From b443d53628d935c64d01b28ee66863b3e17ffb99 Mon Sep 17 00:00:00 2001
From: emv <emv@opencascade.com>
Date: Fri, 18 Nov 2016 10:06:50 +0300
Subject: [PATCH] 0028163: 3D Offset algorithm produces incorrect result on
 attached shape in mode Complete Intersection

1. Correct building of the lists of intersection faces connected to the same vertex.
2. For the artificially invalid cases with only one invalid face avoid usage of the edges having same origins as invalid edges.
3. Test cases for the issue.
4. Test cases offset shape_type_i_c XM1, ZW*,ZX*,ZY* have been modified to provide more clear result.
5. TODO statements have been removed from the test case offset shape_type_i_c XE6 as it is OK.
6. Test case offset shape_type_i_c ZZ2 is improvement.
---
 src/BRepOffset/BRepOffset_Inter3d.cxx      |  64 +++--
 src/BRepOffset/BRepOffset_MakeOffset_1.cxx | 272 +++++++++++++--------
 tests/offset/shape_type_i_c/XE6            |  10 +-
 tests/offset/shape_type_i_c/XM1            |   6 +-
 tests/offset/shape_type_i_c/XM4            |  27 ++
 tests/offset/shape_type_i_c/XM5            |  27 ++
 tests/offset/shape_type_i_c/XM6            |  27 ++
 tests/offset/shape_type_i_c/XM7            |  27 ++
 tests/offset/shape_type_i_c/XM8            |  10 +
 tests/offset/shape_type_i_c/XM9            |  10 +
 tests/offset/shape_type_i_c/XN1            |  10 +
 tests/offset/shape_type_i_c/XN2            |  10 +
 tests/offset/shape_type_i_c/ZW1            |   5 +-
 tests/offset/shape_type_i_c/ZW2            |   5 +-
 tests/offset/shape_type_i_c/ZW3            |   5 +-
 tests/offset/shape_type_i_c/ZW4            |   5 +-
 tests/offset/shape_type_i_c/ZW5            |   5 +-
 tests/offset/shape_type_i_c/ZW6            |   5 +-
 tests/offset/shape_type_i_c/ZW7            |   5 +-
 tests/offset/shape_type_i_c/ZW8            |   5 +-
 tests/offset/shape_type_i_c/ZW9            |   5 +-
 tests/offset/shape_type_i_c/ZX1            |   5 +-
 tests/offset/shape_type_i_c/ZX2            |   5 +-
 tests/offset/shape_type_i_c/ZX3            |   5 +-
 tests/offset/shape_type_i_c/ZX4            |   5 +-
 tests/offset/shape_type_i_c/ZX9            |   5 +-
 tests/offset/shape_type_i_c/ZY1            |   5 +-
 tests/offset/shape_type_i_c/ZY4            |   5 +-
 tests/offset/shape_type_i_c/ZY5            |   5 +-
 tests/offset/shape_type_i_c/ZY6            |   5 +-
 tests/offset/shape_type_i_c/ZY7            |   5 +-
 tests/offset/shape_type_i_c/ZY8            |   5 +-
 tests/offset/shape_type_i_c/ZZ1            |   6 +-
 tests/offset/shape_type_i_c/ZZ2            |  13 +-
 34 files changed, 454 insertions(+), 165 deletions(-)
 create mode 100644 tests/offset/shape_type_i_c/XM4
 create mode 100644 tests/offset/shape_type_i_c/XM5
 create mode 100644 tests/offset/shape_type_i_c/XM6
 create mode 100644 tests/offset/shape_type_i_c/XM7
 create mode 100644 tests/offset/shape_type_i_c/XM8
 create mode 100644 tests/offset/shape_type_i_c/XM9
 create mode 100644 tests/offset/shape_type_i_c/XN1
 create mode 100644 tests/offset/shape_type_i_c/XN2

diff --git a/src/BRepOffset/BRepOffset_Inter3d.cxx b/src/BRepOffset/BRepOffset_Inter3d.cxx
index 9460d58346..b89e1f030a 100644
--- a/src/BRepOffset/BRepOffset_Inter3d.cxx
+++ b/src/BRepOffset/BRepOffset_Inter3d.cxx
@@ -443,7 +443,35 @@ void BRepOffset_Inter3d::ConnexIntByInt
   // map the shape for vertices
   if (bIsPlanar) {
     TopExp::MapShapes(SI, TopAbs_VERTEX, VEmap);
-    TopExp::MapShapesAndAncestors(SI, TopAbs_VERTEX, TopAbs_FACE, aMVF);
+    //
+    // make vertex-faces connexity map with unique ancestors
+    // TopExp::MapShapesAndAncestors(SI, TopAbs_VERTEX, TopAbs_FACE, aMVF);
+    TopExp_Explorer aExpF(SI, TopAbs_FACE);
+    for (; aExpF.More(); aExpF.Next()) {
+      const TopoDS_Shape& aF = aExpF.Current();
+      //
+      TopExp_Explorer aExpV(aF, TopAbs_VERTEX);
+      for (; aExpV.More(); aExpV.Next()) {
+        const TopoDS_Shape& aV = aExpV.Current();
+        //
+        TopTools_ListOfShape *pLF = aMVF.ChangeSeek(aV);
+        if (!pLF) {
+          pLF = &aMVF(aMVF.Add(aV, TopTools_ListOfShape()));
+          pLF->Append(aF);
+          continue;
+        }
+        //
+        TopTools_ListIteratorOfListOfShape aItLF(*pLF);
+        for (; aItLF.More(); aItLF.Next()) {
+          if (aItLF.Value().IsSame(aF)) {
+            break;
+          }
+        }
+        if (!aItLF.More()) {
+          pLF->Append(aF);
+        }
+      }
+    }
   }
   //
   TopTools_DataMapOfShapeListOfShape aDMVLF1, aDMVLF2, aDMIntFF;
@@ -462,19 +490,15 @@ void BRepOffset_Inter3d::ConnexIntByInt
       if (aLF.Extent() < 2) {
         continue;
       }
-      //
-      // find pairs in which the vertex is alone (not connected to shared edges)
+      // build lists of faces connected to the same vertex by looking for
+      // the pairs in which the vertex is alone (not connected to shared edges)
       TopTools_ListOfShape aLF1, aLF2;
-      Standard_Boolean bVertexOnly = Standard_False;
-      TopTools_MapOfShape aMFence;
       //
       it.Initialize(aLF);
       for (; it.More(); it.Next()) {
-        const TopoDS_Face& aFV1 = *(TopoDS_Face*)&it.Value();
-        if (!aMFence.Add(aFV1)) {
-          continue;
-        }
+        const TopoDS_Shape& aFV1 = it.Value();
         //
+        // get edges of first face connected to current vertex
         TopTools_MapOfShape aME;
         TopExp_Explorer aExp(aFV1, TopAbs_EDGE);
         for (; aExp.More(); aExp.Next()) {
@@ -488,37 +512,31 @@ void BRepOffset_Inter3d::ConnexIntByInt
           }
         }
         //
-        it1.Initialize(aLF);
+        // get to the next face in the list
+        it1 = it;
         for (it1.Next(); it1.More(); it1.Next()) {
-          const TopoDS_Face& aFV2 = *(TopoDS_Face*)&it1.Value();
-          if (aMFence.Contains(aFV2)) {
-            continue;
-          }
+          const TopoDS_Shape& aFV2 = it1.Value();
           //
-          bVertexOnly = Standard_True;
           aExp.Init(aFV2, TopAbs_EDGE);
           for (; aExp.More(); aExp.Next()) {
             const TopoDS_Shape& aEV2 = aExp.Current();
             if (aME.Contains(aEV2)) {
-              bVertexOnly = Standard_False;
               break;
             }
           }
           //
-          if (bVertexOnly) {
+          if (!aExp.More()) {
+            // faces share only vertex - make pair for intersection
             aLF1.Append(aFV1);
             aLF2.Append(aFV2);
-            aMFence.Add(aFV2);
           }
         }
       }
       //
-      if (aLF1.IsEmpty()) {
-        continue;
+      if (aLF1.Extent()) {
+        aDMVLF1.Bind(aS, aLF1);
+        aDMVLF2.Bind(aS, aLF2);
       }
-      //
-      aDMVLF1.Bind(aS, aLF1);
-      aDMVLF2.Bind(aS, aLF2);
     }
   }
   //
diff --git a/src/BRepOffset/BRepOffset_MakeOffset_1.cxx b/src/BRepOffset/BRepOffset_MakeOffset_1.cxx
index abc54f034a..0a4b37d7de 100644
--- a/src/BRepOffset/BRepOffset_MakeOffset_1.cxx
+++ b/src/BRepOffset/BRepOffset_MakeOffset_1.cxx
@@ -783,19 +783,19 @@ void BuildSplitsOfFaces(const TopTools_ListOfShape& theLF,
       TopTools_ListOfShape aLFImages1;
       BuildSplitsOfFace(aF, aCE1, Standard_False, theFacesOrigins, aLFImages1);
       //
-      // additionally check if newly created faces are not the same
-      Standard_Boolean bAllInv = Standard_True;
+      // check if the rebuilding has added some new faces to the splits
       for (TopTools_ListIteratorOfListOfShape aItLFIm(aLFImages1); aItLFIm.More();)
       {
+        Standard_Boolean bAllInv = Standard_True;
         const TopoDS_Shape& aFIm = aItLFIm.Value();
         TopExp_Explorer aExpE(aFIm, TopAbs_EDGE);
         for (; aExpE.More(); aExpE.Next()) {
           const TopoDS_Shape& aE = aExpE.Current();
-          if (!aMapEInv.Contains(aE) && !aMENInv.Contains(aE)) {
-            break;
-          }
-          else if (bAllInv) {
-            bAllInv = aMapEInv.Contains(aE);
+          if (!aMapEInv.Contains(aE)) {
+            bAllInv = Standard_False;
+            if (!aMENInv.Contains(aE)) {
+              break;
+            }
           }
         }
         //
@@ -1314,12 +1314,14 @@ Standard_Boolean CheckIfArtificial(const TopoDS_Shape& theF,
     TopExp_Explorer aExpV(aEInv, TopAbs_VERTEX);
     for (; aExpV.More(); aExpV.Next()) {
       const TopoDS_Shape& aVEInv = aExpV.Current();
-      if (!aMEUsed.Contains(aVEInv) && aMVE.Contains(aVEInv)) {
-        const TopTools_ListOfShape& aLENInv = aMVE.FindFromKey(aVEInv);
-        TopTools_ListIteratorOfListOfShape aItLEInv(aLENInv);
+      const TopTools_ListOfShape* pLENInv = aMVE.Seek(aVEInv);
+      if (pLENInv) {
+        TopTools_ListIteratorOfListOfShape aItLEInv(*pLENInv);
         for (; aItLEInv.More(); aItLEInv.Next()) {
           const TopoDS_Shape& aENInv = aItLEInv.Value();
-          theMENInv.Add(aENInv);
+          if (!aMEUsed.Contains(aENInv)) {
+            theMENInv.Add(aENInv);
+          }
         }
       }
     }
@@ -1395,7 +1397,7 @@ void FindInvalidEdges(const TopoDS_Face& theF,
   // be defined by the edges on the original face adjacent to the connection vertex
   //
   const TopoDS_Face& aFOr = *(TopoDS_Face*)&theFacesOrigins.Find(theF);
-  // invald edges
+  // invalid edges
   TopTools_IndexedMapOfShape aMEInv;
   // valid edges
   TopTools_MapOfShape aMEVal;
@@ -1479,6 +1481,11 @@ void FindInvalidEdges(const TopoDS_Face& theF,
       TopTools_MapOfShape aME, aMV;
       Standard_Boolean bInvalid = Standard_False, bChecked = Standard_False;
       Standard_Integer aNbP = NbPoints(aEIm);
+      Standard_Boolean bUseVertex = !aNbVOr ? Standard_False :
+        (aNbVOr == 1 &&
+         aDMEF.FindFromKey(aEIm).Extent() == 1 &&
+         !theOEOrigins.IsBound(aEIm));
+      //
       aItLEO.Initialize(aLEOr);
       for (; aItLEO.More(); aItLEO.Next()) {
         const TopoDS_Shape& aSOr = aItLEO.Value();
@@ -1487,18 +1494,9 @@ void FindInvalidEdges(const TopoDS_Face& theF,
         TopoDS_Shape aEOrF;
         if (bVertex) {
           // for some cases it is impossible to check the validity of the edge
-          if (aNbVOr > 1) {
+          if (!bUseVertex) {
             continue;
           }
-          //
-          if (aDMEF.FindFromKey(aEIm).Extent() > 1) {
-            continue;
-          }
-          //
-          if (theOEOrigins.IsBound(aEIm)) {
-            continue;
-          }
-          //
           // find edges on the original face adjacent to this vertex
           if (aDMVEFOr.IsEmpty()) {
             // fill the map
@@ -1579,8 +1577,9 @@ void FindInvalidEdges(const TopoDS_Face& theF,
       }
       //
       // check if the edge has been inverted
-      Standard_Boolean bInverted = CheckInverted(aEIm, aFOr, theOEImages, theOEOrigins,
-        theEdgesOrigins, aDMEF, aDMVE, aMEdges, theMEInverted);
+      Standard_Boolean bInverted = !aNbE ? Standard_False :
+        CheckInverted(aEIm, aFOr, theOEImages, theOEOrigins,
+          theEdgesOrigins, aDMEF, aDMVE, aMEdges, theMEInverted);
       //
       if (!bInverted || !aNbVOr) {
         theValidEdges.Add(aEIm);
@@ -1908,10 +1907,6 @@ Standard_Boolean CheckInverted(const TopoDS_Edge& theEIm,
     return Standard_False;
   }
   //
-  if (theMEInverted.Contains(theEIm)) {
-    return Standard_True;
-  }
-  //
   // it is necessary to compare the direction from first vertex
   // to the last vertex on the original edge with the
   // same direction on the new edge. If the directions
@@ -2013,7 +2008,7 @@ Standard_Boolean CheckInverted(const TopoDS_Edge& theEIm,
           if (aEO.ShapeType() == TopAbs_EDGE && aMFence.Add(aEO)) {
             TopoDS_Shape aEOin;
             if (FindShape(aEO, theFOr, aEOin)) {
-              aLOE.Append(aEO);
+              AppendToList(aLOE, aEO);
             }
           }
         }
@@ -2512,6 +2507,7 @@ void RemoveInsideFaces(TopTools_IndexedDataMapOfShapeListOfShape& theFImages,
   //
   TopoDS_Compound aSolids;
   BRep_Builder().MakeCompound(aSolids);
+  TopTools_MapOfShape aMFKeep;
   //
   TopExp_Explorer aExpS(aSols, TopAbs_SOLID);
   for (; aExpS.More(); aExpS.Next()) {
@@ -2538,7 +2534,9 @@ void RemoveInsideFaces(TopTools_IndexedDataMapOfShapeListOfShape& theFImages,
         const TopoDS_Shape& aFS = aExpF.Current();
         //
         if (aMFToRem.Contains(aFS)) {
-          aMFToRem.Remove(aFS);
+          if (!aMFKeep.Add(aFS)) {
+            aMFKeep.Remove(aFS);
+          }
         }
         else {
           aMFToRem.Add(aFS);
@@ -2551,6 +2549,11 @@ void RemoveInsideFaces(TopTools_IndexedDataMapOfShapeListOfShape& theFImages,
     }
   }
   //
+  TopTools_MapIteratorOfMapOfShape aItM(aMFKeep);
+  for (; aItM.More(); aItM.Next()) {
+    aMFToRem.Remove(aItM.Value());
+  }
+  //
   // remove newly found internal faces
   RemoveValidSplits(aMFToRem, theFImages, aMV, theMERemoved);
   RemoveInvalidSplits(aMFToRem, theArtInvFaces, theInvEdges, theInvFaces, aMV, theMERemoved);
@@ -3320,85 +3323,136 @@ void IntersectFaces(const TopTools_IndexedDataMapOfShapeListOfShape& theFToRebui
   // when dealing with artificially invalid faces for intersection to be
   // complete we need to use not only invalid edges, but also the 
   // edges connected to invalid ones
-  TopTools_MapOfShape aMEAlone, aMFence, aMVEInv;
-  TopTools_IndexedDataMapOfShapeListOfShape aDMVEVal;
-  //
+
+  // find blocks of artificially invalid faces
+  TopTools_DataMapOfShapeShape aDMFImF;
+  TopoDS_Compound aCFArt;
+  BRep_Builder().MakeCompound(aCFArt);
   TopTools_DataMapIteratorOfDataMapOfShapeShape aItM(theArtInvFaces);
   for (; aItM.More(); aItM.Next()) {
     const TopoDS_Shape& aF = aItM.Key();
     const TopTools_ListOfShape& aLFInv = theInvFaces.FindFromKey(aF);
     aItLF.Initialize(aLFInv);
     for (; aItLF.More(); aItLF.Next()) {
-      const TopoDS_Shape& aFInv = aItLF.Value();
-      for (TopExp_Explorer aExp(aFInv, TopAbs_EDGE); aExp.More(); aExp.Next())
-      {
-        const TopoDS_Shape& aE = aExp.Current();
-        if (theInvEdges.Contains(aE)) {
-          for (TopoDS_Iterator aItV(aE); aItV.More(); aItV.Next()) {
-            aMVEInv.Add(aItV.Value());
-          }
-          continue;
-        }
-        if (aMFence.Add(aE)) {
-          TopExp::MapShapesAndAncestors(aE, TopAbs_VERTEX, TopAbs_EDGE, aDMVEVal);
-        }
-      }
+      BRep_Builder().Add(aCFArt, aItLF.Value());
+      aDMFImF.Bind(aItLF.Value(), aF);
     }
   }
   //
-  // collect edges with free vertices
-  Standard_Integer aNbV = aDMVEVal.Extent();
-  for (i = 1; i <= aNbV; ++i) {
-    const TopoDS_Shape& aV = aDMVEVal.FindKey(i);
-    if (!aMVEInv.Contains(aV)) {
-      continue;
+  // make connexity blocks
+  TopTools_ListOfShape aLCBArt;
+  BOPTools_AlgoTools::MakeConnexityBlocks(aCFArt, TopAbs_VERTEX, TopAbs_FACE, aLCBArt);
+  //
+  // alone edges
+  TopTools_MapOfShape aMEAlone;
+  //
+  TopTools_ListIteratorOfListOfShape aItLCBArt(aLCBArt);
+  for (; aItLCBArt.More(); aItLCBArt.Next()) {
+    const TopoDS_Shape& aCB = aItLCBArt.Value();
+    //
+    // check if aCB contains splits of only one offset face
+    TopTools_MapOfShape aMFArt;
+    TopExp_Explorer aExpF(aCB, TopAbs_FACE);
+    for (; aExpF.More(); aExpF.Next()) {
+      aMFArt.Add(aDMFImF.Find(aExpF.Current()));
     }
     //
-    const TopTools_ListOfShape& aLEV = aDMVEVal(i);
-    if (aLEV.Extent() > 1) {
-      continue;
-    }
+    Standard_Boolean bAlone = (aMFArt.Extent() == 1);
     //
-    const TopoDS_Shape& aE = aLEV.First();
-    aMEAlone.Add(aE);
+    // vertices on invalid edges
+    TopTools_MapOfShape aMVEInv;
+    TopTools_MapOfShape aMFence;
+    // edges that should not be marked as alone - edges having same origins as invalid ones
+    TopTools_MapOfShape aMEAvoid;
+    // map to find alone edges by looking for free vertices
+    TopTools_IndexedDataMapOfShapeListOfShape aDMVEVal;
     //
-    // if this alone edge adds nothing to the intersection list
-    // it means that the origin of this edge has been split and we need to
-    // add the neigboring images of the same origins
-    if (aDMSF.Find(aE).Extent() > 1) {
-      continue;
-    }
-    //
-    // check also its vertices
-    TopoDS_Iterator aItE(aE);
-    for (; aItE.More(); aItE.Next()) {
-      const TopoDS_Shape& aVE = aItE.Value();
-      if (aDMSF.Find(aVE).Extent() > 2) {
-        break;
+    TopExp_Explorer aExpE(aCB, TopAbs_EDGE);
+    for (; aExpE.More(); aExpE.Next()) {
+      const TopoDS_Shape& aE = aExpE.Current();
+      if (theInvEdges.Contains(aE)) {
+        for (TopoDS_Iterator aItV(aE); aItV.More(); aItV.Next()) {
+          aMVEInv.Add(aItV.Value());
+        }
+        //
+        if (bAlone) {
+          const TopTools_ListOfShape *pLEOr = theOEOrigins.Seek(aE);
+          if (pLEOr) {
+            TopTools_ListIteratorOfListOfShape aItLEOr(*pLEOr);
+            for (; aItLEOr.More(); aItLEOr.Next()) {
+              TopTools_ListIteratorOfListOfShape aItLEIm(theOEImages.Find(aItLEOr.Value()));
+              for (; aItLEIm.More(); aItLEIm.Next()) {
+                aMEAvoid.Add(aItLEIm.Value());
+              }
+            }
+          }
+        }
+        continue;
+      }
+      //
+      if (aMFence.Add(aE)) {
+        TopExp::MapShapesAndAncestors(aE, TopAbs_VERTEX, TopAbs_EDGE, aDMVEVal);
       }
     }
     //
-    if (aItE.More()) {
-      continue;
-    }
-    //
-    // the edge is useless - look for other images
-    const TopTools_ListOfShape *pLEOr = theOEOrigins.Seek(aE);
-    if (!pLEOr) {
-      continue;
-    }
-    //
-    TopTools_ListIteratorOfListOfShape aItLEOr(*pLEOr);
-    for (; aItLEOr.More(); aItLEOr.Next()) {
-      const TopoDS_Shape& aEOr = aItLEOr.Value();
+    // find edges with free vertices
+    Standard_Integer aNbV = aDMVEVal.Extent();
+    for (i = 1; i <= aNbV; ++i) {
+      const TopoDS_Shape& aV = aDMVEVal.FindKey(i);
+      if (!aMVEInv.Contains(aV)) {
+        continue;
+      }
       //
-      const TopTools_ListOfShape& aLEIm = theOEImages.Find(aEOr);
-      TopTools_ListIteratorOfListOfShape aItLEIm(aLEIm);
-      for (; aItLEIm.More(); aItLEIm.Next()) {
-        const TopoDS_Shape& aEIm = aItLEIm.Value();
+      const TopTools_ListOfShape& aLEV = aDMVEVal(i);
+      if (aLEV.Extent() > 1) {
+        continue;
+      }
+      //
+      const TopoDS_Shape& aE = aLEV.First();
+      if (aMEAvoid.Contains(aE)) {
+        continue;
+      }
+      //
+      aMEAlone.Add(aE);
+      //
+      // if this alone edge adds nothing to the intersection list
+      // it means that the origin of this edge has been split and we need to
+      // add the neighboring images of the same origins
+      if (aDMSF.Find(aE).Extent() > 1) {
+        continue;
+      }
+      //
+      // check also its vertices
+      TopoDS_Iterator aItE(aE);
+      for (; aItE.More(); aItE.Next()) {
+        const TopoDS_Shape& aVE = aItE.Value();
+        if (aDMSF.Find(aVE).Extent() > 2) {
+          break;
+        }
+      }
+      //
+      if (aItE.More()) {
+        continue;
+      }
+      //
+      // the edge is useless - look for other images
+      const TopTools_ListOfShape *pLEOr = theOEOrigins.Seek(aE);
+      if (!pLEOr) {
+        continue;
+      }
+      //
+      TopTools_ListIteratorOfListOfShape aItLEOr(*pLEOr);
+      for (; aItLEOr.More(); aItLEOr.Next()) {
+        const TopoDS_Shape& aEOr = aItLEOr.Value();
         //
-        if (aMFence.Contains(aEIm)) {
-          aMEAlone.Add(aEIm);
+        const TopTools_ListOfShape& aLEIm = theOEImages.Find(aEOr);
+        TopTools_ListIteratorOfListOfShape aItLEIm(aLEIm);
+        for (; aItLEIm.More(); aItLEIm.Next()) {
+          const TopoDS_Shape& aEIm = aItLEIm.Value();
+          //
+          if (aMFence.Contains(aEIm)) {
+            aMEAlone.Add(aEIm);
+          }
         }
       }
     }
@@ -3958,17 +4012,24 @@ void ProcessCommonEdges(const TopTools_ListOfShape& theLEC,
       aItLE.Initialize(theLEC);
       for (; aItLE.More(); aItLE.Next()) {
         const TopoDS_Shape& aEC = aItLE.Value();
-        if (theAllInvs.Contains(aEC) || theInvEdges.Contains(aEC)) {
-          return;
-        }
-        //
-        TopoDS_Iterator aItV(aEC);
-        for (; aItV.More(); aItV.Next()) {
-          if (theAllInvs.Contains(aItV.Value())) {
+        // check if all images of the origin of this edge
+        // are not connected to any invalidity
+        const TopoDS_Shape& aEInt = theETrimEInf.Find(aEC);
+        const TopTools_ListOfShape& aLVE = theMEInfETrim.Find(aEInt);
+        TopTools_ListIteratorOfListOfShape aItLVE(aLVE);
+        for (; aItLVE.More(); aItLVE.Next()) {
+          const TopoDS_Shape& aECx = aItLVE.Value();
+          if (theAllInvs.Contains(aECx) || theInvEdges.Contains(aECx)) {
             return;
           }
+          //
+          TopoDS_Iterator aItV(aECx);
+          for (; aItV.More(); aItV.Next()) {
+            if (theAllInvs.Contains(aItV.Value())) {
+              return;
+            }
+          }
         }
-        //
         // use only one element
         if (aLEC.IsEmpty()) {
           aLEC.Append(aEC);
@@ -4514,6 +4575,7 @@ void UpdateValidEdges(const TopTools_IndexedDataMapOfShapeListOfShape& theFImage
   // back connection from edges to faces
   TopTools_DataMapOfShapeListOfShape aMELF;
   //
+  TopTools_MapOfShape aMETmp;
   Standard_Integer i, aNb = theFLE.Extent();
   for (i = 1; i <= aNb; ++i) {
     const TopoDS_Face& aF = TopoDS::Face(theFLE.FindKey(i));
@@ -4522,6 +4584,11 @@ void UpdateValidEdges(const TopTools_IndexedDataMapOfShapeListOfShape& theFImage
     TopTools_ListIteratorOfListOfShape aItLE(aLEInt);
     for (; aItLE.More(); aItLE.Next()) {
       const TopoDS_Shape& aE = aItLE.Value();
+      if ((theMECheckExt.Contains(aE) || aMETmp.Contains(aE)) && !theEImages.IsBound(aE)) {
+        theMECheckExt.Remove(aE);
+        aMETmp.Add(aE);
+        continue;
+      }
       TopTools_ListOfShape* pLF = aMELF.ChangeSeek(aE);
       if (!pLF) {
         pLF = aMELF.Bound(aE, TopTools_ListOfShape());
@@ -4728,6 +4795,8 @@ void TrimNewIntersectionEdges(const TopTools_ListOfShape& theLE,
   for (; aIt.More(); aIt.Next()) {
     const TopoDS_Shape& aE = aIt.Value();
     //
+    Standard_Boolean bCheckExt = theMECheckExt.Remove(aE);
+    //
     Standard_Boolean bOld = theEETrim.IsBound(aE);
     if (bOld) {
       const TopTools_ListOfShape& aLET = theEETrim.Find(aE);
@@ -4820,7 +4889,6 @@ void TrimNewIntersectionEdges(const TopTools_ListOfShape& theLE,
       }
     }
     //
-    Standard_Boolean bCheckExt = theMECheckExt.Contains(aE);
     if (aLEIm.IsEmpty()) {
       theEImages.UnBind(aE);
     }
@@ -4846,10 +4914,6 @@ void TrimNewIntersectionEdges(const TopTools_ListOfShape& theLE,
         }
       }
     }
-    //
-    if (bCheckExt) {
-      theMECheckExt.Remove(aE);
-    }
   }
 }
 
diff --git a/tests/offset/shape_type_i_c/XE6 b/tests/offset/shape_type_i_c/XE6
index ec54beae60..f462c92068 100644
--- a/tests/offset/shape_type_i_c/XE6
+++ b/tests/offset/shape_type_i_c/XE6
@@ -1,10 +1,10 @@
-puts "TODO CR27414 ALL: Error : The area of result shape is"
-puts "TODO CR27414 ALL: Error : The volume of result shape is"
-
 restore [locate_data_file bug26917_dom-7724_trim5.brep] s
 
 OFFSETSHAPE 15 {} $calcul $type
 
-checkprops result -v 0 -s 0
+checkprops result -v 596571 -s 50145.4
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 9 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/XM1 b/tests/offset/shape_type_i_c/XM1
index 747eeadea4..f84299b516 100644
--- a/tests/offset/shape_type_i_c/XM1
+++ b/tests/offset/shape_type_i_c/XM1
@@ -1,10 +1,12 @@
 restore [locate_data_file bug28046_rm-107_merged_input.brep] s
 
-OFFSETSHAPE 8 {} $calcul $type
+offsetparameter 1e-7 c i r
+offsetload s 8
+offsetperform result
 
 checkprops result -v 4.40128e+007 -s 1.81672e+006
 
 unifysamedom result_unif result
-checknbshapes result_unif -face 64 -shell 1
+checknbshapes result_unif -edge 186 -face 64 -shell 1
 
 checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/XM4 b/tests/offset/shape_type_i_c/XM4
new file mode 100644
index 0000000000..53fa225192
--- /dev/null
+++ b/tests/offset/shape_type_i_c/XM4
@@ -0,0 +1,27 @@
+restore [locate_data_file bug28163_merged_input.brep] s
+
+offsetparameter 1e-7 c i
+offsetload s 4
+foreach f [explode s f] {
+  mksurface surf $f
+  set found [regexp {Axis   :([-0-9.+eE]*), ([-0-9.+eE]*), ([-0-9.+eE]*)} [dump surf] full x y z]
+  if {$found && abs(abs($z) - 1) < 1.e-7} {
+    offsetonface $f 3
+  } else {
+    if { y < -0.7 } {
+      offsetonface $f 5
+    } else {
+      if { y > 0.7 } {
+        offsetonface $f 3
+      }
+    }
+  }
+}
+offsetperform result
+
+checkprops result -v 4.27764e+007 -s 1.70699e+006
+
+unifysamedom result_unif result
+checknbshapes result_unif -face 413 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/XM5 b/tests/offset/shape_type_i_c/XM5
new file mode 100644
index 0000000000..6f95451eab
--- /dev/null
+++ b/tests/offset/shape_type_i_c/XM5
@@ -0,0 +1,27 @@
+restore [locate_data_file bug28163_merged_input_trim1.brep] s
+
+offsetparameter 1e-7 c i
+offsetload s 4
+foreach f [explode s f] {
+  mksurface surf $f
+  set found [regexp {Axis   :([-0-9.+eE]*), ([-0-9.+eE]*), ([-0-9.+eE]*)} [dump surf] full x y z]
+  if {$found && abs(abs($z) - 1) < 1.e-7} {
+    offsetonface $f 3
+  } else {
+    if { y < -0.7 } {
+      offsetonface $f 5
+    } else {
+      if { y > 0.7 } {
+        offsetonface $f 3
+      }
+    }
+  }
+}
+offsetperform result
+
+checkprops result -v 1.62872e+007 -s 600815
+
+unifysamedom result_unif result
+checknbshapes result_unif -face 90 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/XM6 b/tests/offset/shape_type_i_c/XM6
new file mode 100644
index 0000000000..73860d1a62
--- /dev/null
+++ b/tests/offset/shape_type_i_c/XM6
@@ -0,0 +1,27 @@
+restore [locate_data_file bug28163_merged_input_trim3.brep] s
+
+offsetparameter 1e-7 c i
+offsetload s 4
+foreach f [explode s f] {
+  mksurface surf $f
+  set found [regexp {Axis   :([-0-9.+eE]*), ([-0-9.+eE]*), ([-0-9.+eE]*)} [dump surf] full x y z]
+  if {$found && abs(abs($z) - 1) < 1.e-7} {
+    offsetonface $f 3
+  } else {
+    if { y < -0.7 } {
+      offsetonface $f 5
+    } else {
+      if { y > 0.7 } {
+        offsetonface $f 3
+      }
+    }
+  }
+}
+offsetperform result
+
+checkprops result -v 1.23529e+006 -s 103271
+
+unifysamedom result_unif result
+checknbshapes result_unif -face 35 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/XM7 b/tests/offset/shape_type_i_c/XM7
new file mode 100644
index 0000000000..d5262d3d8d
--- /dev/null
+++ b/tests/offset/shape_type_i_c/XM7
@@ -0,0 +1,27 @@
+restore [locate_data_file bug28163_merged_input_trim5.brep] s
+
+offsetparameter 1e-7 c i
+offsetload s 4
+foreach f [explode s f] {
+  mksurface surf $f
+  set found [regexp {Axis   :([-0-9.+eE]*), ([-0-9.+eE]*), ([-0-9.+eE]*)} [dump surf] full x y z]
+  if {$found && abs(abs($z) - 1) < 1.e-7} {
+    offsetonface $f 3
+  } else {
+    if { y < -0.7 } {
+      offsetonface $f 5
+    } else {
+      if { y > 0.7 } {
+        offsetonface $f 3
+      }
+    }
+  }
+}
+offsetperform result
+
+checkprops result -v 195034 -s 24982.5
+
+unifysamedom result_unif result
+checknbshapes result_unif -face 12 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/XM8 b/tests/offset/shape_type_i_c/XM8
new file mode 100644
index 0000000000..5bf3cae8f8
--- /dev/null
+++ b/tests/offset/shape_type_i_c/XM8
@@ -0,0 +1,10 @@
+restore [locate_data_file bug28163_merged_input.brep] s
+
+OFFSETSHAPE 4 {} $calcul $type
+
+checkprops result -v 4.44822e+007 -s 1.70739e+006
+
+unifysamedom result_unif result
+checknbshapes result_unif -face 423 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/XM9 b/tests/offset/shape_type_i_c/XM9
new file mode 100644
index 0000000000..654b38d47e
--- /dev/null
+++ b/tests/offset/shape_type_i_c/XM9
@@ -0,0 +1,10 @@
+restore [locate_data_file bug28163_merged_input_trim1.brep] s
+
+OFFSETSHAPE 4 {} $calcul $type
+
+checkprops result -v 1.68905e+007 -s 606317
+
+unifysamedom result_unif result
+checknbshapes result_unif -face 91 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/XN1 b/tests/offset/shape_type_i_c/XN1
new file mode 100644
index 0000000000..87b0dbff9f
--- /dev/null
+++ b/tests/offset/shape_type_i_c/XN1
@@ -0,0 +1,10 @@
+restore [locate_data_file bug28163_merged_input_trim3.brep] s
+
+OFFSETSHAPE 4 {} $calcul $type
+
+checkprops result -v 1.34032e+006 -s 107264
+
+unifysamedom result_unif result
+checknbshapes result_unif -face 36 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/XN2 b/tests/offset/shape_type_i_c/XN2
new file mode 100644
index 0000000000..dc691b09a3
--- /dev/null
+++ b/tests/offset/shape_type_i_c/XN2
@@ -0,0 +1,10 @@
+restore [locate_data_file bug28163_merged_input_trim5.brep] s
+
+OFFSETSHAPE 4 {} $calcul $type
+
+checkprops result -v 220952 -s 26863.2
+
+unifysamedom result_unif result
+checknbshapes result_unif -face 12 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZW1 b/tests/offset/shape_type_i_c/ZW1
index ed536b138f..e5e99d3606 100644
--- a/tests/offset/shape_type_i_c/ZW1
+++ b/tests/offset/shape_type_i_c/ZW1
@@ -5,4 +5,7 @@ OFFSETSHAPE 43.7 {} $calcul $type
 checkprops result -v 2.70147e+009
 checkprops result -s 1.63922e+007
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 38 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZW2 b/tests/offset/shape_type_i_c/ZW2
index de81d16f66..00f26552ee 100644
--- a/tests/offset/shape_type_i_c/ZW2
+++ b/tests/offset/shape_type_i_c/ZW2
@@ -5,4 +5,7 @@ OFFSETSHAPE 43.7 {} $calcul $type
 checkprops result -v 4.55952e+006
 checkprops result -s 178524
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 14 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZW3 b/tests/offset/shape_type_i_c/ZW3
index 5f784419dc..2ee1535b50 100644
--- a/tests/offset/shape_type_i_c/ZW3
+++ b/tests/offset/shape_type_i_c/ZW3
@@ -5,4 +5,7 @@ OFFSETSHAPE 14 {} $calcul $type
 checkprops result -v 702756
 checkprops result -s 58381.3
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 9 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZW4 b/tests/offset/shape_type_i_c/ZW4
index cae34a8e19..3b3eff909e 100644
--- a/tests/offset/shape_type_i_c/ZW4
+++ b/tests/offset/shape_type_i_c/ZW4
@@ -5,4 +5,7 @@ OFFSETSHAPE 43.7 {} $calcul $type
 checkprops result -v 3.77467e+006
 checkprops result -s 155537
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 8 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZW5 b/tests/offset/shape_type_i_c/ZW5
index 61a523eaf2..96d76f41b5 100644
--- a/tests/offset/shape_type_i_c/ZW5
+++ b/tests/offset/shape_type_i_c/ZW5
@@ -5,4 +5,7 @@ OFFSETSHAPE 4 {} $calcul $type
 checkprops result -v 3771.44
 checkprops result -s 1506.76
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 12 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZW6 b/tests/offset/shape_type_i_c/ZW6
index ce6fc96dc4..a01c955830 100644
--- a/tests/offset/shape_type_i_c/ZW6
+++ b/tests/offset/shape_type_i_c/ZW6
@@ -5,4 +5,7 @@ OFFSETSHAPE 5 {} $calcul $type
 checkprops result -v 5453.96
 checkprops result -s 1912.14
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 13 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZW7 b/tests/offset/shape_type_i_c/ZW7
index 1ae6cf9138..e7416e60a4 100644
--- a/tests/offset/shape_type_i_c/ZW7
+++ b/tests/offset/shape_type_i_c/ZW7
@@ -9,4 +9,7 @@ offsetperform result
 checkprops result -v 5530.7
 checkprops result -s 1919.49
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 13 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZW8 b/tests/offset/shape_type_i_c/ZW8
index b47a2963e5..eb0b0e2d76 100644
--- a/tests/offset/shape_type_i_c/ZW8
+++ b/tests/offset/shape_type_i_c/ZW8
@@ -5,4 +5,7 @@ OFFSETSHAPE 15 {} $calcul $type
 checkprops result -v 48955.7
 checkprops result -s 8048.95
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 8 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZW9 b/tests/offset/shape_type_i_c/ZW9
index c97b3d69f7..50ce6f0615 100644
--- a/tests/offset/shape_type_i_c/ZW9
+++ b/tests/offset/shape_type_i_c/ZW9
@@ -5,4 +5,7 @@ OFFSETSHAPE 6 {} $calcul $type
 checkprops result -v 7543.63
 checkprops result -s 2359.85
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 13 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZX1 b/tests/offset/shape_type_i_c/ZX1
index 3910b68835..ac5f60e851 100644
--- a/tests/offset/shape_type_i_c/ZX1
+++ b/tests/offset/shape_type_i_c/ZX1
@@ -5,4 +5,7 @@ OFFSETSHAPE 43 {} $calcul $type
 checkprops result -v 7.05903e+008
 checkprops result -s 5.59084e+006
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 21 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZX2 b/tests/offset/shape_type_i_c/ZX2
index 6bd9877625..17e216662e 100644
--- a/tests/offset/shape_type_i_c/ZX2
+++ b/tests/offset/shape_type_i_c/ZX2
@@ -5,4 +5,7 @@ OFFSETSHAPE 35 {} $calcul $type
 checkprops result -v 7.94674e+008
 checkprops result -s 6.11963e+006
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 22 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZX3 b/tests/offset/shape_type_i_c/ZX3
index 5936be0e29..22979a735a 100644
--- a/tests/offset/shape_type_i_c/ZX3
+++ b/tests/offset/shape_type_i_c/ZX3
@@ -5,4 +5,7 @@ OFFSETSHAPE 43 {} $calcul $type
 checkprops result -v 7.05903e+008
 checkprops result -s 5.59084e+006
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 21 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZX4 b/tests/offset/shape_type_i_c/ZX4
index de7b0afebb..993428c5f4 100644
--- a/tests/offset/shape_type_i_c/ZX4
+++ b/tests/offset/shape_type_i_c/ZX4
@@ -5,4 +5,7 @@ OFFSETSHAPE 43 {} $calcul $type
 checkprops result -v 9.12393e+008
 checkprops result -s 7.01321e+006
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 21 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZX9 b/tests/offset/shape_type_i_c/ZX9
index 86445e1bea..fad0518ec3 100644
--- a/tests/offset/shape_type_i_c/ZX9
+++ b/tests/offset/shape_type_i_c/ZX9
@@ -5,4 +5,7 @@ OFFSETSHAPE 43 {} $calcul $type
 checkprops result -v 5.23391e+008
 checkprops result -s 4.7898e+006
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 22 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZY1 b/tests/offset/shape_type_i_c/ZY1
index 070bfda432..20c26e739b 100644
--- a/tests/offset/shape_type_i_c/ZY1
+++ b/tests/offset/shape_type_i_c/ZY1
@@ -5,4 +5,7 @@ OFFSETSHAPE 43 {} $calcul $type
 checkprops result -v 1.58077e+009
 checkprops result -s 1.04396e+007
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 38 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZY4 b/tests/offset/shape_type_i_c/ZY4
index c96b9e09e7..d887861a73 100644
--- a/tests/offset/shape_type_i_c/ZY4
+++ b/tests/offset/shape_type_i_c/ZY4
@@ -5,4 +5,7 @@ OFFSETSHAPE 43 {} $calcul $type
 checkprops result -v 2.09462e+009
 checkprops result -s 1.32364e+007
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 38 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZY5 b/tests/offset/shape_type_i_c/ZY5
index a6b5f5d523..83c94c169a 100644
--- a/tests/offset/shape_type_i_c/ZY5
+++ b/tests/offset/shape_type_i_c/ZY5
@@ -5,4 +5,7 @@ OFFSETSHAPE 43 {} $calcul $type
 checkprops result -v 7.05903e+008
 checkprops result -s 5.59084e+006
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 21 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZY6 b/tests/offset/shape_type_i_c/ZY6
index 0b63ea5457..5cb63eff3b 100644
--- a/tests/offset/shape_type_i_c/ZY6
+++ b/tests/offset/shape_type_i_c/ZY6
@@ -5,4 +5,7 @@ OFFSETSHAPE 43 {} $calcul $type
 checkprops result -v 5.23391e+008
 checkprops result -s 4.7898e+006
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 22 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZY7 b/tests/offset/shape_type_i_c/ZY7
index a93a4246a1..f5dc033655 100644
--- a/tests/offset/shape_type_i_c/ZY7
+++ b/tests/offset/shape_type_i_c/ZY7
@@ -4,4 +4,7 @@ OFFSETSHAPE 6 {} $calcul $type
 
 checkprops result -v 813077 -s 70451.1
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 14 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZY8 b/tests/offset/shape_type_i_c/ZY8
index d97a14107f..68eb376d60 100644
--- a/tests/offset/shape_type_i_c/ZY8
+++ b/tests/offset/shape_type_i_c/ZY8
@@ -5,4 +5,7 @@ OFFSETSHAPE 3 {} $calcul $type
 checkprops result -v 4422.98
 checkprops result -s 1736.95
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 14 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/offset/shape_type_i_c/ZZ1 b/tests/offset/shape_type_i_c/ZZ1
index afa9394e28..f235788aaf 100755
--- a/tests/offset/shape_type_i_c/ZZ1
+++ b/tests/offset/shape_type_i_c/ZZ1
@@ -1,6 +1,6 @@
-puts "TODO CR27414 ALL: Error : The area of result shape is"
-puts "TODO CR27414 ALL: Error : The volume of result shape is"
-puts "TODO CR27414 ALL: is not equal to zero"
+puts "TODO OCC27414 ALL: Error: The command cannot be built"
+puts "TODO OCC27414 ALL: gives an empty result"
+puts "TODO OCC27414 ALL: TEST INCOMPLETE"
 
 restore [locate_data_file bug26917_input_segfault.brep] s
 
diff --git a/tests/offset/shape_type_i_c/ZZ2 b/tests/offset/shape_type_i_c/ZZ2
index 40a461796c..728bad4a1b 100755
--- a/tests/offset/shape_type_i_c/ZZ2
+++ b/tests/offset/shape_type_i_c/ZZ2
@@ -1,13 +1,10 @@
-puts "TODO CR27414 ALL: Error : The area of result shape is"
-puts "TODO CR27414 ALL: Error : The volume of result shape is"
-puts "TODO CR27414 ALL: Error :  is WRONG because number of SHELL entities in shape"
-puts "TODO CR27414 ALL: is not equal to zero"
-
 restore [locate_data_file bug26917_offset_topology.brep] s
 
 OFFSETSHAPE 10 {} $calcul $type
 
-checkprops result -v 0
-checkprops result -s 0
+checkprops result -s 4.24638e+006 -v 2.9367e+008
 
-checknbshapes result -shell 1
+unifysamedom result_unif result
+checknbshapes result_unif -face 100 -shell 1
+
+checkview -display result_unif -2d -path ${imagedir}/${test_image}.png