Warning when a copy and paste deviates from normal

Hi Guys,
I have a simple feature request due to some repeating accidents;
sometimes, when doing copy and paste, I wrongly mark the whole column before hitting Ctrl+v
This generates an overload in LO and make LO freeze for 10 minutes+
Undoing it takes another 10 minutes+
This on pretty normal PC; a Lenovo i5-4300M, 8GB RAM.

I suggest that you make an “are you sure”-warning before staring such heavy operations.

I know I’m able to shutdown LO and restart the process, but that’s not always ideal, due the possible loss of unsaved work.