cmake: DOWNLOAD_EXTERNAL_TEST_DATA option

modules/dnn/CMakeLists.txt

@@ -27,8 +27,9 @@ ocv_add_perf_tests()
 # ----------------------------------------------------------------------------
 # Download pre-trained models for complex testing on GoogLeNet and AlexNet
 # ----------------------------------------------------------------------------
-OCV_OPTION(${the_module}_DOWNLOAD_CAFFE_MODELS "Use GoogLeNet Caffe model for testing" ON IF BUILD_TESTS AND PYTHON2_EXECUTABLE AND DEFINED ENV{OPENCV_TEST_DATA_PATH})
-if(BUILD_TESTS AND ${the_module}_DOWNLOAD_CAFFE_MODELS)
+OCV_OPTION(${the_module}_DOWNLOAD_CAFFE_MODELS "Use GoogLeNet Caffe model for testing" OFF IF BUILD_TESTS AND PYTHON2_EXECUTABLE AND DEFINED ENV{OPENCV_TEST_DATA_PATH})
+if(BUILD_TESTS AND PYTHON2_EXECUTABLE AND DEFINED ENV{OPENCV_TEST_DATA_PATH}
+        AND (DOWNLOAD_EXTERNAL_TEST_DATA OR ${the_module}_DOWNLOAD_CAFFE_MODELS))
     add_custom_command( TARGET opencv_test_${name} POST_BUILD
                         COMMAND ${PYTHON2_EXECUTABLE} download_model.py test_models.json
                         WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/scripts )