Should a sprint planning meeting be held before the previous sprint has ended?

I am currently working in a team where we are doing the planning aprox halfway through the previous sprint. We start a 2 week sprint on a Monday, and the following Tuesday (1 week later) we have a planning meeting for the following sprint to start in a weeks time. We also conduct a weekly backlog grooming meeting where we prepare stories for planning.

Is this normal? My scrum master says this is a common method and widely used.
Is there any source of information for the case of holding the planning during the previous sprint?
Does anyone have an opinion on the pros/cons of doing this?

I agree that it seems unusual, but I need some good reasons for doing it. I can't bring this up only knowing the negatives. Is there any justification for doing the planning before the end of a sprint?

Solution

Is this normal? My scrum master says this is a common method and widely used.

No. He is incorrect. One sprint ends with a sprint review meeting. Then, the next sprint begins with a sprint planning meeting. Another meeting that happens during a sprint is a Product Backlog Refinement (aka Grooming) meeting.

Is there any source of information for the case of holding the planning during the previous sprint?

There appears to be no source of such information, other than your Scrum Master.

Does anyone have an opinion on the pros/cons of doing this?

Yes. It wastes time for at least two reasons:

It takes up time, during the sprint, when other work (such as perhaps backlog refinement) could be done.
The planning that is accomplished in that meeting may need to be re-planned at the beginning of the next sprint.

...I need some pros, some good reasons for doing it. I can't bring this up only knowing the negatives.

Really, there are only negatives.