hopefully, fixed crash in sparse mat test

modules/core/src/matrix.cpp

@@ -4816,7 +4816,8 @@ void SparseMat::copyTo( SparseMat& m ) const
 void SparseMat::copyTo( Mat& m ) const
 {
     CV_Assert( hdr );
-    m.create( dims(), hdr->size, type() );
+    int ndims = dims();
+    m.create( ndims, hdr->size, type() );
     m = Scalar(0);
 
     SparseMatConstIterator from = begin();
@@ -4825,7 +4826,7 @@ void SparseMat::copyTo( Mat& m ) const
     for( i = 0; i < N; i++, ++from )
     {
         const Node* n = from.node();
-        copyElem( from.ptr, m.ptr(n->idx), esz);
+        copyElem( from.ptr, (ndims > 1 ? m.ptr(n->idx) : m.ptr(n->idx[0])), esz);
     }
 }