From 20c367f2dc991ef6f947237fdc2acd3794a58309 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Fri, 27 Feb 2015 23:27:08 +0100
Subject: [PATCH] + in Fem constraint force dialog handle empty Direction

---
 src/Mod/Fem/App/FemConstraint.cpp      | 11 ++++++++++-
 src/Mod/Fem/App/FemConstraintForce.cpp |  7 +++++--
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/Mod/Fem/App/FemConstraint.cpp b/src/Mod/Fem/App/FemConstraint.cpp
index 1297b8fefb..565167ee45 100644
--- a/src/Mod/Fem/App/FemConstraint.cpp
+++ b/src/Mod/Fem/App/FemConstraint.cpp
@@ -55,6 +55,7 @@
 
 #include <Mod/Part/App/PartFeature.h>
 #include <Base/Console.h>
+#include <Base/Exception.h>
 
 using namespace Fem;
 
@@ -312,7 +313,15 @@ const Base::Vector3d Constraint::getDirection(const App::PropertyLinkSub &direct
     const Part::TopoShape& shape = feat->Shape.getShape();
     if (shape.isNull())
         return Base::Vector3d(0,0,0);
-    TopoDS_Shape sh = shape.getSubShape(subName.c_str());
+    TopoDS_Shape sh;
+    try {
+        sh = shape.getSubShape(subName.c_str());
+    }
+    catch (Standard_Failure) {
+        std::stringstream str;
+        str << "No such sub-element '" << subName << "'";
+        throw Base::AttributeError(str.str());
+    }
     gp_Dir dir;
 
     if (sh.ShapeType() == TopAbs_FACE) {
diff --git a/src/Mod/Fem/App/FemConstraintForce.cpp b/src/Mod/Fem/App/FemConstraintForce.cpp
index cca87225e6..3a30b1192d 100644
--- a/src/Mod/Fem/App/FemConstraintForce.cpp
+++ b/src/Mod/Fem/App/FemConstraintForce.cpp
@@ -96,8 +96,11 @@ void ConstraintForce::onChanged(const App::Property* prop)
     } else if (prop == &NormalDirection) {
         // Set a default direction if no direction reference has been given
         if (Direction.getValue() == NULL) {
-            DirectionVector.setValue(NormalDirection.getValue());
-            naturalDirectionVector = NormalDirection.getValue();
+            Base::Vector3d direction = NormalDirection.getValue();
+            if (Reversed.getValue())
+                direction = -direction;
+            DirectionVector.setValue(direction);
+            naturalDirectionVector = direction;
         }
     }
 }