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

diff --cc doc/opencv.bib
Simple merge

diff --cc modules/core/include/opencv2/core/check.hpp
Simple merge

diff --cc modules/core/src/check.cpp
index 7f1310a,1c0471a..ffd9b30
--- 1/modules/core/src/check.cpp
--- 2/modules/core/src/check.cpp
+++ b/modules/core/src/check.cpp
@@@ -151,6 -155,22 +155,22 @@@ void check_failed_MatChannels(const in
  {
      check_failed_auto_<int>(v, ctx);
  }
 -    cv::errorNoReturn(cv::Error::StsError, ss.str(), ctx.func, ctx.file, ctx.line);
+ void check_failed_true(const bool v, const CheckContext& ctx)
+ {
+     CV_UNUSED(v);
+     std::stringstream ss;
+     ss  << ctx.message << ":" << std::endl
+         << "    '" << ctx.p1_str << "' must be 'true'";
 -    cv::errorNoReturn(cv::Error::StsError, ss.str(), ctx.func, ctx.file, ctx.line);
++    cv::error(cv::Error::StsError, ss.str(), ctx.func, ctx.file, ctx.line);
+ }
+ void check_failed_false(const bool v, const CheckContext& ctx)
+ {
+     CV_UNUSED(v);
+     std::stringstream ss;
+     ss  << ctx.message << ":" << std::endl
+         << "    '" << ctx.p1_str << "' must be 'false'";
++    cv::error(cv::Error::StsError, ss.str(), ctx.func, ctx.file, ctx.line);
+ }
  void check_failed_auto(const int v, const CheckContext& ctx)
  {
      check_failed_auto_<int>(v, ctx);

diff --cc modules/imgcodecs/src/grfmt_webp.cpp
Simple merge

diff --cc modules/imgproc/src/smooth.dispatch.cpp
Simple merge

diff --cc modules/ts/misc/run_long.py
Simple merge