Wire.fillet with line+circle results in incorrect fillet direction

[sAlexander]

When adding a fillet to a (line + circle) connected edge, the fillet occasionally goes the wrong direction, resulting in a very awkward sharp angle.

The following code reproduces on cadquery-2.5.2 and cadquery-ocp-7.7.2:

def clearPendingWires(workplane):
    workplane.ctx.pendingWires = []
    return workplane

(
    cq.Workplane("XY")
    # Create the 2d shape.
    .lineTo(1, 0)
    .threePointArc((2, 0.75), (3.0, 0))
    .lineTo(4, 0)
    .lineTo(4, 2)
    .threePointArc((2, 3), (0, 2))
    .close()
    .export("before_fillet.dxf")
    .invoke(clearPendingWires)
    # Perform a 2d fillet. This is where the issue occurs.
    .map(lambda w: w.fillet(0.25))
    .export("after_fillet.dxf")
)

before_fillet.dxf:

after_fillet.dxf:

[lorenzncode]

You might try Sketch as a workaround.

from cadquery import Sketch

sk1 = (
    Sketch()
    .segment((0, 0), (1, 0))
    .arc((2, 0.75), (3, 0))
    .segment((4, 0))
    .segment((4, 2))
    .arc((2, 3), (0, 2))
    .close()
    .assemble()
)

sk1 = sk1.vertices().fillet(0.25)

# if you want only the wire from the sketch:
sk1.reset()  # reset selection before selecting the wire
wire1 = sk1.wires().val()

or reusing the original Workplane code:

from cadquery import cq
from cadquery.func import face

wire1 = (
    cq.Workplane("XY")
    # Create the 2d shape.
    .lineTo(1, 0)
    .threePointArc((2, 0.75), (3.0, 0))
    .lineTo(4, 0)
    .lineTo(4, 2)
    .threePointArc((2, 3), (0, 2))
    .close()
    .consolidateWires()
    .val()
)

face1 = face(wire1)
face1 = face1.fillet2D(0.25, face1.vertices())

# to select the wire from the face
wire2 = face1.wires()

In both cases fillet applied to the face is working as expected.