Re: [Qemu-devel] [PATCH v22 00/25] replace QEMUOptionParameter with QemuOpts

[Eric Blake]

On 03/10/2014 01:31 AM, Chunyan Liu wrote:
> This patch series is to replace QEMUOptionParameter with QemuOpts, so that 
> only
> one Qemu Option structure is kept in QEMU code.

Uggh.  The more I learn about QemuOpts while reviewing this patch, the
more I KNOW it has lurking bugs waiting to bite us.

Case in point:

$ touch oddname,id=1
$ qemu-system-x86_64 -drive id=a,file=oddname,,id=1    # starts
$ # now, swap the two arguments:
$ qemu-system-x86_64 -drive file=oddname,,id=1,id=a
qemu-system-x86_64: -drive file=oddname,,id=1,id=a: Parameter 'id'
expects an identifier
$

Gross.  opts_parse uses strncmp() for checking for a leading 'id=', but
strstr() for checking for an intermediate ',id='.  And strstr() can have
false positives, including in the middle of my filename that was
properly escaped.

This is a long-standing bug - as a bug, you can fix it after freeze, but
as it is long-standing, it's not the end of the world if it misses 2.0.
 But it underscores my plea that this series is not fully baked until
you add a testsuite.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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