From 555f0901a3906b363e767b6209a8da91191953d1 Mon Sep 17 00:00:00 2001
From: Varun Jaiswal <96684656+varun-jaiswal17@users.noreply.github.com>
Date: Tue, 16 Jun 2026 21:24:18 +0530
Subject: [PATCH] Merge pull request #29309 from
 varun-jaiswal17:fix_dll_mismatch

Fix ONNXRuntime dll path mismatch #29309

**1. C2664 build error in `net_impl_backend.cpp`**
`EnableProfiling()` expects `const wchar_t*` on Windows (`ORTCHAR_T`), but was passed `const char*`.

Fixed by converting to `std::wstring`, as suggested in #29278

---

**2. Wrong ORT DLL loaded at runtime (`modules/dnn/CMakeLists.txt`)**
With `DOWNLOAD_ONNXRUNTIME=ON`, the DLL glob only searched `bin/` but the downloaded package places DLLs in `lib/`. This left the build tree with no ORT DLL, causing Windows to fall back to the stale `System32\onnxruntime.dll` (1.17.1), crashing against the ORT 1.25.1 API.

Fixed by adding `lib/` as fallback and staging DLLs into the build bin directory at configure time.

Closes : #29278

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [x] The feature is well documented and sample code can be built with the project CMake
---
 modules/dnn/CMakeLists.txt           | 14 ++++++++++++++
 modules/dnn/src/net_impl_backend.cpp |  5 +++++
 2 files changed, 19 insertions(+)

diff --git a/modules/dnn/CMakeLists.txt b/modules/dnn/CMakeLists.txt
index a76548363c..358920fb3d 100644
--- a/modules/dnn/CMakeLists.txt
+++ b/modules/dnn/CMakeLists.txt
@@ -340,9 +340,23 @@ if(WITH_ONNXRUNTIME)
     if(WIN32)
       if(ONNXRT_ROOT_DIR)
         file(GLOB _ort_runtime_libs "${ONNXRT_ROOT_DIR}/bin/onnxruntime*.dll")
+        if(NOT _ort_runtime_libs)
+          file(GLOB _ort_runtime_libs "${ONNXRT_ROOT_DIR}/lib/onnxruntime*.dll")
+        endif()
       endif()
       if(_ort_runtime_libs)
         install(FILES ${_ort_runtime_libs} DESTINATION ${OPENCV_BIN_INSTALL_PATH} COMPONENT libs)
+        foreach(_ort_dll ${_ort_runtime_libs})
+          if(MSVC_IDE)
+            execute_process(
+              COMMAND ${CMAKE_COMMAND} -E copy_if_different "${_ort_dll}" "${EXECUTABLE_OUTPUT_PATH}/Release/"
+              COMMAND ${CMAKE_COMMAND} -E copy_if_different "${_ort_dll}" "${EXECUTABLE_OUTPUT_PATH}/Debug/")
+          elseif(MSVC AND (CMAKE_GENERATOR MATCHES "Visual"))
+            execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different "${_ort_dll}" "${EXECUTABLE_OUTPUT_PATH}/${CMAKE_BUILD_TYPE}/")
+          else()
+            execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different "${_ort_dll}" "${EXECUTABLE_OUTPUT_PATH}/")
+          endif()
+        endforeach()
       endif()
     elseif(APPLE)
       if(ONNXRT_ROOT_DIR)
diff --git a/modules/dnn/src/net_impl_backend.cpp b/modules/dnn/src/net_impl_backend.cpp
index 0e4bdf1f41..47536c0ebf 100644
--- a/modules/dnn/src/net_impl_backend.cpp
+++ b/modules/dnn/src/net_impl_backend.cpp
@@ -96,7 +96,12 @@ void Net::Impl::finalizeOrt()
     ort_profile_data.clear();
     if (profilingMode != DNN_PROFILE_NONE) {
         ort_profile_path_prefix = cv::tempfile("opencv_ort_profile_");
+#ifdef _WIN32
+        std::wstring w_profile_path(ort_profile_path_prefix.begin(), ort_profile_path_prefix.end());
+        opts.EnableProfiling(w_profile_path.c_str());
+#else
         opts.EnableProfiling(ort_profile_path_prefix.c_str());
+#endif
     }
 
 #ifdef _WIN32