Don't set QT_PLUGIN_PATH in the deployment test's run environment

Otherwise we don't properly test whether the deployed executable can run
without adjusting the environment.

We temporarily adjust the test_widgets_app_deployment test and set
CMAKE_INSTALL_LIBDIR to make the test pass.  It would now fail on Linux
distros where CMAKE_INSTALL_LIBDIR defaults to "lib64" but Qt is built
with lib dir "lib".  The next commit removes this hack.

Change-Id: I63c79ef1ee23ffaeed881337fde6e9d889ecc0fe
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

src/corelib/Qt6CTestMacros.cmake

@@ -163,6 +163,13 @@ function(_qt_internal_get_cmake_test_configure_options out_var)
 endfunction()
 
 function(_qt_internal_set_up_test_run_environment testname)
+    set(no_value_options NO_PLUGIN_PATH)
+    set(single_value_options "")
+    set(multi_value_options "")
+    cmake_parse_arguments(PARSE_ARGV 1 arg
+        "${no_value_options}" "${single_value_options}" "${multi_value_options}"
+    )
+
     # This is copy-pasted from qt_add_test and adapted to the standalone project case.
     if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
         set(QT_PATH_SEPARATOR "\\;")
@@ -201,20 +208,20 @@ function(_qt_internal_set_up_test_run_environment testname)
     set_property(TEST "${testname}" APPEND PROPERTY ENVIRONMENT "${test_env_path}")
     set_property(TEST "${testname}" APPEND PROPERTY ENVIRONMENT "QT_TEST_RUNNING_IN_CTEST=1")
 
-    # Add the install prefix to list of plugin paths when doing a prefix build
-    if(NOT QT_INSTALL_DIR)
-        foreach(install_prefix ${install_prefixes})
-            list(APPEND plugin_paths "${install_prefix}/${INSTALL_PLUGINSDIR}")
-        endforeach()
+    if(NOT arg_NO_PLUGIN_PATH)
+        # Add the install prefix to list of plugin paths when doing a prefix build
+        if(NOT QT_INSTALL_DIR)
+            foreach(install_prefix ${install_prefixes})
+                list(APPEND plugin_paths "${install_prefix}/${INSTALL_PLUGINSDIR}")
+            endforeach()
+        endif()
+
+        # TODO: Collect all paths from known repositories when performing a super build.
+        list(APPEND plugin_paths "${PROJECT_BINARY_DIR}/${INSTALL_PLUGINSDIR}")
+        list(JOIN plugin_paths "${QT_PATH_SEPARATOR}" plugin_paths_joined)
+        set_property(TEST "${testname}"
+            APPEND PROPERTY ENVIRONMENT "QT_PLUGIN_PATH=${plugin_paths_joined}")
     endif()
-
-    #TODO: Collect all paths from known repositories when performing a super
-    # build.
-    list(APPEND plugin_paths "${PROJECT_BINARY_DIR}/${INSTALL_PLUGINSDIR}")
-    list(JOIN plugin_paths "${QT_PATH_SEPARATOR}" plugin_paths_joined)
-    set_property(TEST "${testname}"
-                 APPEND PROPERTY ENVIRONMENT "QT_PLUGIN_PATH=${plugin_paths_joined}")
-
 endfunction()
 
 # Checks if the test project can be built successfully. Arguments:
@@ -259,6 +266,7 @@ macro(_qt_internal_test_expect_pass _dir)
       NO_CLEAN_STEP
       NO_BUILD_PROJECT_ARG
       NO_IOS_DEFAULT_ARGS
+      NO_RUN_ENVIRONMENT_PLUGIN_PATH
     )
     set(_test_single_args
       BINARY
@@ -435,7 +443,11 @@ macro(_qt_internal_test_expect_pass _dir)
     endif()
 
     if(_ARGS_BINARY)
-        _qt_internal_set_up_test_run_environment("${testname}")
+        set(run_env_args "")
+        if(_ARGS_NO_RUN_ENVIRONMENT_PLUGIN_PATH)
+            list(APPEND run_env_args NO_PLUGIN_PATH)
+        endif()
+        _qt_internal_set_up_test_run_environment("${testname}" ${run_env_args})
     endif()
 
     unset(__expect_pass_source_dir)

tests/auto/cmake/CMakeLists.txt

@@ -332,6 +332,7 @@ set(deploy_args
     # Need to explicitly specify a writable install prefix.
     BUILD_OPTIONS
         -DCMAKE_INSTALL_PREFIX=${CMAKE_CURRENT_BINARY_DIR}/test_widgets_app_deployment_installed
+    NO_RUN_ENVIRONMENT_PLUGIN_PATH
 )
 
 # For now, the test should only pass on Windows and macOS shared and static builds and fail on

tests/auto/cmake/test_widgets_app_deployment/CMakeLists.txt

@@ -5,6 +5,8 @@ cmake_minimum_required(VERSION 3.16)
 project(deployment_api)
 enable_testing()
 
+set(CMAKE_INSTALL_LIBDIR lib)  ### temporary hack to make the test pass - remove in next commit!
+
 find_package(Qt6 COMPONENTS REQUIRED Widgets Test)
 
 qt6_standard_project_setup()