Fix endless loop adding and removing omemo devices

When removing an old omemo device not seen for longer than 90 days, that
device might still be active (just not sending messages) and immediately
add itself back into the devicelist. This will cause a bundle fetch.
We don't want to delete the device again for not being known if the bundle
fetch is still pending. Similarly for session repairs and queued key
transport messages.

Author: tmolitor-stud-tu

Monal/Classes/MLOMEMO.m

@@ -286,6 +286,8 @@ -(void) repairQueuedSessions
     [self checkBundleFetchCount];
 
     DDLogVerbose(@"New state: %@", self.state);
+    
+    [self cleanupOwnOldDevices];
 }
 
 -(void) retriggerKeyTransportElementsForJid:(NSString*) jid
@@ -308,6 +310,8 @@ -(void) retriggerKeyTransportElementsForJid:(NSString*) jid
         [self.state.queuedKeyTransportElements removeObjectForKey:jid];
         [self sendKeyTransportElement:jid forRids:rids];
     }
+    
+    [self cleanupOwnOldDevices];
 }
 
 $$instance_handler(devicelistHandler, account.omemo, $$ID(xmpp*, account), $$ID(NSString*, node), $$ID(NSString*, jid), $$ID(NSString*, type), $_ID((NSDictionary<NSString*, MLXMLNode*>*), data))
@@ -562,8 +566,30 @@ -(void) handleOwnDevicelistUpdate:(NSSet<NSNumber*>*) receivedDevices
 
 -(void) cleanupOwnOldDevices
 {
-    NSMutableArray* deletedDevices = [NSMutableArray new];
     NSString* jid = self.account.connectionProperties.identity.jid;
+    
+    //don't try to clean up in all these cases
+    @synchronized(self.state.queuedKeyTransportElements) {
+        if(self.state.queuedKeyTransportElements[jid] != nil && [self.state.queuedKeyTransportElements[jid] count] > 0)
+        {
+            DDLogWarn(@"Not cleaning up own old devices: key transport elements still queued!");
+            return
+        }
+    }
+    @synchronized(self.state.queuedSessionRepairs) {
+        if(self.state.queuedSessionRepairs[jid] != nil && [self.state.queuedSessionRepairs[jid] count] > 0)
+        {
+            DDLogWarn(@"Not cleaning up own old devices: session repairs still queued!");
+            return
+        }
+    }
+    if(self.state.openBundleFetches[jid] != nil && self.state.openBundleFetches[jid].count > 0)
+    {
+        DDLogWarn(@"Not cleaning up own old devices: bundle fetches still pending!");
+        return
+    }
+    
+    NSMutableArray* deletedDevices = [NSMutableArray new];
     for(NSNumber* device in [self.ownDeviceList copy])
     {
         SignalAddress* address = [[SignalAddress alloc] initWithName:jid deviceId:(uint32_t)device.unsignedIntValue];