New submission from Dariusz Walczak <dariusz.walc...@gmail.com>: It's possible to lose data piped through standard output and/or error streams when large ammounts of data are transfered.
Reproduction: 1) Process A spawns process B with all standard I/O pipes and transfers large ammount of data to it (100kB in my sample). 2) Process B exits very early (doesn't process all stdin data) and puts large amount of data into its stderr or stdout streams. 3) IOError/OSError exception if errno variable set to errno.EPIPE is raised on process A side. Bug: When the exception is catched Popen object's stdout and stderr members may not contain data put into stderr/stdout streams by process B. Note: Described behaviour can be observed in Python 2.6.1 on FreeBSD 7.2 as well as on Windows XP (Pro x64, SP2, up to date). Real life example of such early end of process B: openssl smime -verify -CApath /some/dir with large, unsigned email. I attach simple reproduction code (execute sender.py script). ---------- components: Library (Lib) files: subprocess.Popen.communicate_problem_reproduction.zip messages: 90391 nosy: dwalczak severity: normal status: open title: subprocess.Popen.communicate can lose data from output/error streams when broken input pipe occures type: behavior versions: Python 2.6 Added file: http://bugs.python.org/file14482/subprocess.Popen.communicate_problem_reproduction.zip _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue6457> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
