how to connect walls?

[jms3000]

When I draw walls in a square (for example a chimney), the walls are connected in a spacial 45° manner.
But at the end when I close the square, I'm not possible to get this 45° conenction. How do I make it?

[Puybaret]

As written in the help about wall creation:

While drawing a set of walls, the start point of the first wall will be attached to an existing wall start or end point if you click on that point, and the last wall will be attached to another wall start or end point by double-clicking on that point.