diff --git a/src/IntPatch/IntPatch_ImpImpIntersection_4.gxx b/src/IntPatch/IntPatch_ImpImpIntersection_4.gxx
index 6812cd74d3..d5cdd429ca 100644
--- a/src/IntPatch/IntPatch_ImpImpIntersection_4.gxx
+++ b/src/IntPatch/IntPatch_ImpImpIntersection_4.gxx
@@ -1860,6 +1860,13 @@ Standard_Boolean IntCyCyTrim( const IntSurf_Quadric& theQuad1,
 
   //Getting Walking-line
 
+  enum WLFStatus
+  {
+    WLFStatus_Absent = 0,
+    WLFStatus_Exist  = 1,
+    WLFStatus_Broken = 2
+  };
+
   for(Standard_Integer aCurInterval = 0; aCurInterval < aNbOfBoundaries; aCurInterval++)
   {
     if(Precision::IsInfinite(aU1f[aCurInterval]) && Precision::IsInfinite(aU1l[aCurInterval]))
@@ -1878,7 +1885,7 @@ Standard_Boolean IntCyCyTrim( const IntSurf_Quadric& theQuad1,
     while(anUf < anUl)
     {
       Standard_Real aU2[aNbWLines], aV1[aNbWLines], aV2[aNbWLines];
-      Standard_Integer aWLFindStatus[aNbWLines];
+      WLFStatus aWLFindStatus[aNbWLines];
       Standard_Real aV1Prev[aNbWLines], aV2Prev[aNbWLines];
       Standard_Real anArccosFactor[aNbWLines] = {1.0, -1.0};
       Standard_Boolean isAddingWLEnabled[aNbWLines];
@@ -1889,7 +1896,7 @@ Standard_Boolean IntCyCyTrim( const IntSurf_Quadric& theQuad1,
       {
         aL2S[i] = new IntSurf_LineOn2S();
         aWLine[i] = new IntPatch_WLine(aL2S[i], Standard_False);
-        aWLFindStatus[i] = 0;
+        aWLFindStatus[i] = WLFStatus_Absent;
         isAddingWLEnabled[i] = Standard_True;
         aU2[i] = aV1[i] = aV2[i] = 0.0;
         aV1Prev[i] = aV2Prev[i] = 0.0;
@@ -1929,7 +1936,7 @@ Standard_Boolean IntCyCyTrim( const IntSurf_Quadric& theQuad1,
             anU1 = anU1crit[i];
 
             for(Standard_Integer i = 0; i < aNbWLines; i++)
-              aWLFindStatus[i] = 2;
+              aWLFindStatus[i] = WLFStatus_Broken;
 
             break;
           }
@@ -2005,6 +2012,18 @@ Standard_Boolean IntCyCyTrim( const IntSurf_Quadric& theQuad1,
             }
           }
 
+          if(aWLFindStatus[i] == WLFStatus_Broken)
+          {
+            if(Abs(aU2[i]) <= theTol2D)
+              aU2[i] = 0.0;
+            else if(Abs(aU2[i] - aPeriod) <= theTol2D)
+              aU2[i] = aPeriod;
+            else if(Abs(aU2[i] - aUSurf2f) <= theTol2D)
+              aU2[i] = aUSurf2f;
+            else if(Abs(aU2[i] - aUSurf2l) <= theTol2D)
+              aU2[i] = aUSurf2l;
+          }
+
           aV1[i] =  anEquationCoeffs.mK21 * sin(aU2[i]) + 
                     anEquationCoeffs.mK11 * sin(anU1) +
                     anEquationCoeffs.mL21 * cos(aU2[i]) +
@@ -2033,7 +2052,7 @@ Standard_Boolean IntCyCyTrim( const IntSurf_Quadric& theQuad1,
             aV1Prev[i] = aV1[i];
             aV2Prev[i] = aV2[i];
 
-            if(aWLFindStatus[i] == 2)
+            if(aWLFindStatus[i] == WLFStatus_Broken)
               isBroken = Standard_True;
 
             continue;
@@ -2044,7 +2063,7 @@ Standard_Boolean IntCyCyTrim( const IntSurf_Quadric& theQuad1,
               ((aVSurf2f - aV2[i]) <= theTol2D) && ((aV2[i] - aVSurf2l) <= theTol2D))
           {
             Standard_Boolean isForce = Standard_False;
-            if(!aWLFindStatus[i])
+            if(aWLFindStatus[i] == WLFStatus_Absent)
             {
               Standard_Boolean isFound1 = Standard_False, isFound2 = Standard_False;
 
@@ -2061,27 +2080,27 @@ Standard_Boolean IntCyCyTrim( const IntSurf_Quadric& theQuad1,
               
               if(isFound1 || isFound2)
               {
-                aWLFindStatus[i] = 1;
+                aWLFindStatus[i] = WLFStatus_Exist;
               }
             }
 
-            if(( aWLFindStatus[i] != 2) || (aWLine[i]->NbPnts() >= 1))
+            if(( aWLFindStatus[i] != WLFStatus_Broken) || (aWLine[i]->NbPnts() >= 1))
             {
               if(AddPointIntoWL(theQuad1, theQuad2, isTheReverse, 
                                 gp_Pnt2d(anU1, aV1[i]), gp_Pnt2d(aU2[i], aV2[i]),
                                 aUSurf1f, aUSurf1l, aPeriod,
                                 aWLine[i]->Curve(), theTol3D, theTol2D, isForce))
               {
-                if(!aWLFindStatus[i])
+                if(aWLFindStatus[i] == WLFStatus_Absent)
                 {
-                  aWLFindStatus[i] = 1;
+                  aWLFindStatus[i] = WLFStatus_Exist;
                 }
               }
             }
           }
           else
           {
-            if(aWLFindStatus[i] == 1)
+            if(aWLFindStatus[i] == WLFStatus_Exist)
             {
               Standard_Boolean isFound1 = Standard_False, isFound2 = Standard_False;
 
@@ -2092,14 +2111,14 @@ Standard_Boolean IntCyCyTrim( const IntSurf_Quadric& theQuad1,
                                 anArccosFactor[i], Standard_False, isFound1, isFound2);
 
               if(isFound1 || isFound2)
-                aWLFindStatus[i] = 2; //start a new line
+                aWLFindStatus[i] = WLFStatus_Broken; //start a new line
             }
           }
 
           aV1Prev[i] = aV1[i];
           aV2Prev[i] = aV2[i];
 
-          if(aWLFindStatus[i] == 2)
+          if(aWLFindStatus[i] == WLFStatus_Broken)
             isBroken = Standard_True;
         }//for(Standard_Integer i = 0; i < aNbWLines; i++)
 
@@ -2228,201 +2247,6 @@ Standard_Boolean IntCyCyTrim( const IntSurf_Quadric& theQuad1,
     }
   }
 
-  if(theSlin.Length() > 0)
-  {
-    for(Standard_Integer aNumOfLine = 2; aNumOfLine <= theSlin.Length(); aNumOfLine++)
-    {
-      const Handle(IntPatch_WLine)& aWLine = Handle(IntPatch_WLine)::DownCast(theSlin.Value(aNumOfLine));
-
-      const IntSurf_PntOn2S& aPntFWL = aWLine->Point(1);
-
-      Standard_Real aU1 = 0.0, aU2 = 0.0, aV1 = 0.0, aV2 = 0.0;
-      aPntFWL.Parameters(aU1, aV1, aU2, aV2);
-
-      if( IsEqual(aU1, 0.0) || IsEqual(aU1, aPeriod))
-      {
-        theSlin.Exchange(1, aNumOfLine);
-        break;
-      }
-    }
-
-    for(Standard_Integer aNumOfLine1 = 1; aNumOfLine1 <= theSlin.Length(); aNumOfLine1++)
-    {
-      const Handle(IntPatch_WLine)& aWLine1 = Handle(IntPatch_WLine)::DownCast(theSlin.Value(aNumOfLine1));
-
-      const Standard_Integer aNbPntsWL1 = aWLine1->NbPnts();
-      const IntSurf_PntOn2S& aPntFWL1 = aWLine1->Point(1);
-      const IntSurf_PntOn2S& aPntLWL1 = aWLine1->Point(aNbPntsWL1);
-
-      for(Standard_Integer aNPt = 1; aNPt <= theSPnt.Length(); aNPt++)
-      {
-        const IntSurf_PntOn2S aPntCur = theSPnt.Value(aNPt).PntOn2S();
-
-        if( aPntCur.IsSame(aPntFWL1, Precision::Confusion()) ||
-            aPntCur.IsSame(aPntLWL1, Precision::Confusion()))
-        {
-          theSPnt.Remove(aNPt);
-          aNPt--;
-        }
-      }
-
-      Standard_Boolean hasBeenRemoved = Standard_False;
-      for(Standard_Integer aNumOfLine2 = aNumOfLine1 + 1; aNumOfLine2 <= theSlin.Length(); aNumOfLine2++)
-      {
-        const Handle(IntPatch_WLine)& aWLine2 = Handle(IntPatch_WLine)::DownCast(theSlin.Value(aNumOfLine2));
-
-        const Standard_Integer aNbPntsWL1 = aWLine1->NbPnts();
-        const Standard_Integer aNbPntsWL2 = aWLine2->NbPnts();
-
-        const IntSurf_PntOn2S& aPntFWL1 = aWLine1->Point(1);
-        const IntSurf_PntOn2S& aPntLWL1 = aWLine1->Point(aNbPntsWL1);
-
-        const IntSurf_PntOn2S& aPntFWL2 = aWLine2->Point(1);
-        const IntSurf_PntOn2S& aPntLWL2 = aWLine2->Point(aNbPntsWL2);
-
-        if(aPntFWL1.IsSame(aPntFWL2, Precision::Confusion()))
-        {
-          Standard_Real aU11 = 0.0, aU12 = 0.0, aV11 = 0.0, aV12 = 0.0;
-          Standard_Real aU21 = 0.0, aU22 = 0.0, aV21 = 0.0, aV22 = 0.0;
-
-          aPntFWL1.Parameters(aU11, aV11, aU12, aV12);
-          aPntFWL2.Parameters(aU21, aV21, aU22, aV22);
-
-          if( !(IsEqual(fmod(aU11, aPeriod), 0.0) ||
-                IsEqual(fmod(aU12, aPeriod), 0.0) ||
-                IsEqual(fmod(aU21, aPeriod), 0.0) ||
-                IsEqual(fmod(aU22, aPeriod), 0.0) ||
-                IsEqual(aU11, aUSurf1f) || IsEqual(aU11, aUSurf1l) ||
-                IsEqual(aU21, aUSurf1f) || IsEqual(aU21, aUSurf1l) ||
-                IsEqual(aU12, aUSurf2f) || IsEqual(aU12, aUSurf2l) ||
-                IsEqual(aU22, aUSurf2f) || IsEqual(aU22, aUSurf2l)))
-          {
-            aWLine1->ClearVertexes();
-            for(Standard_Integer aNPt = 1; aNPt <= aNbPntsWL2; aNPt++)
-            {
-              const IntSurf_PntOn2S& aPt = aWLine2->Point(aNPt);
-              aWLine1->Curve()->InsertBefore(1, aPt);
-            }
-
-            aWLine1->ComputeVertexParameters(theTol3D);
-
-            theSlin.Remove(aNumOfLine2);
-            aNumOfLine2--;
-            hasBeenRemoved = Standard_True;
-
-            continue;
-          }
-        }
-
-        if(aPntFWL1.IsSame(aPntLWL2, Precision::Confusion()))
-        {
-          Standard_Real aU11 = 0.0, aU12 = 0.0, aV11 = 0.0, aV12 = 0.0;
-          Standard_Real aU21 = 0.0, aU22 = 0.0, aV21 = 0.0, aV22 = 0.0;
-
-          aPntFWL1.Parameters(aU11, aV11, aU12, aV12);
-          aPntLWL2.Parameters(aU21, aV21, aU22, aV22);
-
-          if( !(IsEqual(fmod(aU11, aPeriod), 0.0) ||
-                IsEqual(fmod(aU12, aPeriod), 0.0) ||
-                IsEqual(fmod(aU21, aPeriod), 0.0) ||
-                IsEqual(fmod(aU22, aPeriod), 0.0) ||
-                IsEqual(aU11, aUSurf1f) || IsEqual(aU11, aUSurf1l) ||
-                IsEqual(aU21, aUSurf1f) || IsEqual(aU21, aUSurf1l) ||
-                IsEqual(aU12, aUSurf2f) || IsEqual(aU12, aUSurf2l) ||
-                IsEqual(aU22, aUSurf2f) || IsEqual(aU22, aUSurf2l)))
-          {
-            aWLine1->ClearVertexes();
-            for(Standard_Integer aNPt = aNbPntsWL2; aNPt >= 1; aNPt--)
-            {
-              const IntSurf_PntOn2S& aPt = aWLine2->Point(aNPt);
-              aWLine1->Curve()->InsertBefore(1, aPt);
-            }
-
-            aWLine1->ComputeVertexParameters(theTol3D);
-
-            theSlin.Remove(aNumOfLine2);
-            aNumOfLine2--;
-            hasBeenRemoved = Standard_True;
-
-            continue;
-          }
-        }
-
-        if(aPntLWL1.IsSame(aPntFWL2, Precision::Confusion()))
-        {
-          Standard_Real aU11 = 0.0, aU12 = 0.0, aV11 = 0.0, aV12 = 0.0;
-          Standard_Real aU21 = 0.0, aU22 = 0.0, aV21 = 0.0, aV22 = 0.0;
-
-          aPntLWL1.Parameters(aU11, aV11, aU12, aV12);
-          aPntFWL2.Parameters(aU21, aV21, aU22, aV22);
-
-          if( !(IsEqual(fmod(aU11, aPeriod), 0.0) ||
-                IsEqual(fmod(aU12, aPeriod), 0.0) ||
-                IsEqual(fmod(aU21, aPeriod), 0.0) ||
-                IsEqual(fmod(aU22, aPeriod), 0.0) ||
-                IsEqual(aU11, aUSurf1f) || IsEqual(aU11, aUSurf1l) ||
-                IsEqual(aU21, aUSurf1f) || IsEqual(aU21, aUSurf1l) ||
-                IsEqual(aU12, aUSurf2f) || IsEqual(aU12, aUSurf2l) ||
-                IsEqual(aU22, aUSurf2f) || IsEqual(aU22, aUSurf2l)))
-          {
-            aWLine1->ClearVertexes();
-            for(Standard_Integer aNPt = 1; aNPt <= aNbPntsWL2; aNPt++)
-            {
-              const IntSurf_PntOn2S& aPt = aWLine2->Point(aNPt);
-              aWLine1->Curve()->Add(aPt);
-            }
-
-            aWLine1->ComputeVertexParameters(theTol3D);
-
-            theSlin.Remove(aNumOfLine2);
-            aNumOfLine2--;
-            hasBeenRemoved = Standard_True;
-
-            continue;
-          }
-        }
-
-        if(aPntLWL1.IsSame(aPntLWL2, Precision::Confusion()))
-        {
-          Standard_Real aU11 = 0.0, aU12 = 0.0, aV11 = 0.0, aV12 = 0.0;
-          Standard_Real aU21 = 0.0, aU22 = 0.0, aV21 = 0.0, aV22 = 0.0;
-
-          aPntLWL1.Parameters(aU11, aV11, aU12, aV12);
-          aPntLWL2.Parameters(aU21, aV21, aU22, aV22);
-
-          if( !(IsEqual(fmod(aU11, aPeriod), 0.0) ||
-                IsEqual(fmod(aU12, aPeriod), 0.0) ||
-                IsEqual(fmod(aU21, aPeriod), 0.0) ||
-                IsEqual(fmod(aU22, aPeriod), 0.0) ||
-                IsEqual(aU11, aUSurf1f) || IsEqual(aU11, aUSurf1l) ||
-                IsEqual(aU21, aUSurf1f) || IsEqual(aU21, aUSurf1l) ||
-                IsEqual(aU12, aUSurf2f) || IsEqual(aU12, aUSurf2l) ||
-                IsEqual(aU22, aUSurf2f) || IsEqual(aU22, aUSurf2l)))
-          {
-            aWLine1->ClearVertexes();
-            for(Standard_Integer aNPt = aNbPntsWL2; aNPt >= 1; aNPt--)
-            {
-              const IntSurf_PntOn2S& aPt = aWLine2->Point(aNPt);
-              aWLine1->Curve()->Add(aPt);
-            }
-
-            aWLine1->ComputeVertexParameters(theTol3D);
-
-            theSlin.Remove(aNumOfLine2);
-            aNumOfLine2--;
-            hasBeenRemoved = Standard_True;
-
-            continue;
-          }
-        }
-      }
-
-      if(hasBeenRemoved)
-        aNumOfLine1--;
-    }
-  }//if(theSlin.Length() > 0)
-
-
   return Standard_True;
 }
 
diff --git a/src/IntPatch/IntPatch_Intersection.cxx b/src/IntPatch/IntPatch_Intersection.cxx
index 3698adde4c..dee76ad1fb 100644
--- a/src/IntPatch/IntPatch_Intersection.cxx
+++ b/src/IntPatch/IntPatch_Intersection.cxx
@@ -29,6 +29,220 @@
 #define DEBUG 0 
 static const Standard_Integer aNbPointsInALine = 200;
 
+//=======================================================================
+//function : IsSeamOrBound
+//purpose  : Returns TRUE if point thePt1 lies in seam-edge
+//            (if it exists) or surface boundaries;
+//=======================================================================
+static Standard_Boolean IsSeamOrBound(const IntSurf_PntOn2S& thePt1,
+                                      const Standard_Real theU1Period,
+                                      const Standard_Real theU2Period,
+                                      const Standard_Real theV1Period,
+                                      const Standard_Real theV2Period,
+                                      const Standard_Real theUfSurf1,
+                                      const Standard_Real theUlSurf1,
+                                      const Standard_Real theVfSurf1,
+                                      const Standard_Real theVlSurf1,
+                                      const Standard_Real theUfSurf2,
+                                      const Standard_Real theUlSurf2,
+                                      const Standard_Real theVfSurf2,
+                                      const Standard_Real theVlSurf2)
+{
+  Standard_Real aU11 = 0.0, aU12 = 0.0, aV11 = 0.0, aV12 = 0.0;
+  thePt1.Parameters(aU11, aV11, aU12, aV12);
+
+  Standard_Boolean aCond = Standard_False;
+  aCond = aCond || (!IsEqual(theU1Period, 0.0) &&
+                    IsEqual(fmod(aU11, theU1Period), 0.0));
+
+  aCond = aCond || (!IsEqual(theU2Period, 0.0) &&
+                    IsEqual(fmod(aU12, theU2Period), 0.0));
+
+  aCond = aCond || (!IsEqual(theV1Period, 0.0) &&
+                    IsEqual(fmod(aV11, theV1Period), 0.0));
+
+  aCond = aCond || (!IsEqual(theV2Period, 0.0) &&
+                    IsEqual(fmod(aV12, theV2Period), 0.0));
+
+  return  aCond ||
+          IsEqual(aU11, theUfSurf1) || IsEqual(aU11, theUlSurf1) ||
+          IsEqual(aU12, theUfSurf2) || IsEqual(aU12, theUlSurf2) ||
+          IsEqual(aV11, theVfSurf1) || IsEqual(aV11, theVlSurf1) ||
+          IsEqual(aV12, theVfSurf2) || IsEqual(aV12, theVlSurf2);
+}
+
+//=======================================================================
+//function : JoinWLines
+//purpose  : joins all WLines from theSlin to one if it is possible and
+//            records the result into theSlin again.
+//            Lines will be kept to be splitted if:
+//              a) they are separated (has no common points);
+//              b) resulted line (after joining) go through
+//                 seam-edges or surface boundaries.
+//
+//          In addition, if points in theSPnt lies at least in one of 
+//          the line in theSlin, this point will be deleted.
+//=======================================================================
+static void JoinWLines(IntPatch_SequenceOfLine& theSlin,
+                IntPatch_SequenceOfPoint& theSPnt,
+                const Standard_Real theTol3D,
+                const Standard_Real theU1Period,
+                const Standard_Real theU2Period,
+                const Standard_Real theV1Period,
+                const Standard_Real theV2Period,
+                const Standard_Real theUfSurf1,
+                const Standard_Real theUlSurf1,
+                const Standard_Real theVfSurf1,
+                const Standard_Real theVlSurf1,
+                const Standard_Real theUfSurf2,
+                const Standard_Real theUlSurf2,
+                const Standard_Real theVfSurf2,
+                const Standard_Real theVlSurf2)
+{
+  if(theSlin.Length() == 0)
+    return;
+
+  for(Standard_Integer aNumOfLine1 = 1; aNumOfLine1 <= theSlin.Length(); aNumOfLine1++)
+  {
+    const Handle(IntPatch_WLine)& aWLine1 = Handle(IntPatch_WLine)::DownCast(theSlin.Value(aNumOfLine1));
+
+    if(aWLine1.IsNull())
+    {//We must have failure to join not-point-lines
+      return;
+    }
+
+    const Standard_Integer aNbPntsWL1 = aWLine1->NbPnts();
+    const IntSurf_PntOn2S& aPntFWL1 = aWLine1->Point(1);
+    const IntSurf_PntOn2S& aPntLWL1 = aWLine1->Point(aNbPntsWL1);
+
+    for(Standard_Integer aNPt = 1; aNPt <= theSPnt.Length(); aNPt++)
+    {
+      const IntSurf_PntOn2S aPntCur = theSPnt.Value(aNPt).PntOn2S();
+
+      if( aPntCur.IsSame(aPntFWL1, Precision::Confusion()) ||
+        aPntCur.IsSame(aPntLWL1, Precision::Confusion()))
+      {
+        theSPnt.Remove(aNPt);
+        aNPt--;
+      }
+    }
+
+    Standard_Boolean hasBeenRemoved = Standard_False;
+    for(Standard_Integer aNumOfLine2 = aNumOfLine1 + 1; aNumOfLine2 <= theSlin.Length(); aNumOfLine2++)
+    {
+      const Handle(IntPatch_WLine)& aWLine2 = Handle(IntPatch_WLine)::DownCast(theSlin.Value(aNumOfLine2));
+
+      const Standard_Integer aNbPntsWL1 = aWLine1->NbPnts();
+      const Standard_Integer aNbPntsWL2 = aWLine2->NbPnts();
+
+      const IntSurf_PntOn2S& aPntFWL1 = aWLine1->Point(1);
+      const IntSurf_PntOn2S& aPntLWL1 = aWLine1->Point(aNbPntsWL1);
+
+      const IntSurf_PntOn2S& aPntFWL2 = aWLine2->Point(1);
+      const IntSurf_PntOn2S& aPntLWL2 = aWLine2->Point(aNbPntsWL2);
+
+      if(aPntFWL1.IsSame(aPntFWL2, Precision::Confusion()))
+      {
+        if(!IsSeamOrBound(aPntFWL1, theU1Period, theU2Period,
+                          theV1Period, theV2Period, theUfSurf1, theUlSurf1,
+                          theVfSurf1, theVlSurf1, theUfSurf2, theUlSurf2,
+                          theVfSurf2, theVlSurf2))
+        {
+          aWLine1->ClearVertexes();
+          for(Standard_Integer aNPt = 1; aNPt <= aNbPntsWL2; aNPt++)
+          {
+            const IntSurf_PntOn2S& aPt = aWLine2->Point(aNPt);
+            aWLine1->Curve()->InsertBefore(1, aPt);
+          }
+
+          aWLine1->ComputeVertexParameters(theTol3D);
+
+          theSlin.Remove(aNumOfLine2);
+          aNumOfLine2--;
+          hasBeenRemoved = Standard_True;
+
+          continue;
+        }
+      }
+
+      if(aPntFWL1.IsSame(aPntLWL2, Precision::Confusion()))
+      {
+        if(!IsSeamOrBound(aPntFWL1, theU1Period, theU2Period,
+                          theV1Period, theV2Period, theUfSurf1, theUlSurf1,
+                          theVfSurf1, theVlSurf1, theUfSurf2, theUlSurf2,
+                          theVfSurf2, theVlSurf2))
+        {
+          aWLine1->ClearVertexes();
+          for(Standard_Integer aNPt = aNbPntsWL2; aNPt >= 1; aNPt--)
+          {
+            const IntSurf_PntOn2S& aPt = aWLine2->Point(aNPt);
+            aWLine1->Curve()->InsertBefore(1, aPt);
+          }
+
+          aWLine1->ComputeVertexParameters(theTol3D);
+
+          theSlin.Remove(aNumOfLine2);
+          aNumOfLine2--;
+          hasBeenRemoved = Standard_True;
+
+          continue;
+        }
+      }
+
+      if(aPntLWL1.IsSame(aPntFWL2, Precision::Confusion()))
+      {
+        if(!IsSeamOrBound(aPntLWL1, theU1Period, theU2Period,
+                          theV1Period, theV2Period, theUfSurf1, theUlSurf1,
+                          theVfSurf1, theVlSurf1, theUfSurf2, theUlSurf2,
+                          theVfSurf2, theVlSurf2))
+        {
+          aWLine1->ClearVertexes();
+          for(Standard_Integer aNPt = 1; aNPt <= aNbPntsWL2; aNPt++)
+          {
+            const IntSurf_PntOn2S& aPt = aWLine2->Point(aNPt);
+            aWLine1->Curve()->Add(aPt);
+          }
+
+          aWLine1->ComputeVertexParameters(theTol3D);
+
+          theSlin.Remove(aNumOfLine2);
+          aNumOfLine2--;
+          hasBeenRemoved = Standard_True;
+
+          continue;
+        }
+      }
+
+      if(aPntLWL1.IsSame(aPntLWL2, Precision::Confusion()))
+      {
+        if(!IsSeamOrBound(aPntLWL1, theU1Period, theU2Period,
+                          theV1Period, theV2Period, theUfSurf1, theUlSurf1,
+                          theVfSurf1, theVlSurf1, theUfSurf2, theUlSurf2,
+                          theVfSurf2, theVlSurf2))
+        {
+          aWLine1->ClearVertexes();
+          for(Standard_Integer aNPt = aNbPntsWL2; aNPt >= 1; aNPt--)
+          {
+            const IntSurf_PntOn2S& aPt = aWLine2->Point(aNPt);
+            aWLine1->Curve()->Add(aPt);
+          }
+
+          aWLine1->ComputeVertexParameters(theTol3D);
+
+          theSlin.Remove(aNumOfLine2);
+          aNumOfLine2--;
+          hasBeenRemoved = Standard_True;
+
+          continue;
+        }
+      }
+    }
+
+    if(hasBeenRemoved)
+      aNumOfLine1--;
+  }
+}
+
 //======================================================================
 // function: SequenceOfLine
 //======================================================================
@@ -1513,6 +1727,16 @@ void IntPatch_Intersection::
           const IntPatch_Point& aPoint = anInt.Point(aPID);
           spnt.Append(aPoint);
         }
+
+        JoinWLines( slin, spnt, theTolTang,
+                    theS1->IsUPeriodic()? theS1->UPeriod() : 0.0,
+                    theS2->IsUPeriodic()? theS2->UPeriod() : 0.0,
+                    theS1->IsVPeriodic()? theS1->VPeriod() : 0.0,
+                    theS2->IsVPeriodic()? theS2->VPeriod() : 0.0,
+                    theS1->FirstUParameter(), theS1->LastUParameter(),
+                    theS1->FirstVParameter(), theS1->LastVParameter(),
+                    theS2->FirstUParameter(), theS2->LastUParameter(),
+                    theS2->FirstVParameter(), theS2->LastVParameter());
       }
     }
   }
diff --git a/src/IntTools/IntTools_FaceFace.cxx b/src/IntTools/IntTools_FaceFace.cxx
index a06269587c..0bcbc42bee 100644
--- a/src/IntTools/IntTools_FaceFace.cxx
+++ b/src/IntTools/IntTools_FaceFace.cxx
@@ -3770,7 +3770,7 @@ Standard_Boolean DecompositionOfWLine(const Handle(IntPatch_WLine)& theWLine,
               bCheckAngle1 = Standard_True;
               aNewVec = gp_Vec2d(gp_Pnt2d(nU1, nV1), gp_Pnt2d(anewU, anewV));
 
-              if(aNewVec.SquareMagnitude() < (gp::Resolution() * gp::Resolution())) {
+              if(aNewVec.SquareMagnitude() < gp::Resolution()) {
                 aNewP.SetValue((surfit == 0), anewU, anewV);
                 bCheckAngle1 = Standard_False;
               }
@@ -3779,7 +3779,7 @@ Standard_Boolean DecompositionOfWLine(const Handle(IntPatch_WLine)& theWLine,
               bCheckAngle2 = Standard_True;
               aNewVec = gp_Vec2d(gp_Pnt2d(nU1, nV1), gp_Pnt2d(U, V));
 
-              if(aNewVec.SquareMagnitude() < (gp::Resolution() * gp::Resolution())) {
+              if(aNewVec.SquareMagnitude() < gp::Resolution()) {
                 bCheckAngle2 = Standard_False;
               }
             }
@@ -3799,7 +3799,7 @@ Standard_Boolean DecompositionOfWLine(const Handle(IntPatch_WLine)& theWLine,
                   aPrevNeighbourPoint.ParametersOnS2(nU2, nV2);
                 gp_Vec2d aVecOld(gp_Pnt2d(nU2, nV2), gp_Pnt2d(nU1, nV1));
 
-                if(aVecOld.SquareMagnitude() <= (gp::Resolution() * gp::Resolution())) {
+                if(aVecOld.SquareMagnitude() <= gp::Resolution()) {
                   continue;
                 }
                 else {
@@ -3916,7 +3916,7 @@ Standard_Boolean DecompositionOfWLine(const Handle(IntPatch_WLine)& theWLine,
               ap2.SetX(nU2);
               ap2.SetY(nV2);
 
-              if(ap1.SquareDistance(ap2) > (gp::Resolution() * gp::Resolution())) {
+              if(ap1.SquareDistance(ap2) > gp::Resolution()) {
                 break;
               }
             }  
diff --git a/tests/bugs/modalg_5/bug24825_common b/tests/bugs/modalg_5/bug24825_common
index d66bc41dc6..25737d3ddf 100644
--- a/tests/bugs/modalg_5/bug24825_common
+++ b/tests/bugs/modalg_5/bug24825_common
@@ -45,14 +45,14 @@ bbop result 0
 
 set square 10008.9
 
-set nb_v_good 140
-set nb_e_good 186
+set nb_v_good 86
+set nb_e_good 132
 set nb_w_good 126
 set nb_f_good 126
 set nb_sh_good 40
 set nb_sol_good 40
 set nb_compsol_good 0
 set nb_compound_good 1
-set nb_shape_good 659
+set nb_shape_good 551
 
 set 2dviewer 1
diff --git a/tests/bugs/modalg_5/bug24825_cut b/tests/bugs/modalg_5/bug24825_cut
index a36b052b1f..4b404481fe 100644
--- a/tests/bugs/modalg_5/bug24825_cut
+++ b/tests/bugs/modalg_5/bug24825_cut
@@ -45,14 +45,14 @@ bbop result 2
 
 set square 103838
 
-set nb_v_good 160
-set nb_e_good 218
+set nb_v_good 106
+set nb_e_good 164
 set nb_w_good 142
 set nb_f_good 80
 set nb_sh_good 3
 set nb_sol_good 3
 set nb_compsol_good 0
 set nb_compound_good 1
-set nb_shape_good 607
+set nb_shape_good 499
 
 set 2dviewer 1
diff --git a/tests/bugs/modalg_5/bug24825_fuse b/tests/bugs/modalg_5/bug24825_fuse
index f9ce0fdfa5..a3f9aad3d7 100644
--- a/tests/bugs/modalg_5/bug24825_fuse
+++ b/tests/bugs/modalg_5/bug24825_fuse
@@ -46,14 +46,14 @@ bbop result 1
 
 set square 157211
 
-set nb_v_good 160
-set nb_e_good 218
+set nb_v_good 106
+set nb_e_good 164
 set nb_w_good 142
 set nb_f_good 80
 set nb_sh_good 1
 set nb_sol_good 1
 set nb_compsol_good 0
 set nb_compound_good 1
-set nb_shape_good 603
+set nb_shape_good 495
 
 set 2dviewer 1
diff --git a/tests/bugs/modalg_5/bug24981 b/tests/bugs/modalg_5/bug24981
index 42daa4eea3..3bfa8f1954 100644
--- a/tests/bugs/modalg_5/bug24981
+++ b/tests/bugs/modalg_5/bug24981
@@ -20,14 +20,14 @@ baddtools b_1 b_2 b_3 b_4 b_5 b_6 b_7 b_8 b_9 b_10 b_11 b_12 b_13 b_14 b_15 b_16
 bfillds
 bbuild result
 
-set nb_v_good 170
-set nb_e_good 268
+set nb_v_good 122
+set nb_e_good 220
 set nb_w_good 243
 set nb_f_good 195
 set nb_sh_good 75
 set nb_sol_good 75
 set nb_compsol_good 0
 set nb_compound_good  1
-set nb_shape_good 1027
+set nb_shape_good 931
 
 set 2dviewer 1
diff --git a/tests/bugs/modalg_5/bug25715_1 b/tests/bugs/modalg_5/bug25715_1
new file mode 100644
index 0000000000..3c98421a82
--- /dev/null
+++ b/tests/bugs/modalg_5/bug25715_1
@@ -0,0 +1,28 @@
+puts "=========="
+puts "OCC25715"
+puts "=========="
+puts ""
+#############################################################
+# Intersection between cylinders produces excess vertices
+#############################################################
+# don't change nbshapes values according to 25715
+
+pcylinder s1 0.069 0.6
+pcylinder s2 0.024, 0.4
+trotate s1 0 0 0 0 0 1 90
+trotate s2 0 0 0 0 1 0 90
+trotate s2 0 0 0 1 0 0 -45
+ttranslate s2 -0.2 0 0.48
+bcut result s1 s2
+
+set nb_v_good 4
+set nb_e_good 6
+set nb_w_good 6
+set nb_f_good 4
+set nb_sh_good 1
+set nb_sol_good 1
+set nb_compsol_good 0
+set nb_compound_good 1
+set nb_shape_good 23
+
+set 2dviewer 1
diff --git a/tests/bugs/modalg_5/bug25715_2 b/tests/bugs/modalg_5/bug25715_2
new file mode 100644
index 0000000000..898464fcd8
--- /dev/null
+++ b/tests/bugs/modalg_5/bug25715_2
@@ -0,0 +1,24 @@
+puts "=========="
+puts "OCC25715"
+puts "=========="
+puts ""
+#############################################################
+# Intersection between cylinders produces excess vertices
+#############################################################
+# don't change nbshapes values according to 25715
+
+restore [locate_data_file bug25715_b14p9s1.brep] s1
+restore [locate_data_file bug25715_b14p9s2.brep] s2
+bfuse result s1 s2
+
+set nb_v_good 4
+set nb_e_good 6
+set nb_w_good 6
+set nb_f_good 5
+set nb_sh_good 1
+set nb_sol_good 1
+set nb_compsol_good 0
+set nb_compound_good 1
+set nb_shape_good 24
+
+set 2dviewer 1
diff --git a/tests/bugs/modalg_5/bug25715_3 b/tests/bugs/modalg_5/bug25715_3
new file mode 100644
index 0000000000..47aab08c39
--- /dev/null
+++ b/tests/bugs/modalg_5/bug25715_3
@@ -0,0 +1,25 @@
+puts "TODO OCC24418 ALL: Error : Result shape is WRONG because it must contains"
+puts "=========="
+puts "OCC25715"
+puts "=========="
+puts ""
+#############################################################
+# Intersection between cylinders produces excess vertices
+#############################################################
+# don't change nbshapes values according to 25715
+
+restore [locate_data_file bug25715_p02c3s1.brep] s1
+restore [locate_data_file bug25715_p02c3s3.brep] s3
+bfuse result s1 s3
+
+set nb_v_good 8
+set nb_e_good 14
+set nb_w_good 6
+set nb_f_good 5
+set nb_sh_good 1
+set nb_sol_good 1
+set nb_compsol_good 0
+set nb_compound_good 1
+set nb_shape_good 36
+
+set 2dviewer 1