Re: [PATCH] qobject: json-streamer: Remove double test

[Eric Blake]

On 4/2/20 8:12 AM, Eric Blake wrote:
> On 4/2/20 7:13 AM, Simran Singhal wrote:
> > Remove the duplicate test "parser->bracket_count >= 0".
> >
> > Signed-off-by: Simran Singhal <address@hidden>
> > ---
> >   qobject/json-streamer.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)

> > (brace > 0 || bracket > 0) && brace >= 0 && bracket >= 0
>
> What I missed was the typo: we checked bracket >= 0 twice, instead of 
> the intended brace >= 0 && bracket >= 0.  This needs a v2.

Effect of the bug:

Note that we can diagnose when we have unbalanced ] with no matching [ 
while inside {}:

$ qemu-kvm --nodefaults --nographic --qmp stdio
{"QMP": {"version": {"qemu": {"micro": 91, "minor": 2, "major": 4}, 
"package": "v5.0.0-rc1-1-gf6ce4a439a08"}, "capabilities": ["oob"]}}
{]
{"error": {"class": "GenericError", "desc": "JSON parse error, expecting 
value"}}

but that we fail to diagnose unbalanced } with no matching { while 
inside []:

[}


--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org