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From: Markus Armbruster <armbru@redhat.com>
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Date: Wed, 17 Sep 2014 12:06:54 +0200
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	(Gonglei's message of "Wed, 17 Sep 2014 09:17:05 +0000")
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Subject: Re: [Qemu-devel] [PATCH] qdev-monitor: fix segmentation fault on
	qdev_device_help()
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To: "Gonglei (Arei)" <arei.gonglei@huawei.com>
Cc: "Huangweidong (C)" <weidong.huang@huawei.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, "Huangpeng (Peter)" <peter.huangpeng@huawei.com>, "lcapitulino@redhat.com" <lcapitulino@redhat.com>, "stefanha@redhat.com" <stefanha@redhat.com>, "imammedo@redhat.com" <imammedo@redhat.com>, "afaerber@suse.de" <afaerber@suse.de>

"Gonglei (Arei)" <arei.gonglei@huawei.com> writes:

>> > >>
>> > >> Doesn't this leak prop_list when local_err && prop_list?
>> > >>
>> > > No, it will not happen this situation.
>> > >
>> > >> Returning both a value in need of destruction and an error object is at
>> > >> least highly unusual, and probably plain wrong.
>> > >>
>> > >> Should qmp_device_list_properties() return NULL when it sets an error?
>> > >
>> > > Yes, it was.
>> >
>> > I think I'm starting to understand now.
>> >
>> > You backtrace shows qmp_device_list_properties() returned null without
>> > setting an error.  But this is okay, because null means "empty list",
>> > which is a valid return value.
>> >
>> Yes.
>> 
>> > A systematic search for this kind of incorrect error handling would be
>> > nice: search for functions returning QAPI lists, then look for callers
>> > interpreting a null value as error.  Would you be willing to do that?
>> >
>> Yes, I would.
>> 
> Hi, Markus
> I have finished this work, and not found this kind of error. :)

Thanks!