pythongh-90872: Fix subprocess.Popen._wait() for negative timeout

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

Author: vstinner

Lib/subprocess.py

@@ -1586,6 +1586,8 @@ def _wait(self, timeout):
             """Internal implementation of wait() on Windows."""
             if timeout is None:
                 timeout_millis = _winapi.INFINITE
+            elif timeout <= 0:
+                timeout_millis = 0
             else:
                 timeout_millis = int(timeout * 1000)
             if self.returncode is None:

Misc/NEWS.d/next/Library/2024-03-19-11-08-26.gh-issue-90872.ghys95.rst

@@ -0,0 +1,3 @@
+On Windows, :meth:`subprocess.Popen.wait` no longer calls
+``WaitForSingleObject()`` with a negative timeout: pass ``0`` ms if the
+timeout is negative. Patch by Victor Stinner.