From ce72ee781577a78e11ff76f1fcd8403e5ee23542 Mon Sep 17 00:00:00 2001
From: schillic <git@christianschilling.net>
Date: Fri, 26 Jul 2024 16:23:14 +0200
Subject: [PATCH] test for return status of 'remove_redundant_constraints'

---
 src/Sets/HPolyhedron/ishyperplanar.jl | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Sets/HPolyhedron/ishyperplanar.jl b/src/Sets/HPolyhedron/ishyperplanar.jl
index 4a0d4ffe0c..4669a82341 100644
--- a/src/Sets/HPolyhedron/ishyperplanar.jl
+++ b/src/Sets/HPolyhedron/ishyperplanar.jl
@@ -6,6 +6,10 @@ function ishyperplanar(P::HPolyhedron)
     if m > 2
         # try to remove redundant constraints
         clist = remove_redundant_constraints(clist)
+        if isnothing(clist)
+            # constraints are contradictory
+            return false
+        end
         m = length(clist)
     end
     if m != 2