Properly delete conversations with deleted participants

diff --git a/files/lib/data/conversation/ConversationAction.class.php b/files/lib/data/conversation/ConversationAction.class.php
index 5eee0101a333bd7a210e7e77b1aaabe34db00da9..0be848964c399e4b55e916ba34e1386df9417ccb 100644 (file)
--- a/files/lib/data/conversation/ConversationAction.class.php
+++ b/files/lib/data/conversation/ConversationAction.class.php
@@ -591,7 +591,9 @@ class ConversationAction extends AbstractDatabaseObjectAction implements IClipbo
                        $sql = "SELECT          DISTINCT conversation.conversationID
                                FROM            wcf".WCF_N."_conversation conversation
                                LEFT JOIN       wcf".WCF_N."_conversation_to_user conversation_to_user
-                               ON              (conversation_to_user.conversationID = conversation.conversationID AND conversation_to_user.hideConversation <> ".Conversation::STATE_LEFT.")
+                               ON              (       conversation_to_user.conversationID = conversation.conversationID
+                                               AND     conversation_to_user.hideConversation <> ".Conversation::STATE_LEFT."
+                                               AND     conversation_to_user.participantID IS NOT NULL)
                                ".$conditionBuilder;
                        $statement = WCF::getDB()->prepareStatement($sql);
                        $statement->execute($conditionBuilder->getParameters());