Harden layer reorder against unintended/partial changes

Author: gwigz

indra/llui/llflatlistview.cpp

@@ -687,7 +687,10 @@ void LLFlatListView::onItemMouseClick(item_pair_t* item_pair, MASK mask)
         setFocus(true);
     }
 
-    armReorderDrag(item_pair);
+    if (!(mask & (MASK_SHIFT | MASK_CONTROL)))
+    {
+        armReorderDrag(item_pair);
+    }
 
     bool select_item = !isSelected(item_pair);
 

indra/newview/llappearancemgr.cpp

@@ -4571,6 +4571,13 @@ bool LLAppearanceMgr::reorderWearableGroup(LLWearableType::EType type, const uui
     if (count < 2) return false;
     if (ordered_link_ids.size() != count) return false; // order must cover the whole group
 
+    // Validate everything before mutating, so a bad link can't leave it half-reordered.
+    for (const LLUUID& link_id : ordered_link_ids)
+    {
+        LLViewerInventoryItem* link = gInventory.getItem(link_id);
+        if (!link || link->getWearableType() != type) return false;
+    }
+
     // ordered_link_ids runs furthest-to-closest; body index 0 is closest to the body.
     // Place each target at its body index, leaving already-placed lower indices untouched.
     for (U32 body_index = 0; body_index < count; ++body_index)