% verify that the socket:recv length parameter takes
     %% precedence over the default
     ok = check_receive(Socket, Packet, 15, <<"012345678901234">>),
-
-    %% read the remaining 15 bytes
-    _ = socket:recv(Socket, 20),
+    ok = check_receive(Socket, Packet, 15, <<"012345678901234">>),
 
     ok = close_client_socket(Socket),