SecondMouseAU · gsdali · Sep 7, 2026 · Sep 7, 2026 · Sep 7, 2026 · Sep 7, 2026
diff --git a/CLAUDE.md b/CLAUDE.md
@@ -220,7 +220,6 @@ the reproducer). What a bridge author needs without opening it:
 
 - `BRepExtrema_ExtCC` crashes on parallel edges: `if (result.isParallel) { return result; }`
   before reading points. `Extrema_ExtCC::Points` itself over-reads on the same input (patch `0024`).
-- `LocOpe_SplitDrafts::Perform()` throws on incompatible geometry: always `try`/`catch` it.
 - `OCC_CATCH_SIGNALS` is inert in this build (no `OCC_CONVERT_SIGNALS`). An OS signal raised
   inside OCCT is uncatchable in-process, and so is a C++ exception that reaches the Swift boundary
   (#345), which is why every `gp_Dir`/`gp_Ax*`/`Geom_Direction` construction from caller doubles

diff --git a/README.md b/README.md
@@ -9,7 +9,7 @@
 
 A comprehensive Swift wrapper for [OpenCASCADE Technology (OCCT)](https://www.opencascade.com/) 8.0.1, providing B-Rep solid modeling for macOS and iOS. **v3.0.0. SemVer-stable; see [SEMVER.md](docs/SEMVER.md#v300) before upgrading from v2.x.**
 
-**4,366 wrapped operations** | macOS 12+ / iOS 15+ (arm64), visionOS and tvOS untested | OCCT 8.0.1
+**4,365 wrapped operations** | macOS 12+ / iOS 15+ (arm64), visionOS and tvOS untested | OCCT 8.0.1
 ## Quick Start
 
 ### Installation

diff --git a/Scripts/repro/1393-splitdrafts/README.md b/Scripts/repro/1393-splitdrafts/README.md
@@ -51,7 +51,25 @@ the process**. Through the bridge it is catchable (the Swift call returns `nil`,
 regression test asserts), so this is a difference in where the throw crosses, not in whether it
 happens.
 
-## Disposition
+## Outcome: the wrapper is gone
+
+`Shape.splitDrafts` was removed in v4.0.0 rather than repaired, and no patch is carried.
+
+The deciding fact is not the defect, it is upstream's own verdict on the class. OCCT deleted
+`LocOpe_SplitDrafts` outright on 2026-08-07 in
+[OCCT#1442](https://github.com/Open-Cascade-SAS/OCCT/pull/1442), a "clean up dead headers" pass, and
+`git grep SplitDrafts upstream/master` returns nothing. It had no caller anywhere in the OCCT tree,
+not even a DRAW command, which is also how a defect this total survived to 8.0.1 unnoticed.
+
+So there was no upstream PR to open, nothing to fix for anyone else's benefit, and a carried patch
+would have been this project reviving a class its own maintainer had just removed, with a guaranteed
+expiry at the first kernel bump past that commit. `okf/policies/scope-boundary.md` says stay
+faithful to OCCT; wrapping what OCCT has deleted is the opposite of that.
+
+The record below is kept because the investigation is what made the decision possible, and because
+the next reader who wonders why a 1996 class is missing deserves the answer.
+
+## Disposition, as it stood before the removal
 
 - **Test**: `Tests/OCCTModelingTests/Issue1393SplitDraftsTests.swift` asserts the refusal, and says
   in its own comment that a non-nil result means a repin fixed the kernel and the test should then
@@ -64,3 +82,19 @@ happens.
 - **Not done**: no bridge-side guard. Refusing the call up front would be refusing the whole
   operation, and the `nil` it already returns is the same answer with the kernel's own reason
   behind it.
+
+## What is kept from the fix that was not taken
+
+`upstream/LocOpe_SplitDrafts_Test.cxx` is the GTest written for an upstream PR that could not be
+filed, since the class it tests no longer exists upstream. It is kept for one reason: it is the
+only executable statement of what a working `LocOpe_SplitDrafts` should produce, proven both ways
+against a patched and an unpatched kernel (`IsDone=1`, seven faces, one of them tilted by exactly
+the requested draft angle, a 10-unit cube's volume rising 1000 to 1022.04 against the wedge's
+analytic 22.04).
+
+If OCCT ever restores the class, or a downstream fork keeps it, that file is the head start. If
+nobody ever does, it is the record of what was measured before the wrapper was removed, which is
+worth more than the diff that was discarded with it.
+
+The patch itself, `0034`, was never carried. It exists only in the closed PR
+[#1627](https://github.com/SecondMouseAU/OCCTSwift/pull/1627).
diff --git a/Scripts/repro/1393-splitdrafts/upstream/LocOpe_SplitDrafts_Test.cxx b/Scripts/repro/1393-splitdrafts/upstream/LocOpe_SplitDrafts_Test.cxx
@@ -0,0 +1,90 @@
+// Copyright (c) 2026 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#include <BRep_Tool.hxx>
+#include <BRepBuilderAPI_MakeEdge.hxx>
+#include <BRepBuilderAPI_MakeWire.hxx>
+#include <BRepGProp.hxx>
+#include <BRepLib.hxx>
+#include <BRepPrimAPI_MakeBox.hxx>
+#include <Geom2d_Line.hxx>
+#include <Geom_Plane.hxx>
+#include <GProp_GProps.hxx>
+#include <LocOpe_SplitDrafts.hxx>
+#include <Precision.hxx>
+#include <TopExp_Explorer.hxx>
+#include <TopoDS.hxx>
+#include <gp_Dir2d.hxx>
+#include <gp_Pln.hxx>
+#include <gp_Pnt2d.hxx>
+
+#include <gtest/gtest.h>
+
+namespace
+{
+//! The +Z face of a box built at the origin.
+TopoDS_Face TopFace(const TopoDS_Shape& theBox, const double theHeight)
+{
+  for (TopExp_Explorer anExp(theBox, TopAbs_FACE); anExp.More(); anExp.Next())
+  {
+    const TopoDS_Face             aFace  = TopoDS::Face(anExp.Current());
+    const occ::handle<Geom_Plane> aPlane = occ::down_cast<Geom_Plane>(BRep_Tool::Surface(aFace));
+    if (!aPlane.IsNull()
+        && std::abs(aPlane->Pln().Location().Z() - theHeight) < Precision::Confusion())
+    {
+      return aFace;
+    }
+  }
+  return TopoDS_Face();
+}
+} // namespace
+
+// Perform() pipes along the intersection of the two drafted planes, which is always a line, and
+// the pipe's path is the face normal, also a line. Both were passed to GeomFill_Pipe untrimmed,
+// and GeomConvert::CurveToBSplineCurve rejects an infinite curve, so every planar request threw
+// Standard_DomainError("No such curve").
+TEST(LocOpe_SplitDraftsTest, DraftPlanarFace)
+{
+  const TopoDS_Shape aBox = BRepPrimAPI_MakeBox(10.0, 10.0, 10.0).Shape();
+  const TopoDS_Face  aTop = TopFace(aBox, 10.0);
+  ASSERT_FALSE(aTop.IsNull()) << "Top face not found";
+
+  // The splitting wire, built on the face at u = 5 so that it carries a pcurve.
+  const occ::handle<Geom_Surface> aSurf   = BRep_Tool::Surface(aTop);
+  const occ::handle<Geom2d_Line>  aLine2d = new Geom2d_Line(gp_Pnt2d(5.0, 0.0), gp_Dir2d(0.0, 1.0));
+  TopoDS_Edge anEdge = BRepBuilderAPI_MakeEdge(aLine2d, aSurf, 0.0, 10.0).Edge();
+  BRepLib::BuildCurves3d(anEdge);
+  const TopoDS_Wire aWire = BRepBuilderAPI_MakeWire(anEdge).Wire();
+
+  // The neutral plane must not be the face's own plane, or NewPlane() bails.
+  const gp_Pln aNeutral(gp_Pnt(5.0, 0.0, 0.0), gp_Dir(1.0, 0.0, 0.0));
+  const double anAngle = 10.0 * M_PI / 180.0;
+
+  LocOpe_SplitDrafts aSplit;
+  aSplit.Init(aBox);
+  ASSERT_NO_THROW(aSplit.Perform(aTop, aWire, gp_Dir(1.0, 0.0, 0.0), aNeutral, anAngle));
+  ASSERT_TRUE(aSplit.IsDone()) << "Draft split not performed";
+
+  int aNbFaces = 0;
+  for (TopExp_Explorer anExp(aSplit.Shape(), TopAbs_FACE); anExp.More(); anExp.Next())
+  {
+    ++aNbFaces;
+  }
+  EXPECT_EQ(aNbFaces, 7) << "The top face should be split in two";
+
+  // Half the top face (5 x 10) is tipped up by the draft angle, adding that wedge.
+  GProp_GProps aProps;
+  BRepGProp::VolumeProperties(aSplit.Shape(), aProps);
+  const double anExpected = 1000.0 + 0.5 * 5.0 * (5.0 * tan(anAngle)) * 10.0;
+  EXPECT_NEAR(aProps.Mass(), anExpected, 1.0e-4) << "Drafted volume is wrong";
+}
diff --git a/Sources/OCCTBridge/include/OCCTBridge.h b/Sources/OCCTBridge/include/OCCTBridge.h
@@ -539,7 +539,6 @@
 // LocOpe_Prism                        → OCCTLocOpePrism
 // LocOpe_Revol                        → OCCTLocOpeRevol
 // LocOpe_RevolutionForm               → OCCTLocOpeRevolutionForm
-// LocOpe_SplitDrafts                  → OCCTLocOpeSplitDrafts
 // LocOpe_SplitShape                   → OCCTLocOpeSplitShape*
 // LocOpe_Spliter                      → OCCTLocOpeSplitByWire*
 // LocOpe_WiresOnShape                 → OCCTLocOpeBuildWires, OCCTLocOpeSplitByWire*

diff --git a/Sources/OCCTBridge/include/OCCTBridge_Modeling.h b/Sources/OCCTBridge/include/OCCTBridge_Modeling.h
@@ -1906,31 +1906,6 @@ OCCTShapeRef _Nullable OCCTLocOpeSplitShapeByVertex(OCCTShapeRef shape,
                                                     int32_t      edgeIndex,
                                                     double       parameter);
 
-// --- LocOpe_SplitDrafts ---
-
-/// Split a face with draft angles on both sides of a wire.
-/// @param shape Shape containing the face
-/// @param faceIndex Index of the face to split
-/// @param wire Wire defining the split
-/// @param dirX,dirY,dirZ Extraction direction
-/// @param planeOriginX,Y,Z Neutral plane origin
-/// @param planeNormalX,Y,Z Neutral plane normal
-/// @param angle Draft angle in radians
-/// @return Modified shape, or NULL on failure
-OCCTShapeRef _Nullable OCCTLocOpeSplitDrafts(OCCTShapeRef shape,
-                                             int32_t      faceIndex,
-                                             OCCTShapeRef wire,
-                                             double       dirX,
-                                             double       dirY,
-                                             double       dirZ,
-                                             double       planeOriginX,
-                                             double       planeOriginY,
-                                             double       planeOriginZ,
-                                             double       planeNormalX,
-                                             double       planeNormalY,
-                                             double       planeNormalZ,
-                                             double       angle);
-
 // --- LocOpe_FindEdges ---
 
 // #613: both finders return a SELECTION of edges, not an enumeration, so the position of an entry

diff --git a/Sources/OCCTBridge/src/OCCTBridge.mm b/Sources/OCCTBridge/src/OCCTBridge.mm
@@ -373,7 +373,6 @@ void occtEnsureSignals()
 #include <LocOpe_LinearForm.hxx>
 #include <LocOpe_RevolutionForm.hxx>
 #include <LocOpe_SplitShape.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_FindEdges.hxx>
 #include <LocOpe_FindEdgesInFace.hxx>
 #include <LocOpe_CSIntersector.hxx>

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_Boolean.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_Boolean.mm
@@ -62,7 +62,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_Chamfer.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_Chamfer.mm
@@ -61,7 +61,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_Features.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_Features.mm
@@ -61,7 +61,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>
@@ -1710,67 +1709,6 @@ OCCTShapeRef OCCTLocOpeSplitShapeByVertex(OCCTShapeRef shape, int32_t edgeIndex,
   }
 }
 
-OCCTShapeRef OCCTLocOpeSplitDrafts(OCCTShapeRef shape,
-                                   int32_t      faceIndex,
-                                   OCCTShapeRef wire,
-                                   double       dirX,
-                                   double       dirY,
-                                   double       dirZ,
-                                   double       planeOriginX,
-                                   double       planeOriginY,
-                                   double       planeOriginZ,
-                                   double       planeNormalX,
-                                   double       planeNormalY,
-                                   double       planeNormalZ,
-                                   double       angle)
-{
-  // #1026: the wire's ShapeType() read below is an unguarded myTShape dereference.
-  if (!occtShapeIsPresent(shape) || !occtShapeIsPresent(wire))
-    return nullptr;
-  try
-  {
-    LocOpe_SplitDrafts splitDrafts;
-    splitDrafts.Init(shape->shape);
-
-    // #541: the shared face enumeration, so this names the face face(at:) names.
-    TopoDS_Face face = occtFaceAt(shape->shape, faceIndex);
-    if (face.IsNull())
-      return nullptr;
-
-    // Extract wire
-    TopoDS_Wire w;
-    if (wire->shape.ShapeType() == TopAbs_WIRE)
-    {
-      w = TopoDS::Wire(wire->shape);
-    }
-    else
-    {
-      for (TopExp_Explorer exp(wire->shape, TopAbs_WIRE); exp.More(); exp.Next())
-      {
-        w = TopoDS::Wire(exp.Current());
-        break;
-      }
-    }
-    if (w.IsNull())
-      return nullptr;
-
-    gp_Dir dir(dirX, dirY, dirZ);
-    gp_Pln plane(gp_Pnt(planeOriginX, planeOriginY, planeOriginZ),
-                 gp_Dir(planeNormalX, planeNormalY, planeNormalZ));
-
-    splitDrafts.Perform(face, w, dir, plane, angle);
-
-    TopoDS_Shape result = splitDrafts.Shape();
-    if (result.IsNull())
-      return nullptr;
-    return new OCCTShape(result);
-  }
-  catch (...)
-  {
-    return nullptr;
-  }
-}
-
 // #613: a finder returns a SELECTION, so the position of an entry in outEdges is a result slot, not
 // an index into anything. Swift wrote that slot number into Edge.index all the same. Measured on a
 // 10mm box (identically for the origin-centred and origin-at-zero spellings), edgesInFace(at: 3)

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_Fillet.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_Fillet.mm
@@ -61,7 +61,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_HLRProjection.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_HLRProjection.mm
@@ -61,7 +61,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_HealingSewing.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_HealingSewing.mm
@@ -62,7 +62,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_Misc.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_Misc.mm
@@ -62,7 +62,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_ShapeToolsHistory.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_ShapeToolsHistory.mm
@@ -61,7 +61,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_SolidPrimitives.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_SolidPrimitives.mm
@@ -62,7 +62,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_Sweep.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_Sweep.mm
@@ -62,7 +62,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_Transform.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_Transform.mm
@@ -62,7 +62,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>

diff --git a/Sources/OCCTBridge/src/OCCTBridge_Modeling_WireEdgeFaceBuilders.mm b/Sources/OCCTBridge/src/OCCTBridge_Modeling_WireEdgeFaceBuilders.mm
@@ -62,7 +62,6 @@
 #include <LocOpe_Prism.hxx>
 #include <LocOpe_Revol.hxx>
 #include <LocOpe_RevolutionForm.hxx>
-#include <LocOpe_SplitDrafts.hxx>
 #include <LocOpe_SplitShape.hxx>
 #include <BRepLib_MakePolygon.hxx>
 #include <BRepLib_MakeWire.hxx>