In my opinion i would have replaced the whole faucet.
Tub spout copper pipe too long.
Total the two and add 1 4 inch.
You need to un screw the spout and the pipe nipple.
For slip on tub spouts your copper pipe should be a minimum 1 and a maximum 2 7 8 in length depending on the tub spout.
That means with the tile you can no longer reach the threads in the spout.
If you d like to support the channel you can do so by shopping for tools or whatever you need on amazon through this link https amzn to 2dc7pxk if i ve p.
Refer to the manufacturer s specifications prior to purchasing and installing to ensure you have the appropriate length for your spout.
Replace with a shorter nipple equal to the gap measurement.
Smsplumbing md the pipe looks to be soldered but your spout is still on so its hard to see the side that is in the spout.
I made a big mistake by cutting the 1 2 copper nub coming out of the wall to less than the minimum called for.
Solder on a new adapter.
Use teflon tape on all male pipe threads and caulking behind the spout base.
Tub spout nipple too long after remodel.
Idreos md i replaced a bath tub spout with a danco spout made to replace the old moen spout.
To use the threaded adapter measure from the shoulder of the existing adapter to the wall.
Now cut another piece of 1 2 copper 1 3 8 long you may now solder the piece in using two couplings or two sharkbite connectors.
You can cut the pipe and solder on another male threaded adapter or you can cut the pipe and use the slip fit adapter.
Well you have a choice.
Measure the length of your tub spout from the back edge of the spout to the front where the threads start on the inside of the spout.
First figure how short you are let s say you re 3 8 shy of making a connection.
Then measure the distance from the surface of the wall to the back of the threaded elbow inside the wall.
If it is copper inside the spout cut the male adapter off and buy the slip on spout.
Reduce that measurement by 1 5 inches and cut the pipe there.
The result is the overall length of the pipe you need.
The faster just as appropriate but may not look that good repair is to apply enough caulking into the gap so that it can be smoothed flush with the spout.