threading_cleanup() failure marks test as ENV_CHANGED (#2500)

If threading_cleanup() fails to cleanup threads, set a a new
support.environment_altered flag to true, flag uses by save_env which
is used by regrtest to check if a test altered the environment. At
the end, the test file fails with ENV_CHANGED instead of SUCCESS, to
report that it altered the environment.

2 files changed, 10 insertions, 1 deletions

diff --git a/Lib/test/libregrtest/runtest.py b/Lib/test/libregrtest/runtest.py
index fda4ca1..0210409 100644
--- a/Lib/test/libregrtest/runtest.py
+++ b/Lib/test/libregrtest/runtest.py
@@ -103,6 +103,9 @@ def runtest(ns, test):
         faulthandler.dump_traceback_later(ns.timeout, exit=True)
     try:
         support.match_tests = ns.match_tests
+        # reset the environment_altered flag to detect if a test altered
+        # the environment
+        support.environment_altered = False
         if ns.failfast:
             support.failfast = True
         if output_on_failure:
diff --git a/Lib/test/libregrtest/save_env.py b/Lib/test/libregrtest/save_env.py
index 8309f26..3c45621 100644
--- a/Lib/test/libregrtest/save_env.py
+++ b/Lib/test/libregrtest/save_env.py
@@ -268,7 +268,13 @@ class saved_test_environment:
     def __exit__(self, exc_type, exc_val, exc_tb):
         saved_values = self.saved_values
         del self.saved_values
-        support.gc_collect()  # Some resources use weak references
+
+        # Some resources use weak references
+        support.gc_collect()
+
+        # Read support.environment_altered, set by support helper functions
+        self.changed |= support.environment_altered
+
         for name, get, restore in self.resource_info():
             current = get()
             original = saved_values.pop(name)