Carefully validate options list

diff --git a/src/gen_mod.erl b/src/gen_mod.erl
index 0b7820fc6c54df400e8aa57e97d5c56fa108e93b..1e069be7323b2abbe26e1ad021958d25cc18bcb8 100644 (file)
--- a/src/gen_mod.erl
+++ b/src/gen_mod.erl
@@ -654,11 +654,10 @@ merge_opts(Opts, DefaultOpts, Module) ->
                      {_, Val} ->
                          case Default of
                              [{A, _}|_] when is_atom(A) andalso is_list(Val) ->
-                                 VFun = opt_type(modules),
-                                 try VFun(Val) of
-                                     NewVal ->
-                                         [{Opt, merge_opts(NewVal, Default, Module)}|Acc]
-                                 catch _:_ ->
+                                 case is_opt_list(Val) of
+                                     true ->
+                                         [{Opt, merge_opts(Val, Default, Module)}|Acc];
+                                     false ->
                                          ?ERROR_MSG(
                                             "Ignoring invalid value '~p' for "
                                             "option '~s' of module '~s'",
@@ -883,12 +882,24 @@ is_equal_opt(Opt, NewOpts, OldOpts) ->
            true
     end.
 
+-spec is_opt_list(term()) -> boolean().
+is_opt_list([]) ->
+    true;
+is_opt_list(L) when is_list(L) ->
+    lists:all(
+      fun({Opt, _Val}) -> is_atom(Opt);
+        (_) -> false
+      end, L);
+is_opt_list(_) ->
+    false.
+
 -spec opt_type(modules) -> fun(([{atom(), list()}]) -> [{atom(), list()}]);
              (atom()) -> [atom()].
 opt_type(modules) ->
     fun(Mods) ->
            lists:map(
-             fun({M, A}) when is_atom(M), is_list(A) ->
+             fun({M, A}) when is_atom(M) ->
+                     true = is_opt_list(A),
                      {M, A}
              end, Mods)
     end;