--- misc/build/libvisio-0.0.17/src/lib/VSDXContentCollector.cpp	2012-06-16 13:41:40.583153038 +0200
+++ misc/libvisio-0.0.17/src/lib/VSDXContentCollector.cpp	2012-06-16 13:44:16.311155881 +0200
@@ -1131,14 +1131,16 @@
     if (x <= m_pageWidth && x >= 0)
       points[x] = y;
 
-    xmove = points.begin()->first;
-    ymove = points.begin()->second;
-    for (std::map<double, double>::iterator iter = points.begin(); iter != points.end(); ++iter)
-    {
-      if (iter->first != xmove || iter->second != ymove)
+    if (!points.empty()) {
+      xmove = points.begin()->first;
+      ymove = points.begin()->second;
+      for (std::map<double, double>::iterator iter = points.begin(); iter != points.end(); ++iter)
       {
-        xline = iter->first;
-        yline = iter->second;
+        if (iter->first != xmove || iter->second != ymove)
+        {
+          xline = iter->first;
+          yline = iter->second;
+        }
       }
     }
   }