From c60370656c3ff59732159cf2b12be992de1ebad8 Mon Sep 17 00:00:00 2001
From: pdn <pdn@opencascade.com>
Date: Thu, 16 Oct 2014 14:24:19 +0400
Subject: [PATCH] 0007570: Exception in ShapeFix_Wireframe::FixSmallEdges

Exception fixed by checking if subshape removed completely.

Test-case for issue #7570
---
 src/QABugs/QABugs_19.cxx            | 22 ++++++++++++++++++++++
 src/ShapeFix/ShapeFix_Wireframe.cxx | 15 ++++++++++-----
 tests/bugs/heal/bug7570             | 13 +++++++++++++
 3 files changed, 45 insertions(+), 5 deletions(-)
 create mode 100644 tests/bugs/heal/bug7570

diff --git a/src/QABugs/QABugs_19.cxx b/src/QABugs/QABugs_19.cxx
index 54aa72baef..24dbedd943 100755
--- a/src/QABugs/QABugs_19.cxx
+++ b/src/QABugs/QABugs_19.cxx
@@ -2861,6 +2861,27 @@ static Standard_Integer OCC25202 ( Draw_Interpretor& theDI,
   return 0;
 }
 
+#include <ShapeFix_Wireframe.hxx>
+//=======================================================================
+//function : OCC7570
+//purpose  : 
+//=======================================================================
+static Standard_Integer OCC7570 (Draw_Interpretor& di, Standard_Integer n, const char** a)
+{
+  if (n != 2) {
+    di<<"Usage: "<<a[0]<<" invalid number of arguments"<<"\n";
+    return 1;
+  }
+  TopoDS_Shape in_shape (DBRep::Get (a[1]));
+  ShapeFix_Wireframe fix_tool (in_shape);
+  fix_tool.ModeDropSmallEdges () = Standard_True;
+  fix_tool.SetPrecision (1.e+6);
+  fix_tool.SetLimitAngle (0.01);
+  fix_tool.FixSmallEdges ();
+  TopoDS_Shape new_shape = fix_tool.Shape ();
+  return 0;
+}
+
 /*****************************************************************************/
 
 void QABugs::Commands_19(Draw_Interpretor& theCommands) {
@@ -2918,5 +2939,6 @@ void QABugs::Commands_19(Draw_Interpretor& theCommands) {
   theCommands.Add ("OCC25043", "OCC25043 shape", __FILE__, OCC25043, group);
   theCommands.Add ("OCC24606", "OCC24606 : Tests ::FitAll for V3d view ('vfit' is for NIS view)", __FILE__, OCC24606, group);
   theCommands.Add ("OCC25202", "OCC25202 res shape numF1 face1 numF2 face2", __FILE__, OCC25202, group);
+  theCommands.Add ("OCC7570", "OCC7570 shape", __FILE__, OCC7570, group);
   return;
 }
diff --git a/src/ShapeFix/ShapeFix_Wireframe.cxx b/src/ShapeFix/ShapeFix_Wireframe.cxx
index 64fefdb8de..508d5470d6 100644
--- a/src/ShapeFix/ShapeFix_Wireframe.cxx
+++ b/src/ShapeFix/ShapeFix_Wireframe.cxx
@@ -426,16 +426,21 @@ ShapeFix_Wireframe::ShapeFix_Wireframe(const TopoDS_Shape& shape)
       TopoDS_Shape res;
       if ( cont.IsBound ( shape1 ) )
       {
-	res = cont.Find ( shape1 ).Oriented ( shape1.Orientation() );
+        res = cont.Find ( shape1 ).Oriented ( shape1.Orientation() );
       }
       else 
       {
-	myShape = shape1;
-	FixSmallEdges();
-	res = Shape();
-	cont.Bind(myShape,res);
+        myShape = shape1;
+        FixSmallEdges();
+        res = Shape();
+        cont.Bind(myShape,res);
       }
       if ( ! res.IsSame ( shape1 ) ) locModified = Standard_True;
+
+      //check if resulting shape if not empty
+      if( res.IsNull())
+        continue;
+
       res.Location ( L );
       B.Add ( C, res );
       
diff --git a/tests/bugs/heal/bug7570 b/tests/bugs/heal/bug7570
new file mode 100644
index 0000000000..01130d47a5
--- /dev/null
+++ b/tests/bugs/heal/bug7570
@@ -0,0 +1,13 @@
+puts "======="
+puts "OCC7570"
+puts "======="
+puts ""
+##################################################
+# Exception in ShapeFix_Wireframe::FixSmallEdges
+##################################################
+
+pload QAcommands
+
+restore [locate_data_file bug7570_small.brep] a
+
+OCC7570 a