Message ID | 20170725150951.16038-3-ldoktor@redhat.com |
---|---|
State | New |
Headers | show |
On 07/25/2017 11:09 AM, Lukáš Doktor wrote: > The list object is mutable in python and potentially might modify other > object's arguments when used as default argument. Reproducer: > > >>> vm1 = QEMUMachine("qemu") > >>> vm2 = QEMUMachine("qemu") > >>> vm1._wrapper.append("foo") > >>> print vm2._wrapper > ['foo'] > > In this case the `args` is actually copied so it would be safe to keep > it, but it's not a good practice to keep it. The same issue applies in > inherited qtest module. > ohh, grr, this trips me up in Python all the time. Definitely best to remove such usages where possible. > Signed-off-by: Lukáš Doktor <ldoktor@redhat.com> > Reviewed-by: Eduardo Habkost <ehabkost@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com>
diff --git a/scripts/qemu.py b/scripts/qemu.py index 191c916..66fd863 100644 --- a/scripts/qemu.py +++ b/scripts/qemu.py @@ -23,7 +23,7 @@ import qmp.qmp class QEMUMachine(object): '''A QEMU VM''' - def __init__(self, binary, args=[], wrapper=[], name=None, + def __init__(self, binary, args=None, wrapper=None, name=None, test_dir="/var/tmp", monitor_address=None, socket_scm_helper=None, debug=False): ''' @@ -39,6 +39,10 @@ class QEMUMachine(object): @param debug: enable debug mode (forwarded to QMP helper and such) @note: Qemu process is not started until launch() is used. ''' + if args is None: + args = [] + if wrapper is None: + wrapper = [] if name is None: name = "qemu-%d" % os.getpid() if monitor_address is None: diff --git a/scripts/qtest.py b/scripts/qtest.py index d5aecb5..ab183c0 100644 --- a/scripts/qtest.py +++ b/scripts/qtest.py @@ -79,7 +79,7 @@ class QEMUQtestProtocol(object): class QEMUQtestMachine(qemu.QEMUMachine): '''A QEMU VM''' - def __init__(self, binary, args=[], name=None, test_dir="/var/tmp", + def __init__(self, binary, args=None, name=None, test_dir="/var/tmp", socket_scm_helper=None): if name is None: name = "qemu-%d" % os.getpid()