Avoids concurrent exceptions

app/src/main/java/com/vitorpamplona/amethyst/model/Account.kt

@@ -373,13 +373,13 @@ class Account(
 
   fun isAcceptable(user: User): Boolean {
     return user !in hiddenUsers()  // if user hasn't hided this author
-        && user.reports.firstOrNull { it.author == userProfile() } == null // if user has not reported this post
-        && user.reports.filter { it.author in userProfile().follows }.size < 5
+        && user.reportsBy( userProfile() ).isEmpty() // if user has not reported this post
+        && user.reportsBy( userProfile().follows ).size < 5
   }
 
   fun isAcceptableDirect(note: Note): Boolean {
-    return note.reports.firstOrNull { it.author == userProfile() } == null // if user has not reported this post
-        && note.reports.filter { it.author in userProfile().follows }.size < 5 // if it has 5 reports by reliable users
+    return note.reportsBy( userProfile() ).isEmpty()  // if user has not reported this post
+        && note.reportsBy( userProfile().follows ).size < 5 // if it has 5 reports by reliable users
   }
 
   fun isAcceptable(note: Note): Boolean {

app/src/main/java/com/vitorpamplona/amethyst/model/Note.kt

@@ -107,6 +107,18 @@ class Note(val idHex: String) {
         }
     }
 
+    fun reportsBy(user: User): List<Note> {
+        return synchronized(reports) {
+            reports.filter { it.author == user }
+        }
+    }
+
+    fun reportsBy(users: Set<User>): List<Note> {
+        return synchronized(reports) {
+            reports.filter { it.author in users }
+        }
+    }
+
     // Observers line up here.
     val live: NoteLiveData = NoteLiveData(this)
 

app/src/main/java/com/vitorpamplona/amethyst/model/User.kt

@@ -93,6 +93,18 @@ class User(val pubkey: ByteArray) {
         }
     }
 
+    fun reportsBy(user: User): List<Note> {
+        return synchronized(reports) {
+            reports.filter { it.author == user }
+        }
+    }
+
+    fun reportsBy(users: Set<User>): List<Note> {
+        return synchronized(reports) {
+            reports.filter { it.author in users }
+        }
+    }
+
     @Synchronized
     fun getOrCreateChannel(user: User): MutableSet<Note> {
         return messages[user] ?: run {