From 7219f42ad2e79a2069c112d4f33a6f54cdfc4cfc Mon Sep 17 00:00:00 2001
From: Daniel Gultsch <daniel@gultsch.de>
Date: Wed, 5 Dec 2018 19:11:40 +0100
Subject: [PATCH] check mam preference for mam:2 namespace and purge offline
 only if set

---
 .../services/XmppConnectionService.java       |  2 +-
 .../conversations/xmpp/XmppConnection.java    | 19 +++++++++++++++++--
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
index d53be0dd7..dad6c558f 100644
--- a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
+++ b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
@@ -307,7 +307,7 @@ public class XmppConnectionService extends Service {
             }
             final boolean flexible = account.getXmppConnection().getFeatures().flexibleOfflineMessageRetrieval();
             final boolean catchup = getMessageArchiveService().inCatchup(account);
-            if (flexible && catchup) {
+            if (flexible && catchup && account.getXmppConnection().isMamPreferenceAlways()) {
                 sendIqPacket(account, mIqGenerator.purgeOfflineMessages(), (acc, packet) -> {
                     if (packet.getType() == IqPacket.TYPE.RESULT) {
                         Log.d(Config.LOGTAG, acc.getJid().asBareJid() + ": successfully purged offline messages");
diff --git a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
index 19d0283de..94833a3b3 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
@@ -47,7 +47,6 @@ import java.util.regex.Matcher;
 
 import javax.net.ssl.KeyManager;
 import javax.net.ssl.SSLContext;
-import javax.net.ssl.SSLSession;
 import javax.net.ssl.SSLSocket;
 import javax.net.ssl.SSLSocketFactory;
 import javax.net.ssl.X509KeyManager;
@@ -75,7 +74,6 @@ import eu.siacs.conversations.services.MessageArchiveService;
 import eu.siacs.conversations.services.NotificationService;
 import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.utils.CryptoHelper;
-import eu.siacs.conversations.utils.IP;
 import eu.siacs.conversations.utils.Patterns;
 import eu.siacs.conversations.utils.Resolver;
 import eu.siacs.conversations.utils.SSLSocketHelper;
@@ -157,6 +155,7 @@ public class XmppConnection implements Runnable {
     private long lastConnect = 0;
     private long lastSessionStarted = 0;
     private long lastDiscoStarted = 0;
+    private boolean isMamPreferenceAlways = false;
     private AtomicInteger mPendingServiceDiscoveries = new AtomicInteger(0);
     private AtomicBoolean mWaitForDisco = new AtomicBoolean(true);
     private AtomicBoolean mWaitingForSmCatchup = new AtomicBoolean(false);
@@ -1170,6 +1169,7 @@ public class XmppConnection implements Runnable {
             Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server caps came from cache");
             disco.put(Jid.of(account.getServer()), discoveryResult);
         }
+        discoverMamPreferences();
         sendServiceDiscoveryInfo(account.getJid().asBareJid());
         if (!requestDiscoItemsFirst) {
             sendServiceDiscoveryItems(Jid.of(account.getServer()));
@@ -1213,6 +1213,21 @@ public class XmppConnection implements Runnable {
         });
     }
 
+    private void discoverMamPreferences() {
+        IqPacket request = new IqPacket(IqPacket.TYPE.GET);
+        request.addChild("prefs", MessageArchiveService.Version.MAM_2.namespace);
+        sendIqPacket(request, (account, response) -> {
+           if (response.getType() == IqPacket.TYPE.RESULT) {
+               Element prefs = response.findChild("prefs", MessageArchiveService.Version.MAM_2.namespace);
+               isMamPreferenceAlways = "always".equals(prefs == null ? null : prefs.getAttribute("default"));
+           }
+        });
+    }
+
+    public boolean isMamPreferenceAlways() {
+        return isMamPreferenceAlways;
+    }
+
     private void finalizeBind() {
         Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": online with resource " + account.getResource());
         if (bindListener != null) {