When a fishing rod is cast into water and something is caught, right-clicking the rod has no response (nothing is reeled in, and no item is generated). The bob continues to float in the water.
To reproduce:
Cast an unenchanted fishing rod into an open body of water (a swamp and mountain lake were tested in my case).
Wait for something to be 'hooked'.
Attempt to reel the rod in, like normal (it should not work, and should continue floating as if it wasn't reeled at all).
It is possible to reel the rod in before and after the animation/catching event, but not during.
Edit: Sorry for the duplicate, I see now it's been posted before.
Your question is a duplicate of MC-181424.