Disable opaque_union Dialyzer warnings introduced in Erlang/OTP 28

See
erlang/otp@5dab31e

mix.exs

@@ -113,7 +113,7 @@ defmodule Ejabberd.MixProject do
              if_version_below(~c"25", [{:d, :OTP_BELOW_25}]) ++
              if_version_below(~c"26", [{:d, :OTP_BELOW_26}]) ++
              if_version_below(~c"27", [{:d, :OTP_BELOW_27}]) ++
-             if_type_exported(:odbc, {:opaque, :connection_reference, 0}, [{:d, :ODBC_HAS_TYPES}])
+             if_version_below(~c"28", [{:d, :OTP_BELOW_28}])
     defines = for {:d, value} <- result, do: {:d, value}
     result ++ [{:d, :ALL_DEFS, defines}]
   end

rebar.config

@@ -140,14 +140,14 @@
             {if_version_below, "25", {d, 'OTP_BELOW_25'}},
             {if_version_below, "26", {d, 'OTP_BELOW_26'}},
             {if_version_below, "27", {d, 'OTP_BELOW_27'}},
+            {if_version_below, "28", {d, 'OTP_BELOW_28'}},
             {if_var_false, debug, no_debug_info},
             {if_var_true, debug, debug_info},
             {if_var_true, elixir, {d, 'ELIXIR_ENABLED'}},
             {if_var_true, new_sql_schema, {d, 'NEW_SQL_SCHEMA'}},
             {if_var_true, roster_gateway_workaround, {d, 'ROSTER_GATEWAY_WORKAROUND'}},
             {if_var_true, sip, {d, 'SIP'}},
             {if_var_true, stun, {d, 'STUN'}},
-            {if_type_exported, {odbc, {opaque, connection_reference, 0}}, {d, 'ODBC_HAS_TYPES'}},
             {src_dirs, [src,
                         {if_rebar3, sql},
                         {if_var_true, tools, tools}]}]}.

src/ejabberd_config.erl

@@ -68,6 +68,10 @@
 
 -optional_callbacks([globals/0]).
 
+-ifndef(OTP_BELOW_28).
+-dialyzer([no_opaque_union]).
+-endif.
+
 %%%===================================================================
 %%% API
 %%%===================================================================

src/ejabberd_shaper.erl

@@ -36,6 +36,10 @@
 
 -export_type([shaper/0, shaper_rule/0, shaper_rate/0]).
 
+-ifndef(OTP_BELOW_28).
+-dialyzer([no_opaque_union]).
+-endif.
+
 %%%===================================================================
 %%% API
 %%%===================================================================

src/ejabberd_sql.erl

@@ -70,18 +70,29 @@
 -export([connecting/2, connecting/3,
 	 session_established/2, session_established/3]).
 
--ifdef(ODBC_HAS_TYPES).
-    -type(odbc_connection_reference() ::  odbc:connection_reference()).
+-ifdef(OTP_BELOW_28).
+-ifdef(OTP_BELOW_27).
+%% OTP 26 or lower
+-type(odbc_connection_reference() ::  odbc:connection_reference()).
+-type(db_ref_pid() :: pid()).
 -else.
-    -type(odbc_connection_reference() ::  pid()).
+%% OTP 27
+-type(odbc_connection_reference() :: pid()).
+-type(db_ref_pid() :: pid()).
+-endif.
+-else.
+%% OTP 28 or higher
+-nominal(odbc_connection_reference() :: odbc:connection_reference()).
+-nominal(db_ref_pid() :: pid()).
+-dialyzer([no_opaque_union]).
 -endif.
 
 -include("logger.hrl").
 -include("ejabberd_sql_pt.hrl").
 -include("ejabberd_stacktrace.hrl").
 
 -record(state,
-	{db_ref               :: undefined | pid() | odbc_connection_reference(),
+	{db_ref               :: undefined | db_ref_pid() | odbc_connection_reference(),
 	 db_type = odbc       :: pgsql | mysql | sqlite | odbc | mssql,
 	 db_version           :: undefined | non_neg_integer() | {non_neg_integer(), atom(), non_neg_integer()},
 	 reconnect_count = 0  :: non_neg_integer(),

src/ejabberd_websocket.erl

@@ -62,6 +62,11 @@
                           ?AC_ALLOW_HEADERS, ?AC_MAX_AGE]).
 -define(HEADER, [?CT_XML, ?AC_ALLOW_ORIGIN, ?AC_ALLOW_HEADERS]).
 
+-ifndef(OTP_BELOW_28).
+-dialyzer([no_opaque_union]).
+-endif.
+
+
 is_valid_websocket_upgrade(_Path, Headers) ->
     HeadersToValidate = [{'Upgrade', <<"websocket">>},
                          {'Connection', ignore},

src/mod_muc_room.erl

@@ -116,6 +116,10 @@
 -callback search_affiliation(binary(), binary(), binary(), affiliation()) ->
     {ok, [{ljid(), {affiliation(), binary()}}]} | {error, any()}.
 
+-ifndef(OTP_BELOW_28).
+-dialyzer([no_opaque_union]).
+-endif.
+
 %%%----------------------------------------------------------------------
 %%% API
 %%%----------------------------------------------------------------------