From 89e3e448f58ebff525888ed97f6b7f7768ab567f Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.alekhin@itseez.com>
Date: Wed, 12 Mar 2014 15:54:55 +0400
Subject: [PATCH] features2d: workaround for 'utrainDescCollection' issue (PR
 #2142)

---
 modules/features2d/src/matchers.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/modules/features2d/src/matchers.cpp b/modules/features2d/src/matchers.cpp
index 6bc925f..91ee9d9 100644
--- a/modules/features2d/src/matchers.cpp
+++ b/modules/features2d/src/matchers.cpp
@@ -1232,6 +1232,13 @@ void FlannBasedMatcher::train()
 {
     if( !flannIndex || mergedDescriptors.size() < addedDescCount )
     {
+        // FIXIT: Workaround for 'utrainDescCollection' issue (PR #2142)
+        if (!utrainDescCollection.empty())
+        {
+            CV_Assert(trainDescCollection.size() == 0);
+            for (size_t i = 0; i < utrainDescCollection.size(); ++i)
+                trainDescCollection.push_back(utrainDescCollection[i].getMat(ACCESS_READ));
+        }
         mergedDescriptors.set( trainDescCollection );
         flannIndex = makePtr<flann::Index>( mergedDescriptors.getDescriptors(), *indexParams );
     }
-- 
2.7.4