Paper/nms-patches/TileEntityJukeBox.patch

--- a/net/minecraft/server/TileEntityJukeBox.java
+++ b/net/minecraft/server/TileEntityJukeBox.java
@@ -31,6 +31,11 @@
     }
 
     public void setRecord(ItemStack itemstack) {
+        // CraftBukkit start - There can only be one
+        if (!itemstack.isEmpty()) {
+            itemstack.setCount(1);
+        }
+        // CraftBukkit end
         this.a = itemstack;
         this.update();
     }