From 7f0b39bec9aa01a1716d27e8c44c6acc245bef5a Mon Sep 17 00:00:00 2001
From: ika <ika@opencascade.com>
Date: Thu, 19 Mar 2015 15:43:17 +0300
Subject: [PATCH] 0025843: Wire containing degenerated edge is not written to
 IGES / STEP

add check for edges with null 2D and 3D curves for STEP,
for IGES problem exists only with wires, where non-invalid edge is only one, and it is not the last in wire(fixed).

Test case for issue CR25843
---
 src/BRepToIGES/BRepToIGES_BRWire.cxx          |  6 ++---
 .../TopoDSToStep_WireframeBuilder.cxx         | 14 +++++++++--
 tests/bugs/iges/bug25843_iges                 | 23 +++++++++++++++++++
 tests/bugs/step/bug25843_step                 | 23 +++++++++++++++++++
 4 files changed, 61 insertions(+), 5 deletions(-)
 create mode 100755 tests/bugs/iges/bug25843_iges
 create mode 100755 tests/bugs/step/bug25843_step

diff --git a/src/BRepToIGES/BRepToIGES_BRWire.cxx b/src/BRepToIGES/BRepToIGES_BRWire.cxx
index c08a959da6..39153cc20b 100644
--- a/src/BRepToIGES/BRepToIGES_BRWire.cxx
+++ b/src/BRepToIGES/BRepToIGES_BRWire.cxx
@@ -525,8 +525,8 @@ Handle(IGESData_IGESEntity) BRepToIGES_BRWire ::TransferWire
 	AddWarning(mywire, "an Edge is a null entity");
       }
       else {
-	ent = TransferEdge(E, Standard_False);
-	if (!ent.IsNull()) Seq->Append(ent);
+	      ent = TransferEdge(E, Standard_False);
+	      if (!ent.IsNull()) Seq->Append(ent);
       }
     }
   }
@@ -537,7 +537,7 @@ Handle(IGESData_IGESEntity) BRepToIGES_BRWire ::TransferWire
   Standard_Integer nbedges = Seq->Length();
   Handle(IGESData_HArray1OfIGESEntity) Tab;
   if ( nbedges == 1 ) {
-    res = ent;
+    res = GetCasted(IGESData_IGESEntity, Seq->Value(1));
   }
   else if ( nbedges >= 2) {
     Tab =  new IGESData_HArray1OfIGESEntity(1,nbedges);
diff --git a/src/TopoDSToStep/TopoDSToStep_WireframeBuilder.cxx b/src/TopoDSToStep/TopoDSToStep_WireframeBuilder.cxx
index 8cb10cdb78..ae41d0ee42 100644
--- a/src/TopoDSToStep/TopoDSToStep_WireframeBuilder.cxx
+++ b/src/TopoDSToStep/TopoDSToStep_WireframeBuilder.cxx
@@ -54,6 +54,9 @@
 #include <TopExp_Explorer.hxx>
 #include <TopLoc_Location.hxx>
 
+#include <Standard_ErrorHandler.hxx>
+#include <Standard_NullObject.hxx>
+
 #include <StepGeom_CartesianPoint.hxx>
 #include <StepGeom_Curve.hxx>
 #include <StepGeom_SurfaceCurve.hxx>
@@ -178,8 +181,15 @@ Standard_Boolean TopoDSToStep_WireframeBuilder::
 //??    curveList->Append(Gpms);
     return Standard_True;
   }
-    
-  BRepAdaptor_Curve CA ( anEdge );
+
+  BRepAdaptor_Curve CA;
+  try {
+    OCC_CATCH_SIGNALS
+    CA.Initialize (anEdge);
+  }
+  catch (Standard_NullObject) {
+    return Standard_False;
+  }
 
   // Vertices
   TopoDS_Vertex Vfirst, Vlast;
diff --git a/tests/bugs/iges/bug25843_iges b/tests/bugs/iges/bug25843_iges
new file mode 100755
index 0000000000..975cc04f1c
--- /dev/null
+++ b/tests/bugs/iges/bug25843_iges
@@ -0,0 +1,23 @@
+puts "============"
+puts "OCC25843"
+puts "============"
+puts ""
+#######################################################################
+# Wire containing degenerated edge is not written to IGES / STEP
+#######################################################################
+
+restore [locate_data_file bug25843_onewire.brep] w
+
+set aFile ${imagedir}/bug25843_onewire.igs
+
+file delete ${aFile}
+
+brepiges w ${aFile}
+
+if { ![file exists ${aFile}] } {
+   puts "Error: Wire containing degenerated edge is not written to IGES file"
+} else {
+   puts "OK: Wire containing degenerated edge is written to IGES file"
+}
+
+catch {exec chmod 777 ${aFile}}
diff --git a/tests/bugs/step/bug25843_step b/tests/bugs/step/bug25843_step
new file mode 100755
index 0000000000..73cb424d1c
--- /dev/null
+++ b/tests/bugs/step/bug25843_step
@@ -0,0 +1,23 @@
+puts "============"
+puts "OCC25843"
+puts "============"
+puts ""
+#######################################################################
+# Wire containing degenerated edge is not written to IGES / STEP
+#######################################################################
+
+restore [locate_data_file bug25843_onewire.brep] w
+
+set aFile ${imagedir}/bug25843_onewire.stp
+
+catch { file delete ${aFile} }
+
+stepwrite 0 w ${aFile}
+
+if { ![file exists ${aFile}] } {
+   puts "Error: Wire containing degenerated edge is not written to STEP file"
+} else {
+   puts "OK: Wire containing degenerated edge is written to STEP file"
+}
+
+catch {exec chmod 777 ${aFile}}