From b1e4a5b823a9735f9c5b7645f82dc3b29dc2e474 Mon Sep 17 00:00:00 2001
From: Jukka Aho <jukka.aho@kapsi.fi>
Date: Thu, 31 Dec 2015 12:35:33 +0200
Subject: [PATCH] skip elements without master elements defined

---
 src/mortar.jl | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/mortar.jl b/src/mortar.jl
index b9ecc55..2f04ee1 100644
--- a/src/mortar.jl
+++ b/src/mortar.jl
@@ -678,6 +678,9 @@ typealias MortarElements2D Union{Seg2, Seg3}
 
 function assemble!{E<:MortarElements2D}(assembly::BoundaryAssembly, problem::BoundaryProblem{MortarProblem}, slave_element::Element{E}, time::Real)
 
+    # slave element must have a set of master elements
+    haskey(slave_element, "master elements") || return
+
     # get dimension and name of PARENT field
     field_dim = problem.parent_field_dim
     field_name = problem.parent_field_name