From 9dee2c6e6735230fcea83c3db7f5656df834ae4f Mon Sep 17 00:00:00 2001
From: Alexander Smorkalov <alexander.smorkalov@xperience.ai>
Date: Tue, 6 Aug 2024 10:40:45 +0300
Subject: [PATCH] Fixed asserts in fillPoly.

---
 .../imgproc/misc/python/test/test_imgproc.py  | 21 +++++++++++++++++++
 modules/imgproc/src/drawing.cpp               |  9 +++++---
 2 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 modules/imgproc/misc/python/test/test_imgproc.py

diff --git a/modules/imgproc/misc/python/test/test_imgproc.py b/modules/imgproc/misc/python/test/test_imgproc.py
new file mode 100644
index 0000000000..9979b0c301
--- /dev/null
+++ b/modules/imgproc/misc/python/test/test_imgproc.py
@@ -0,0 +1,21 @@
+#!/usr/bin/env python
+
+from __future__ import print_function
+
+import numpy as np
+import cv2 as cv
+
+from tests_common import NewOpenCVTests
+
+class Imgproc_Tests(NewOpenCVTests):
+
+    def test_python_986(self):
+        cntls = []
+        img = np.zeros((100,100,3), dtype=np.uint8)
+        color = (0,0,0)
+        cnts = np.array(cntls, dtype=np.int32).reshape((1, -1, 2))
+        try:
+            cv.fillPoly(img, cnts, color)
+            assert False
+        except:
+            assert True
diff --git a/modules/imgproc/src/drawing.cpp b/modules/imgproc/src/drawing.cpp
index 4d0f26f7a0..394a6d6059 100644
--- a/modules/imgproc/src/drawing.cpp
+++ b/modules/imgproc/src/drawing.cpp
@@ -2044,8 +2044,11 @@ void fillPoly( InputOutputArray _img, const Point** pts, const int* npts, int nc
     edges.reserve( total + 1 );
     for (i = 0; i < ncontours; i++)
     {
-        std::vector<Point2l> _pts(pts[i], pts[i] + npts[i]);
-        CollectPolyEdges(img, _pts.data(), npts[i], edges, buf, line_type, shift, offset);
+        if (npts[i] > 0 && pts[i])
+        {
+            std::vector<Point2l> _pts(pts[i], pts[i] + npts[i]);
+            CollectPolyEdges(img, _pts.data(), npts[i], edges, buf, line_type, shift, offset);
+        }
     }
 
     FillEdgeCollection(img, edges, buf, line_type);
@@ -2430,7 +2433,7 @@ void cv::fillPoly(InputOutputArray img, InputArrayOfArrays pts,
     for( i = 0; i < ncontours; i++ )
     {
         Mat p = pts.getMat(manyContours ? i : -1);
-        CV_Assert(p.checkVector(2, CV_32S) >= 0);
+        CV_Assert(p.checkVector(2, CV_32S) > 0);
         ptsptr[i] = p.ptr<Point>();
         npts[i] = p.rows*p.cols*p.channels()/2;
     }