Hotfix: Refine Surface on Outer Edge

src/refine_surface.f90

@@ -225,17 +225,27 @@ do iedge=1,nedge
        if (dist0>distmax) then
            !maxdist in right hand triangle
            tr1 = ed(iedge)%t1
-           maxdist1 = maxval( edlen(surface%icon(:,tr1)) )-eps
+           !If edge is part of the complex hull, one triangle is 0
+           !If not caught by if-clauses, this will cause segfault
+           if (tr1>0) then
+               maxdist1 = maxval( edlen(surface%icon(:,tr1)) )-eps
+           else
+               maxdist1 = 0.d0
+           end if
            !maxdist in left hand triangle
            tr2 = ed(iedge)%t2
-           maxdist2 = maxval( edlen(surface%icon(:,tr2)) )-eps
+           if (tr2>0) then
+               maxdist2 = maxval( edlen(surface%icon(:,tr2)) )-eps
+           else
+               maxdist2 = 0.d0
+           end if
            !Is this edge one of the longest?
            if (dist0>=maxdist1 .OR. dist0>=maxdist2) then
                refine(iedge) = .true.
                !block all edges in both triangles
                do k = 1,3
-                   blocked(surface%icon(k,tr1))=.true.
-                   blocked(surface%icon(k,tr2))=.true.
+                   if (tr1>0) blocked(surface%icon(k,tr1))=.true.
+                   if (tr2>0) blocked(surface%icon(k,tr2))=.true.
                end do
            end if
        end if