From 8b5e6e4a138a8c686cc392c47f866dcaab485f87 Mon Sep 17 00:00:00 2001
From: Alexey Shchepin <alexey@process-one.net>
Date: Mon, 23 Jan 2017 19:04:22 +0300
Subject: [PATCH] Compatibility with R17 in mod_block_strangers

---
 rebar.config                |  1 +
 src/mod_block_strangers.erl | 21 ++++++++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/rebar.config b/rebar.config
index cc04c86d0..7e9fe145e 100644
--- a/rebar.config
+++ b/rebar.config
@@ -88,6 +88,7 @@
             {if_var_true, elixir, {d, 'ELIXIR_ENABLED'}},
             {if_var_true, erlang_deprecated_types, {d, 'ERL_DEPRECATED_TYPES'}},
 	    {if_version_above, "18", {d, 'STRONG_RAND_BYTES'}},
+	    {if_version_above, "17", {d, 'GB_SETS_ITERATOR_FROM'}},
             {if_var_true, hipe, native},
             {src_dirs, [asn1, src,
                         {if_var_true, tools, tools},
diff --git a/src/mod_block_strangers.erl b/src/mod_block_strangers.erl
index 383848724..56fddd093 100644
--- a/src/mod_block_strangers.erl
+++ b/src/mod_block_strangers.erl
@@ -92,11 +92,30 @@ filter_packet(Acc) ->
     Acc.
 
 sets_bare_member({U, S, <<"">>} = LBJID, Set) ->
-    case ?SETS:next(?SETS:iterator_from(LBJID, Set)) of
+    case ?SETS:next(sets_iterator_from(LBJID, Set)) of
         {{U, S, _}, _} -> true;
         _ -> false
     end.
 
+-ifdef(GB_SETS_ITERATOR_FROM).
+sets_iterator_from(Element, Set) ->
+    ?SETS:iterator_from(Element, Set).
+-else.
+%% Copied from gb_sets.erl
+%% TODO: Remove after dropping R17 support
+sets_iterator_from(S, {_, T}) ->
+    iterator_from(S, T, []).
+
+iterator_from(S, {K, _, T}, As) when K < S ->
+    iterator_from(S, T, As);
+iterator_from(_, {_, nil, _} = T, As) ->
+    [T | As];
+iterator_from(S, {_, L, _} = T, As) ->
+    iterator_from(S, L, [T | As]);
+iterator_from(_, nil, As) ->
+    As.
+-endif.
+
 
 depends(_Host, _Opts) ->
     [].
-- 
2.40.0