When you use a fishing rod and it's damaged, you can craft a carrot on a stick/warped fungus on a stick that's full durability. When they break, instead of disappearing they become a fishing rod, but it's on full durability, which means you can repair a fishing rod without mending, anvils etc
Linked issues
Comments 3
Can confirm for 1.16.3rc1+

Thank you for your report!
We're tracking this issue as MC-123196, so this ticket is being resolved and linked as a duplicate.
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I can confirm