NumpyAllocator: check reference count before actual release, revert flann changes

modules/features2d/src/matchers.cpp

@@ -1022,27 +1022,12 @@ FlannBasedMatcher::FlannBasedMatcher( const Ptr<flann::IndexParams>& _indexParam
 void FlannBasedMatcher::add( InputArrayOfArrays _descriptors )
 {
     DescriptorMatcher::add( _descriptors );
-    if(_descriptors.isUMatVector() || _descriptors.isUMat())
+    std::vector<UMat> descriptors;
+    _descriptors.getUMatVector(descriptors);
+
+    for( size_t i = 0; i < descriptors.size(); i++ )
     {
-        std::vector<UMat> descriptors;
+        addedDescCount += descriptors[i].rows;
-        _descriptors.getUMatVector(descriptors);
-        for( size_t i = 0; i < descriptors.size(); i++ )
-        {
-            addedDescCount += descriptors[i].rows;
-        }
-    }
-    else if(_descriptors.isMatVector() || _descriptors.isMat())
-    {
-        std::vector<Mat> descriptors;
-        _descriptors.getMatVector(descriptors);
-        for( size_t i = 0; i < descriptors.size(); i++ )
-        {
-            addedDescCount += descriptors[i].rows;
-        }
-    }
-    else
-    {
-        CV_Assert( _descriptors.isUMat() || _descriptors.isUMatVector() || _descriptors.isMat() || _descriptors.isMatVector());
     }
 }
 

modules/python/src2/cv2.cpp

@@ -190,9 +190,13 @@ public:
 
     void deallocate(UMatData* u) const
     {
-        if(u)
+        if(!u)
+            return;
+        PyEnsureGIL gil;
+        CV_Assert(u->urefcount >= 0);
+        CV_Assert(u->refcount >= 0);
+        if(u->refcount == 0)
         {
-            PyEnsureGIL gil;
             PyObject* o = (PyObject*)u->userdata;
             Py_XDECREF(o);
             delete u;