From 0fba03f8167844d545e234272ab8525e6159b700 Mon Sep 17 00:00:00 2001
From: Nyall Dawson <nyall.dawson@gmail.com>
Date: Tue, 19 Sep 2017 13:45:03 +1000
Subject: [PATCH] Fix potential crash in QgsCircularString::vertexAngle

---
 src/core/geometry/qgscircularstring.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/core/geometry/qgscircularstring.cpp b/src/core/geometry/qgscircularstring.cpp
index 0b23e024fdb1..8397910ac049 100644
--- a/src/core/geometry/qgscircularstring.cpp
+++ b/src/core/geometry/qgscircularstring.cpp
@@ -893,6 +893,12 @@ void QgsCircularString::insertVertexBetween( int after, int before, int pointOnC
 
 double QgsCircularString::vertexAngle( QgsVertexId vId ) const
 {
+  if ( numPoints() < 3 )
+  {
+    //undefined
+    return 0.0;
+  }
+
   int before = vId.vertex - 1;
   int vertex = vId.vertex;
   int after = vId.vertex + 1;