grid_texture off by one

Former-commit-id: 564346995cfbd8df95a2e15050937b01e4f0405a

include/igl/viewer/Viewer.cpp

@@ -363,7 +363,9 @@ namespace viewer
                    Eigen::Vector3d(255.0/255.0,228.0/255.0,58.0/255.0),
                    Eigen::Vector3d(255.0/255.0,235.0/255.0,80.0/255.0));
     if (data.V_uv.rows() == 0)
+    {
       data.grid_texture();
+    }
 
     core.align_camera_center(data.V,data.F);
 

include/igl/viewer/ViewerData.cpp

@@ -393,6 +393,12 @@ IGL_INLINE void igl::viewer::ViewerData::uniform_colors(Eigen::Vector3d ambient,
 
 IGL_INLINE void igl::viewer::ViewerData::grid_texture()
 {
+  // Don't do anything for an empty mesh
+  if(V.rows() == 0)
+  {
+    V_uv.resize(V.rows(),2);
+    return;
+  }
   if (V_uv.rows() == 0)
   {
     V_uv = V.block(0, 0, V.rows(), 2);