The bug

A written book is still rendering the hoverEvents and clickEvents of the 15th line of a page, eventhough the text of such line is not visible.

How to reproduce

1. Place a command block to bypass chat length limitation
2. Copy and paste this command into it (don't worry about the multi-line formatting):

   /give @p minecraft:written_book{title:"Doesn't Matter",author:"Doesn't matter either",pages:['[
   	"1\\n",
   	"2\\n",
   	"3\\n",
   	"4\\n",
   	"5\\n",
   	"6\\n",
   	"7\\n",
   	"8\\n",
   	"9\\n",
   	"10\\n",
   	"11\\n",
   	"12\\n",
   	"13\\n",
   	"14\\n",
   	{
   		"text":"15",
   		"hoverEvent":{
   			"action":"show_text","contents":"Can you see this?"
   		},
   		"clickEvent":{
   			"action":"run_command","value":"/tellraw @p \\"you clicked!\\""
   		}
   	}
   ]']}
   

3. Activate the command block (e.g. redstone block)
4. Open the book and hover over the blank area below the printed "14"
   Notice the hover and click of the invisible "15" still work

Expected behaviour

If only 14 lines are supported, the 15th line would not render any text nor allow any events to occur

Actual behaviour

Any additional lines beyond 14 can still run events.