avoid error message on small contour fill with single or double spiral (#2403)

2 files changed, 6 insertions, 2 deletions

diff --git a/lib/stitches/contour_fill.py b/lib/stitches/contour_fill.py
index 2ea61afb..993fa104 100644
--- a/lib/stitches/contour_fill.py
+++ b/lib/stitches/contour_fill.py
@@ -569,6 +569,7 @@ def _make_fermat_spiral(rings, stitch_length, starting_point):
 
 def _make_spiral(rings, stitch_length, starting_point):
     path = []
+    spiral_part = None
 
     for ring1, ring2 in zip(rings[:-1], rings[1:]):
         check_stop_flag()
@@ -577,7 +578,8 @@ def _make_spiral(rings, stitch_length, starting_point):
         # skip last to avoid duplicated points
         path.extend(spiral_part.coords[:-1])
 
-    # at the end add last point
-    path.append(spiral_part.coords[-1])
+    if spiral_part:
+        # at the end add last point
+        path.append(spiral_part.coords[-1])
 
     return path
diff --git a/lib/stitches/running_stitch.py b/lib/stitches/running_stitch.py
index 29e2547d..b6262a45 100644
--- a/lib/stitches/running_stitch.py
+++ b/lib/stitches/running_stitch.py
@@ -249,6 +249,8 @@ def path_to_curves(points: typing.List[Point], min_len: float):
 
 def running_stitch(points, stitch_length, tolerance):
     # Turn a continuous path into a running stitch.
+    if not points:
+        return
     stitches = [points[0]]
     for curve in path_to_curves(points, 2 * tolerance):
         # segments longer than twice the tollerance will usually be forced by it, so set that as the minimum for corner detection