From c6b63e0e28001e0def94850feaa8c8851769ce92 Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.a.alekhin@gmail.com>
Date: Thu, 1 Oct 2020 15:20:32 +0000
Subject: [PATCH] calib3d/imgproc: add GCGraph::maxFlow() missing empty checks

---
 modules/imgproc/src/gcgraph.hpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/modules/imgproc/src/gcgraph.hpp b/modules/imgproc/src/gcgraph.hpp
index 16c25de..8730e1f 100644
--- a/modules/imgproc/src/gcgraph.hpp
+++ b/modules/imgproc/src/gcgraph.hpp
@@ -152,6 +152,8 @@ void GCGraph<TWeight>::addTermWeights( int i, TWeight sourceW, TWeight sinkW )
 template <class TWeight>
 TWeight GCGraph<TWeight>::maxFlow()
 {
+    CV_Assert(!vtcs.empty());
+    CV_Assert(!edges.empty());
     const int TERMINAL = -1, ORPHAN = -2;
     Vtx stub, *nilNode = &stub, *first = nilNode, *last = nilNode;
     int curr_ts = 0;
-- 
2.7.4