Fix an issue when auto_satin produces NoneType satins (#3680)

2 files changed, 9 insertions, 2 deletions

diff --git a/lib/elements/satin_column.py b/lib/elements/satin_column.py
index 16e7b01f..ff5cfe86 100644
--- a/lib/elements/satin_column.py
+++ b/lib/elements/satin_column.py
@@ -1025,9 +1025,9 @@ class SatinColumn(EmbroideryElement):
         """
 
         for path_list in path_lists:
-            num_paths = len(path_list)
             if path_list is None:
                 continue
+            num_paths = len(path_list)
             if num_paths in (2, 4):
                 # Add the rung just after the start of the satin.
                 # If the rails have opposite directions it may end up at the end of the satin.
diff --git a/lib/stitches/auto_satin.py b/lib/stitches/auto_satin.py
index d01ef7b8..22d489db 100644
--- a/lib/stitches/auto_satin.py
+++ b/lib/stitches/auto_satin.py
@@ -87,6 +87,10 @@ class SatinSegment(object):
         if self.end < 1.0:
             satin, after = satin.split(None, cut_points=end)
 
+        # the cut operation can lead to a NoneType element
+        if satin is None:
+            return
+
         if self.reverse:
             satin = satin.reverse()
 
@@ -552,7 +556,10 @@ def operations_to_elements_and_trims(operations, preserve_order):
         # Ignore JumpStitch operations.  Jump stitches in Ink/Stitch are
         # implied and added by Embroider if needed.
         if isinstance(operation, (SatinSegment, RunningStitch)):
-            elements.append(operation.to_element())
+            element = operation.to_element()
+            if not element:
+                continue
+            elements.append(element)
             original_parent_nodes.append(operation.original_node.getparent())
         elif isinstance(operation, (JumpStitch)):
             if elements and operation.should_trim():