Improved self-cleaning tests.

tests/README.md

@@ -1,5 +1,46 @@
 # Wine control integration
 
+## Temporary files and failure inspection
+
+Wine CTests and the integration scripts below use fresh prefixes under the
+temporary directory (`/tmp` by default). Successful runs stop their Wine
+servers and remove their temporary files. **Failures, timeouts and ordinary
+interruptions retain the original files by default**, with the directory path
+printed before the test starts and again at exit. This preserves a one-off
+failure for inspection without requiring a second reproduction. Retention
+keeps files and registry state; test processes are still stopped.
+
+Console output and fixture `.log` files are saved under
+`<build-dir>/Testing/WineAccessLogs/`, outside the disposable prefix. These logs
+remain even when temporary files are removed. CTest also keeps its usual
+`Testing/Temporary/LastTest.log` report. Saved logs need occasional maintenance;
+review them for private text before sharing.
+
+To retain successful runs too, or explicitly clean a failed run:
+
+```sh
+xvfb-run -a python3 tests/menu_integration.py --build-dir build --keep
+xvfb-run -a python3 tests/menu_integration.py --build-dir build --clean-on-failure
+WINE_ACCESS_TEST_KEEP=1 xvfb-run -a ctest --test-dir build -V
+WINE_ACCESS_TEST_KEEP_ON_FAILURE=0 xvfb-run -a ctest --test-dir build --output-on-failure
+```
+
+Each run requires at least 1024 MiB free on the temporary filesystem before
+starting. If retained failures accumulate, the next run stops with an explicit
+space error; it never deletes earlier evidence automatically. Remove retained
+directories manually after inspecting them. `TMPDIR` can select another
+filesystem, and `WINE_ACCESS_TEST_MIN_FREE_MIB` can adjust the space guard for
+larger fixtures. CTests run serially because their fixtures share one display.
+A teardown or log-preservation failure always retains the temporary files.
+SIGKILL, machine shutdown and an outer test-runner kill cannot run Python
+cleanup; occasional `/tmp` cleanup remains useful.
+
+Check the runner without Wine:
+
+```sh
+python3 tests/wine_test_environment_test.py
+```
+
 ## UIA notifications
 
 UIA notification routing uses the actual native application hooks and a private