[Arrows] More fixes and assurances for drag arrows (#7117)

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

cockatrice/src/game/game_event_handler.cpp

@@ -229,7 +229,11 @@ void GameEventHandler::handleArrowDeletion(int creatorId, int arrowId)
 
 void GameEventHandler::handleArrowDeletionFinished(const Response &response, int creatorId, int arrowId)
 {
-    if (response.response_code() == Response::RespNameNotFound) {
+    // The server confirms the arrow no longer exists whether it deleted it itself
+    // (RespOk, followed by an Event_DeleteArrow broadcast) or never had it
+    // (RespNameNotFound). In both cases the local copy has to go. deleteArrow is
+    // a no-op if the arrow was already removed by the event broadcast.
+    if (response.response_code() == Response::RespOk || response.response_code() == Response::RespNameNotFound) {
         emit arrowDeleted(creatorId, arrowId);
     }
 }

cockatrice/src/game_graphics/board/arrow_item.cpp

@@ -75,6 +75,14 @@ ArrowItem::~ArrowItem()
 
 void ArrowItem::onTargetDestroyed()
 {
+    if (data->id == -1) {
+        // Drag and attach arrows are never inserted into the arrow registry and
+        // have no server-side counterpart, so no deletion event can clean them
+        // up. Delete them locally when either endpoint is destroyed.
+        delArrow();
+        return;
+    }
+
     emit requestDeletion(data->creatorId, data->id);
 }
 
@@ -384,6 +392,12 @@ void ArrowDragItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
 void ArrowDragItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
 {
     if (!startItem) {
+        // The source card was destroyed while the arrow was being drawn.
+        // Clean up the arrow and its children instead of leaking them.
+        delArrow();
+        for (auto *child : childArrows) {
+            child->mouseReleaseEvent(event);
+        }
         return;
     }
 
@@ -507,6 +521,12 @@ void ArrowAttachItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
 void ArrowAttachItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
 {
     if (!startItem) {
+        // The source card was destroyed while the arrow was being drawn.
+        // Clean up the arrow and its children instead of leaking them.
+        delArrow();
+        for (auto *child : childArrows) {
+            child->mouseReleaseEvent(event);
+        }
         return;
     }