From 6997d423c8149ac334aa97a8c2348fd533953395 Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.alekhin@itseez.com>
Date: Fri, 25 Dec 2015 15:33:06 +0300
Subject: [PATCH 1/2] fix normalize in case of inplace operations

fixes #5876
---
 modules/core/src/convert.cpp | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/modules/core/src/convert.cpp b/modules/core/src/convert.cpp
index 6c693a43a0..f41bfa105f 100644
--- a/modules/core/src/convert.cpp
+++ b/modules/core/src/convert.cpp
@@ -5352,22 +5352,21 @@ void cv::normalize( InputArray _src, InputOutputArray _dst, double a, double b,
     else
         CV_Error( CV_StsBadArg, "Unknown/unsupported norm type" );
 
-    int type = _src.type(), depth = CV_MAT_DEPTH(type), cn = CV_MAT_CN(type);
+    int type = _src.type(), depth = CV_MAT_DEPTH(type);
     if( rtype < 0 )
         rtype = _dst.fixedType() ? _dst.depth() : depth;
-    _dst.createSameSize(_src, CV_MAKETYPE(rtype, cn));
 
     CV_OCL_RUN(_dst.isUMat(),
                ocl_normalize(_src, _dst, _mask, rtype, scale, shift))
 
-    Mat src = _src.getMat(), dst = _dst.getMat();
+    Mat src = _src.getMat();
     if( _mask.empty() )
-        src.convertTo( dst, rtype, scale, shift );
+        src.convertTo( _dst, rtype, scale, shift );
     else
     {
         Mat temp;
         src.convertTo( temp, rtype, scale, shift );
-        temp.copyTo( dst, _mask );
+        temp.copyTo( _dst, _mask );
     }
 }
 

From 17e4d33b0e0f2927e75fd16603ab1e8825b1fc56 Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.alekhin@itseez.com>
Date: Fri, 25 Dec 2015 16:02:47 +0300
Subject: [PATCH 2/2] added regression test for #5876

---
 modules/core/test/ocl/test_arithm.cpp | 16 ++++++++++++++++
 modules/core/test/test_arithm.cpp     | 11 +++++++++++
 2 files changed, 27 insertions(+)

diff --git a/modules/core/test/ocl/test_arithm.cpp b/modules/core/test/ocl/test_arithm.cpp
index f1efe9b22d..85dca9649b 100644
--- a/modules/core/test/ocl/test_arithm.cpp
+++ b/modules/core/test/ocl/test_arithm.cpp
@@ -1885,6 +1885,22 @@ OCL_INSTANTIATE_TEST_CASE_P(Arithm, ReduceMin, Combine(testing::Values(std::make
                                                        OCL_ALL_CHANNELS, testing::Values(0, 1), Bool()));
 
 
+// T-API BUG (haveOpenCL() is false): modules/core/src/matrix.cpp:212: error: (-215) u->refcount == 0 in function deallocate
+OCL_TEST(Normalize, DISABLED_regression_5876_inplace_change_type)
+{
+    double initial_values[] = {1, 2, 5, 4, 3};
+    float result_values[] = {0, 0.25, 1, 0.75, 0.5};
+    Mat m(Size(5, 1), CV_64FC1, initial_values);
+    Mat result(Size(5, 1), CV_32FC1, result_values);
+
+    UMat um; m.copyTo(um);
+    UMat uresult; result.copyTo(uresult);
+
+    OCL_ON(normalize(um, um, 1, 0, NORM_MINMAX, CV_32F));
+
+    EXPECT_EQ(0, cvtest::norm(um, uresult, NORM_INF));
+}
+
 } } // namespace cvtest::ocl
 
 #endif // HAVE_OPENCL
diff --git a/modules/core/test/test_arithm.cpp b/modules/core/test/test_arithm.cpp
index 0471ffc0b4..ace7950a64 100644
--- a/modules/core/test/test_arithm.cpp
+++ b/modules/core/test/test_arithm.cpp
@@ -1833,3 +1833,14 @@ TEST(MinMaxLoc, Mat_IntMax_Without_Mask)
     ASSERT_EQ(Point(0, 0), minLoc);
     ASSERT_EQ(Point(0, 0), maxLoc);
 }
+
+TEST(Normalize, regression_5876_inplace_change_type)
+{
+    double initial_values[] = {1, 2, 5, 4, 3};
+    float result_values[] = {0, 0.25, 1, 0.75, 0.5};
+    Mat m(Size(5, 1), CV_64FC1, initial_values);
+    Mat result(Size(5, 1), CV_32FC1, result_values);
+
+    normalize(m, m, 1, 0, NORM_MINMAX, CV_32F);
+    EXPECT_EQ(0, cvtest::norm(m, result, NORM_INF));
+}