gh-90872: Fix subprocess.Popen.wait() for negative timeout (#116989)

On Windows, subprocess.Popen.wait() no longer calls
WaitForSingleObject() with a negative timeout: pass 0 ms if the
timeout is negative.

1 files changed, 16 insertions, 0 deletions

diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index c44a778..d20b987 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -1607,6 +1607,22 @@ class ProcessTestCase(BaseTestCase):
         self.assertIsInstance(subprocess.Popen[bytes], types.GenericAlias)
         self.assertIsInstance(subprocess.CompletedProcess[str], types.GenericAlias)
 
+    @unittest.skipUnless(hasattr(subprocess, '_winapi'),
+                         'need subprocess._winapi')
+    def test_wait_negative_timeout(self):
+        proc = subprocess.Popen(ZERO_RETURN_CMD)
+        with proc:
+            patch = mock.patch.object(
+                subprocess._winapi,
+                'WaitForSingleObject',
+                return_value=subprocess._winapi.WAIT_OBJECT_0)
+            with patch as mock_wait:
+                proc.wait(-1)  # negative timeout
+                mock_wait.assert_called_once_with(proc._handle, 0)
+                proc.returncode = None
+
+            self.assertEqual(proc.wait(), 0)
+
 
 class RunFuncTestCase(BaseTestCase):
     def run_python(self, code, **kwargs):