[Python-checkins] cpython (merge 3.2 -> 3.3): Fixes issue #14396: Handle the odd rare case of waitpid returning 0

[gregory.p.smith]

http://hg.python.org/cpython/rev/61a0eace0f2e
changeset:   80363:61a0eace0f2e
branch:      3.3
parent:      80359:c7d6cd3c27b9
parent:      80362:d478df13abde
user:        Gregory P. Smith <greg at krypto.org>
date:        Sat Nov 10 21:06:18 2012 -0800
summary:
  Fixes issue #14396: Handle the odd rare case of waitpid returning 0
when not expected in subprocess.Popen.wait().

files:
  Lib/subprocess.py |  10 +++++++---
  Misc/NEWS         |   3 +++
  2 files changed, 10 insertions(+), 3 deletions(-)


diff --git a/Lib/subprocess.py b/Lib/subprocess.py
--- 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
--- 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.
 

-- 
Repository URL: http://hg.python.org/cpython