I once saw a tutorial on YouTube that gave me a simple keystroke to rotate the end face of a cylinder without deforming the sides. I used it many times, but then didn't require it for a year, until now, when it would be really useful.
Most answers in public forums relate to using the bisect tool instead of rotate, but that was not the solution I came across on YouTube and interrupts workflow.
Does anybody know how to do this? It is extremely useful and precise, as you can simply enter [something] then [r] and then the degree, and it forms a perfect turn in the cylinder without crushing the sides.