test_warnings ironically had a single test that was not protecting the warnings

filter and was resetting it.

Lib/test/test_warnings.py

@@ -460,14 +460,14 @@ class _WarningsTests(BaseTest):
         self.failUnless(text in result)
 
     def test_showwarning_not_callable(self):
-        self.module.filterwarnings("always", category=UserWarning)
+        with original_warnings.catch_warnings(module=self.module):
-        old_showwarning = self.module.showwarning
+            self.module.filterwarnings("always", category=UserWarning)
-        self.module.showwarning = 23
+            old_showwarning = self.module.showwarning
-        try:
+            self.module.showwarning = 23
-            self.assertRaises(TypeError, self.module.warn, "Warning!")
+            try:
-        finally:
+                self.assertRaises(TypeError, self.module.warn, "Warning!")
-            self.module.showwarning = old_showwarning
+            finally:
-            self.module.resetwarnings()
+                self.module.showwarning = old_showwarning
 
     def test_show_warning_output(self):
         # With showarning() missing, make sure that output is okay.

Misc/NEWS

@@ -730,6 +730,8 @@ Extension Modules
 Tests
 -----
 
+- Fix test_warnings to no longer reset the warnings filter.
+
 - Fix test_logging to no longer reset the warnings filter.
 
 - Issue #5635: Fix running test_sys with tracing enabled.