Fixes issue #14396: Handle the odd rare case of waitpid returning 0
when not expected in subprocess.Popen.wait().
diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index 57cc1a4..296613a 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -1509,9 +1509,13 @@
raise TimeoutExpired(self.args, timeout)
delay = min(delay * 2, remaining, .05)
time.sleep(delay)
- elif self.returncode is None:
- (pid, sts) = self._try_wait(0)
- self._handle_exitstatus(sts)
+ else:
+ while self.returncode is None:
+ (pid, sts) = self._try_wait(0)
+ # Check the pid and loop as waitpid has been known to return
+ # 0 even without WNOHANG in odd situations. issue14396.
+ if pid == self.pid:
+ self._handle_exitstatus(sts)
return self.returncode
diff --git a/Misc/NEWS b/Misc/NEWS
index 44e0da2..dea9c8a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -83,6 +83,9 @@
Library
-------
+- Issue #14396: Handle the odd rare case of waitpid returning 0 when not
+ expected in subprocess.Popen.wait().
+
- Issue #16411: Fix a bug where zlib.decompressobj().flush() might try to access
previously-freed memory. Patch by Serhiy Storchaka.