From 3f55152ca093edd90eba6cd2c979db0f32468900 Mon Sep 17 00:00:00 2001
From: Pierre-Emmanuel Viel <p.emmanuel.viel@gmail.com>
Date: Wed, 12 Aug 2020 23:07:35 +0200
Subject: [PATCH] Add debug assert to check in FLANN the vectors size is
 multiple of the architecture word size

---
 modules/flann/include/opencv2/flann/dist.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/modules/flann/include/opencv2/flann/dist.h b/modules/flann/include/opencv2/flann/dist.h
index e41b994d7e..b5a1f22532 100644
--- a/modules/flann/include/opencv2/flann/dist.h
+++ b/modules/flann/include/opencv2/flann/dist.h
@@ -683,6 +683,8 @@ struct Hamming2
     template <typename Iterator1, typename Iterator2>
     ResultType operator()(const Iterator1 a, const Iterator2 b, size_t size, ResultType /*worst_dist*/ = -1) const
     {
+        CV_DbgAssert(!(size % long_word_size_) && "vectors size must be multiple of long words size (i.e. 8)");
+
 #ifdef FLANN_PLATFORM_64_BIT
         const uint64_t* pa = reinterpret_cast<const uint64_t*>(a);
         const uint64_t* pb = reinterpret_cast<const uint64_t*>(b);
@@ -711,6 +713,8 @@ struct Hamming2
     template <typename Iterator1>
     ResultType operator()(const Iterator1 a, ZeroIterator<unsigned char> b, size_t size, ResultType /*worst_dist*/ = -1) const
     {
+        CV_DbgAssert(!(size % long_word_size_) && "vectors size must be multiple of long words size (i.e. 8)");
+
         (void)b;
 #ifdef FLANN_PLATFORM_64_BIT
         const uint64_t* pa = reinterpret_cast<const uint64_t*>(a);