0027822: Exception access violation is raised in BRepOffsetAPI_MakePipeShell during of build

New public method IsDone() is added to abstract class BRepFill_SectionLaw.

Test case bugs/modlag_6/bug27822 has been added

src/BRepFill/BRepFill_NSections.cxx

@@ -360,6 +360,7 @@ BRepFill_NSections::BRepFill_NSections(const TopTools_SequenceOfShape& S,
   }
   myParams = par;
   Init(par,Build);
+  myDone = Standard_True;
 }
 
 //=======================================================================
@@ -399,7 +400,10 @@ BRepFill_NSections::BRepFill_NSections(const TopTools_SequenceOfShape& S,
     VFirst = VF;
     VLast = VL;
     Init(P,Build);
+    myDone = Standard_True;
   }
+  else
+    myDone = Standard_False;
 }
 
 //=======================================================================

src/BRepFill/BRepFill_PipeShell.cxx

@@ -1143,6 +1143,8 @@ void BRepFill_PipeShell::Generated(const TopoDS_Shape&   theShape,
   }
 
   myStatus = myLocation->GetStatus();
+  if (!mySection->IsDone())
+    myStatus = GeomFill_PipeNotOk;
 }
 
 //=======================================================================

src/BRepFill/BRepFill_SectionLaw.cxx

@@ -78,6 +78,15 @@ Standard_Integer BRepFill_SectionLaw::NbLaw() const
   return vclosed;
 }
 
+//=======================================================================
+//function : IsDone
+//purpose  : 
+//=======================================================================
+ Standard_Boolean BRepFill_SectionLaw::IsDone() const
+{
+  return myDone;
+}
+
 //=======================================================================
 //function : Init
 //purpose  : Prepare the parsing of a wire

src/BRepFill/BRepFill_SectionLaw.hxx

@@ -54,6 +54,8 @@ public:
   
   Standard_EXPORT Standard_Boolean IsVClosed() const;
   
+  Standard_EXPORT Standard_Boolean IsDone() const;
+  
   //! Say if the input sahpe is a  vertex.
   Standard_EXPORT virtual Standard_Boolean IsVertex() const = 0;
   
@@ -82,6 +84,7 @@ protected:
   Handle(GeomFill_HArray1OfSectionLaw) myLaws;
   Standard_Boolean uclosed;
   Standard_Boolean vclosed;
+  Standard_Boolean myDone;
 
 
 private:

src/BRepFill/BRepFill_ShapeLaw.cxx

@@ -72,6 +72,7 @@ BRepFill_ShapeLaw::BRepFill_ShapeLaw(const TopoDS_Vertex& V,
     myLaws->ChangeValue(1) = 
       new (GeomFill_UniformSection)(TC);
   }
+  myDone = Standard_True;
 }
 
 //=======================================================================
@@ -88,6 +89,7 @@ BRepFill_ShapeLaw::BRepFill_ShapeLaw(const TopoDS_Wire& W,
 {
   TheLaw.Nullify();
   Init(Build);
+  myDone = Standard_True;
 }
 
 //=======================================================================
@@ -104,6 +106,7 @@ BRepFill_ShapeLaw::BRepFill_ShapeLaw(const TopoDS_Wire& W,
 {
   TheLaw = L;
   Init(Build);
+  myDone = Standard_True;
 }
 
 //=======================================================================

tests/bugs/modalg_6/bug27822

@@ -0,0 +1,27 @@
+puts "========"
+puts "OCC27822"
+puts "========"
+puts ""
+#######################################################################################
+# Exception access violation is raised in BRepOffsetAPI_MakePipeShell during of build
+#######################################################################################
+
+circle c1 0 100 80 30
+circle c2 0 30 130 30
+mkedge e1 c1
+mkedge e2 c2
+vertex v1 0 0 0
+vertex v2 0 1 0
+edge e3 v1 v2
+wire w1 e1
+wire w2 e2
+wire w3 e3
+mksweep w3
+addsweep w1
+addsweep w2
+
+if {[catch {buildsweep result}]} {
+  puts "OCC27822 is fixed."
+} else {
+  puts "ERROR: OCC27822 does not fixed correctly."
+}