handle notifications throttling on backlog finish event

src/main/java/eu/siacs/conversations/services/NotificationService.java

@@ -395,7 +395,23 @@ public class NotificationService {
                     count = getBacklogMessageCount(account);
                 }
 
-                updateNotification(count > 0, conversations);
+                boolean shouldNotify = count > 0;
+
+                if (shouldNotify) {
+                    boolean allConversationsShouldBeThrottled = true;
+                    for (String c : conversations) {
+                        if (!shouldNotificationSoundBeThrottled(c)) {
+                            allConversationsShouldBeThrottled = false;
+                            break;
+                        }
+                    }
+
+                    if (allConversationsShouldBeThrottled) {
+                        shouldNotify = false;
+                    }
+                }
+
+                updateNotification(shouldNotify, conversations);
             }
         }
         synchronized (mMissedCalls) {
@@ -733,7 +749,7 @@ public class NotificationService {
                     (!(this.mIsInForeground && this.mOpenConversation == null) || isScreenLocked)
                             && !account.inGracePeriod()
                             && !this.inMiniGracePeriod(account) &&
-                            !shouldNotificationSoundBeThrottled(conversation);
+                            !shouldNotificationSoundBeThrottled(conversation.getUuid());
 
             updateNotification(doNotify, Collections.singletonList(conversation.getUuid()));
 
@@ -940,8 +956,8 @@ public class NotificationService {
         }
     }
 
-    private boolean shouldNotificationSoundBeThrottled(@Nullable Conversational conversation) {
+    private boolean shouldNotificationSoundBeThrottled(@Nullable String conversationUuid) {
-        if (conversation == null) {
+        if (conversationUuid == null) {
             return false;
         }
 
@@ -951,7 +967,7 @@ public class NotificationService {
             return false;
         }
 
-        long lastNotificationTimestamp = ensureLastNotificationTimeByConversation().getLong(conversation.getUuid(), -1L);
+        long lastNotificationTimestamp = ensureLastNotificationTimeByConversation().getLong(conversationUuid, -1L);
 
         if (lastNotificationTimestamp <= 0L) {
             return false;