Merge remote-tracking branch 'upstream/3.4' into merge-3.4

modules/imgproc/test/test_lsd.cpp

@@ -5,8 +5,6 @@
 
 namespace opencv_test { namespace {
 
-#if 0  // LSD implementation has been removed due original code license issues
-
 const Size img_size(640, 480);
 const int LSD_TEST_SEED = 0x134679;
 const int EPOCHS = 20;
@@ -404,6 +402,4 @@ TEST_F(Imgproc_LSD_Common, compareSegmentsVec4i)
     ASSERT_EQ(result2, 11);
 }
 
-#endif
-
 }} // namespace

modules/imgproc/test/test_smooth_bitexact.cpp

@@ -249,4 +249,15 @@ TEST(GaussianBlur_Bitexact, regression_9863)
     checkGaussianBlur_8Uvs32F(src8u, src32f, 151, 30);
 }
 
+TEST(GaussianBlur_Bitexact, overflow_20792)
+{
+    Mat src(128, 128, CV_16UC1, Scalar(255));
+    Mat dst;
+    double sigma = theRNG().uniform(0.0, 0.2);        // a peaky kernel
+    GaussianBlur(src, dst, Size(7, 7), sigma, 0.9);
+    int count = (int)countNonZero(dst);
+    int nintyPercent = (int)(src.rows*src.cols * 0.9);
+    EXPECT_GT(count, nintyPercent);
+}
+
 }} // namespace