From 17cf84f68b652873325ab9f6dd9ce296d757e809 Mon Sep 17 00:00:00 2001
From: jdegenstein <jdegenstein@users.noreply.github.com>
Date: Tue, 23 Jan 2024 10:06:25 -0600
Subject: [PATCH 1/4] operations_generic.py -> try offset with inner wires,
 silently drop otherwise

---
 src/build123d/operations_generic.py | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/build123d/operations_generic.py b/src/build123d/operations_generic.py
index 5d00e218..057a3b2e 100644
--- a/src/build123d/operations_generic.py
+++ b/src/build123d/operations_generic.py
@@ -593,11 +593,12 @@ def offset(
             outer_wire = outer_wire.fix_degenerate_edges(min_edge_length)
         inner_wires = []
         for inner_wire in face.inner_wires():
-            offset_wire = inner_wire.offset_2d(-amount, kind=kind)
-            if min_edge_length is not None:
-                inner_wires.append(offset_wire.fix_degenerate_edges(min_edge_length))
-            else:
-                inner_wires.append(offset_wire)
+            try:
+                offset_wire = inner_wire.offset_2d(-amount, kind=kind)
+                if min_edge_length is not None:
+                    inner_wires.append(offset_wire.fix_degenerate_edges(min_edge_length))
+                else:
+                    inner_wires.append(offset_wire)
         new_faces.append(Face.make_from_wires(outer_wire, inner_wires))
     if edges:
         if len(edges) == 1 and edges[0].geom_type() == "LINE":

From 8372c3f7b6b42ba52dbfeefea33a464037bf3d36 Mon Sep 17 00:00:00 2001
From: jdegenstein <jdegenstein@users.noreply.github.com>
Date: Tue, 23 Jan 2024 10:08:55 -0600
Subject: [PATCH 2/4] operations_generic.py -> except pass

---
 src/build123d/operations_generic.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/build123d/operations_generic.py b/src/build123d/operations_generic.py
index 057a3b2e..3e58431c 100644
--- a/src/build123d/operations_generic.py
+++ b/src/build123d/operations_generic.py
@@ -599,6 +599,8 @@ def offset(
                     inner_wires.append(offset_wire.fix_degenerate_edges(min_edge_length))
                 else:
                     inner_wires.append(offset_wire)
+            except:
+                pass
         new_faces.append(Face.make_from_wires(outer_wire, inner_wires))
     if edges:
         if len(edges) == 1 and edges[0].geom_type() == "LINE":

From 9919882e790f965914bb60374f03b944d2d9d58f Mon Sep 17 00:00:00 2001
From: jdegenstein <jdegenstein@users.noreply.github.com>
Date: Tue, 23 Jan 2024 10:29:34 -0600
Subject: [PATCH 3/4] test_build_generic.py -> add offset test with inner wire
 that gets removed

---
 tests/test_build_generic.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tests/test_build_generic.py b/tests/test_build_generic.py
index 9c8d5bc4..77c7fe89 100644
--- a/tests/test_build_generic.py
+++ b/tests/test_build_generic.py
@@ -591,6 +591,14 @@ def test_offset_algebra_wire(self):
         o_line = offset(line, amount=3.177)
         self.assertEqual(len(o_line.edges()), 19)
 
+    def test_offset_face_with_inner_wire(self):
+        # offset amount causes the inner wire to have zero area
+        b = Rectangle(1, 1)
+        b -= RegularPolygon(.25, 3)
+        b = offset(b, amount=0.125)
+        self.assertAlmostEqual(b.area, 1 ** 2 + 2 * 0.125 * 2 + pi * 0.125 ** 2, 5)
+        self.assertEqual(len(b.face().inner_wires()), 0)
+    
     def test_offset_bad_type(self):
         with self.assertRaises(TypeError):
             offset(Vertex(), amount=1)

From 911e120b24fdc838582d70f7a7b67260b018177c Mon Sep 17 00:00:00 2001
From: jdegenstein <jdegenstein@users.noreply.github.com>
Date: Tue, 23 Jan 2024 10:48:48 -0600
Subject: [PATCH 4/4] test_build_generic.py -> add min_edge_length tests for
 offset

---
 tests/test_build_generic.py | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/tests/test_build_generic.py b/tests/test_build_generic.py
index 77c7fe89..95155557 100644
--- a/tests/test_build_generic.py
+++ b/tests/test_build_generic.py
@@ -592,12 +592,25 @@ def test_offset_algebra_wire(self):
         self.assertEqual(len(o_line.edges()), 19)
 
     def test_offset_face_with_inner_wire(self):
-        # offset amount causes the inner wire to have zero area
+        # offset amount causes the inner wire to have zero length
         b = Rectangle(1, 1)
         b -= RegularPolygon(.25, 3)
         b = offset(b, amount=0.125)
         self.assertAlmostEqual(b.area, 1 ** 2 + 2 * 0.125 * 2 + pi * 0.125 ** 2, 5)
         self.assertEqual(len(b.face().inner_wires()), 0)
+
+    def test_offset_face_with_min_length(self):
+        c = Circle(.5)
+        c = offset(c, amount=0.125, min_edge_length=0.1)
+        self.assertAlmostEqual(c.area, pi * (0.5 + 0.125) ** 2, 5)
+    
+    def test_offset_face_with_min_length_and_inner(self):
+        # offset amount causes the inner wire to have zero length
+        c = Circle(.5)
+        c -= RegularPolygon(.25, 3)
+        c = offset(c, amount=0.125, min_edge_length=0.1)
+        self.assertAlmostEqual(c.area, pi * (0.5 + 0.125) ** 2, 5)
+        self.assertEqual(len(c.face().inner_wires()), 0)
     
     def test_offset_bad_type(self):
         with self.assertRaises(TypeError):