From bb76da03ea373a694c5818ab4e75246b36f8706e Mon Sep 17 00:00:00 2001
From: Holger Weiss <holger@zedat.fu-berlin.de>
Date: Sat, 16 Jun 2018 00:43:22 +0200
Subject: [PATCH] mod_mam: Don't replace existing stanza ID

Preserve the original stanza ID for resent messages.  This avoids
storing duplicates in the MAM archive.
---
 src/mod_mam.erl | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/mod_mam.erl b/src/mod_mam.erl
index d971983ab..9595be99f 100644
--- a/src/mod_mam.erl
+++ b/src/mod_mam.erl
@@ -404,6 +404,8 @@ get_stanza_id(#message{meta = #{stanza_id := ID}}) ->
     ID.
 
 -spec init_stanza_id(stanza(), binary()) -> stanza().
+init_stanza_id(#message{meta = #{stanza_id := _ID}} = Pkt, _LServer) ->
+    Pkt;
 init_stanza_id(Pkt, LServer) ->
     ID = p1_time_compat:system_time(micro_seconds),
     Pkt1 = strip_my_stanza_id(Pkt, LServer),