From 0d7a37c1e79cc15d95634d10e53cddfa6019dede Mon Sep 17 00:00:00 2001
From: Maria Dimashova <no@email>
Date: Thu, 21 Jul 2011 09:38:25 +0000
Subject: [PATCH] added an ability to make push_back to the empty matrix

---
 modules/core/include/opencv2/core/mat.hpp | 7 ++++++-
 modules/core/src/matrix.cpp               | 5 +++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/modules/core/include/opencv2/core/mat.hpp b/modules/core/include/opencv2/core/mat.hpp
index a69673820..a7b2041eb 100644
--- a/modules/core/include/opencv2/core/mat.hpp
+++ b/modules/core/include/opencv2/core/mat.hpp
@@ -675,7 +675,12 @@ template<typename _Tp, int m, int n> inline Mat::operator Matx<_Tp, m, n>() cons
 
 template<typename _Tp> inline void Mat::push_back(const _Tp& elem)
 {
-    CV_Assert(DataType<_Tp>::type == type() && cols == 1
+    if( !data )
+	{
+		*this = Mat(1, 1, DataType<_Tp>::type, (void*)&elem).clone();
+		return;
+	}
+	CV_Assert(DataType<_Tp>::type == type() && cols == 1
               /* && dims == 2 (cols == 1 implies dims == 2) */);
     uchar* tmp = dataend + step[0];
     if( !isSubmatrix() && isContinuous() && tmp <= datalimit )
diff --git a/modules/core/src/matrix.cpp b/modules/core/src/matrix.cpp
index 4654a78f4..e55b0031a 100644
--- a/modules/core/src/matrix.cpp
+++ b/modules/core/src/matrix.cpp
@@ -585,6 +585,11 @@ void Mat::push_back(const Mat& elems)
         push_back(tmp);
         return;
     }
+	if( !data )
+	{
+		*this = elems.clone();
+		return;
+	}
 
     size.p[0] = elems.size.p[0];
     bool eq = size == elems.size;