Created attachment 76727 [details]
bug description

When I try to edit a shape made from the calligraphy tool, the shape position goes crazy if I try to move a node on the top or the left side of the object bounding box. This should be fixed to make the calligraphy tool much more useful.

See attached screenshots
-01 is the base shape, with its bounding box quickly traced in red on a bitmap layer,
-02 is moving some nodes on right and bottom sides: works ok,
-03, is trying to move some nodes at the top and the left sides: shape goes crazy in the opposite direction, and only dragging blindly the node back to inside the original bounding box brings back the shape.