From 17fe63598f6dffac54bf87a336ce4c909be415ec Mon Sep 17 00:00:00 2001
From: WandererFan <wandererfan@gmail.com>
Date: Wed, 7 Sep 2016 15:41:35 -0400
Subject: [PATCH] Handle case where no faces found in View.

---
 src/Mod/TechDraw/App/EdgeWalker.cpp | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/Mod/TechDraw/App/EdgeWalker.cpp b/src/Mod/TechDraw/App/EdgeWalker.cpp
index 757a558fd..3db76fceb 100644
--- a/src/Mod/TechDraw/App/EdgeWalker.cpp
+++ b/src/Mod/TechDraw/App/EdgeWalker.cpp
@@ -155,10 +155,13 @@ ewWireList EdgeWalker::getResult()
 
 std::vector<TopoDS_Wire> EdgeWalker::getResultWires()
 {
+    std::vector<TopoDS_Wire> fw;
     ewWireList result = m_eV.getResult();
+    if (result.wires.empty()) {
+        return fw;
+    }
 
     std::vector<ewWire>::iterator iWire = result.wires.begin();     // a WE within [WE]
-    std::vector<TopoDS_Wire> fw;
     for (;iWire != result.wires.end(); iWire++) {
         std::vector<WalkerEdge>::iterator iEdge = (*iWire).wedges.begin();
         std::vector<TopoDS_Edge> topoEdges;
@@ -174,11 +177,14 @@ std::vector<TopoDS_Wire> EdgeWalker::getResultWires()
 
 std::vector<TopoDS_Wire> EdgeWalker::getResultNoDups()
 {
+    std::vector<TopoDS_Wire> fw;
     ewWireList result = m_eV.getResult();
+    if (result.wires.empty()) {
+        return fw;
+    }
     result = result.removeDuplicates();
 
     std::vector<ewWire>::iterator iWire = result.wires.begin();
-    std::vector<TopoDS_Wire> fw;
     for (;iWire != result.wires.end(); iWire++) {
         std::vector<WalkerEdge>::iterator iEdge = (*iWire).wedges.begin();
         std::vector<TopoDS_Edge> topoEdges;
@@ -310,6 +316,9 @@ void ewWire::push_back(WalkerEdge w)
 ewWireList ewWireList::removeDuplicates()
 {
     ewWireList result;
+    if (wires.empty()) {
+        return result;
+    }
     result.push_back(*(wires.begin()));                //save the first ewWire
     std::vector<ewWire>::iterator iWire = (wires.begin()) + 1;    //starting with second
     for (; iWire != wires.end(); iWire++) {