From: Holger Weiss <holger@zedat.fu-berlin.de>
Date: Thu, 21 Feb 2019 21:19:29 +0000 (+0100)
Subject: mod_mam_mnesia: Fix check for empty archive
X-Git-Tag: 19.02~22
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9a3a7369cb797d722e856553755c12be54a89d5d;p=ejabberd

mod_mam_mnesia: Fix check for empty archive

Don't return 'true' if the key exists but points to an empty archive.
Also, avoid looking up all keys.
---

diff --git a/src/mod_mam_mnesia.erl b/src/mod_mam_mnesia.erl
index f94dd2e49..dff10ef96 100644
--- a/src/mod_mam_mnesia.erl
+++ b/src/mod_mam_mnesia.erl
@@ -200,8 +200,7 @@ select(_LServer, JidRequestor,
     Result.
 
 is_empty_for_user(LUser, LServer) ->
-	not lists:member({LUser, LServer},
-		mnesia:dirty_all_keys(archive_msg)).
+    mnesia:dirty_read(archive_msg, {LUser, LServer}) == [].
 
 is_empty_for_room(_LServer, LName, LHost) ->
     is_empty_for_user(LName, LHost).