Fix dialyzer warnings for mod_mam

include/mod_mam.hrl

@@ -4,7 +4,7 @@
 	 timestamp = p1_time_compat:timestamp() :: erlang:timestamp() | '_' | '$1',
 	 peer = {<<"">>, <<"">>, <<"">>}      :: ljid() | '_' | '$3' | undefined,
 	 bare_peer = {<<"">>, <<"">>, <<"">>} :: ljid() | '_' | '$3',
-	 packet = #xmlel{}                    :: xmlel() | '_',
+	 packet = #xmlel{}                    :: xmlel() | message() | '_',
 	 nick = <<"">>                        :: binary(),
 	 type = chat                          :: chat | groupchat}).
 

src/mod_mam.erl

@@ -945,7 +945,7 @@ filter_by_max(Msgs, Len) when is_integer(Len), Len >= 0 ->
 filter_by_max(_Msgs, _Junk) ->
     {[], true}.
 
--spec limit_max(rsm_set(), binary()) -> rsm_set().
+-spec limit_max(rsm_set(), binary()) -> rsm_set() | undefined.
 limit_max(RSM, ?NS_MAM_TMP) ->
     RSM; % XEP-0313 v0.2 doesn't require clients to support RSM.
 limit_max(#rsm_set{max = Max} = RSM, _NS) when not is_integer(Max) ->

src/mod_mam_sql.erl

@@ -217,13 +217,10 @@ make_sql_query(User, LServer,
 		     true ->
 			  []
 		  end,
-    WithTextClause = case WithText of
-			 {text, <<>>} ->
-			     [];
-			 {text, Txt} ->
+    WithTextClause = if is_binary(WithText), WithText /= <<>> ->
 			     [<<" and match (txt) against ('">>,
-			      Escape(Txt), <<"')">>];
-			 undefined ->
+			      Escape(WithText), <<"')">>];
+			true ->
 			     []
 		     end,
     WithClause = case catch jid:tolower(With) of