0.84b1: Draw tool: When selecting layers are ignored

[helmut]

When selecting shapes that have been drawn before, the layering is ignored:

To reproduce:
1. Draw a large rectangle
2. Draw two lines that start and end within the rectangle.
3. Try to select the two lines.
--> Instead of the two lines always the rectangle is selected. I.e. the layering of the shapes is ignored.

[helmut]

0.84 b2: Fixed.