From 6c1a433c4c6933ec1be1643df67197b00e225d97 Mon Sep 17 00:00:00 2001
From: Pavel Rojtberg <rojtberg@gmail.com>
Date: Tue, 2 Feb 2021 02:49:19 +0100
Subject: [PATCH] python: also catch general c++ exceptions

they might be thrown from third-party code (notably Ogre in the ovis
module).
While Linux is kind enough to print them, they cause instant termination
on Windows.
Arguably, they do not origin from OpenCV itself, but still this helps
understanding what went wrong when calling an OpenCV function.
---
 modules/core/include/opencv2/core/bindings_utils.hpp | 8 ++++++++
 modules/python/src2/cv2.cpp                          | 5 +++++
 modules/python/test/test_misc.py                     | 6 ++++++
 3 files changed, 19 insertions(+)

diff --git a/modules/core/include/opencv2/core/bindings_utils.hpp b/modules/core/include/opencv2/core/bindings_utils.hpp
index bbcc3a88d0..179d60323f 100644
--- a/modules/core/include/opencv2/core/bindings_utils.hpp
+++ b/modules/core/include/opencv2/core/bindings_utils.hpp
@@ -8,6 +8,8 @@
 #include <opencv2/core/async.hpp>
 #include <opencv2/core/detail/async_promise.hpp>
 
+#include <stdexcept>
+
 namespace cv { namespace utils {
 //! @addtogroup core_utils
 //! @{
@@ -113,6 +115,12 @@ String dumpRange(const Range& argument)
     }
 }
 
+CV_WRAP static inline
+void testRaiseGeneralException()
+{
+    throw std::runtime_error("exception text");
+}
+
 CV_WRAP static inline
 AsyncArray testAsyncArray(InputArray argument)
 {
diff --git a/modules/python/src2/cv2.cpp b/modules/python/src2/cv2.cpp
index 8272513e64..8bb15cd43f 100644
--- a/modules/python/src2/cv2.cpp
+++ b/modules/python/src2/cv2.cpp
@@ -206,6 +206,11 @@ catch (const cv::Exception &e) \
 { \
     pyRaiseCVException(e); \
     return 0; \
+} \
+catch (const std::exception &e) \
+{ \
+    PyErr_SetString(opencv_error, e.what()); \
+    return 0; \
 }
 
 using namespace cv;
diff --git a/modules/python/test/test_misc.py b/modules/python/test/test_misc.py
index 5e23045e05..121e86a64c 100644
--- a/modules/python/test/test_misc.py
+++ b/modules/python/test/test_misc.py
@@ -47,6 +47,12 @@ class Bindings(NewOpenCVTests):
         boost.getMaxDepth()  # from ml::DTrees
         boost.isClassifier()  # from ml::StatModel
 
+    def test_raiseGeneralException(self):
+        with self.assertRaises((cv.error,),
+                            msg='C++ exception is not propagated to Python in the right way') as cm:
+            cv.utils.testRaiseGeneralException()
+        self.assertEqual(str(cm.exception), 'exception text')
+
     def test_redirectError(self):
         try:
             cv.imshow("", None)  # This causes an assert