Re: [Qemu-devel] [PATCH for-2.9?] tests/check-qdict: Fix missing brackets

[Eric Blake]

On 04/06/2017 10:49 AM, Eric Blake wrote:
> On 04/06/2017 10:41 AM, Dr. David Alan Gilbert (git) wrote:
>> From: "Dr. David Alan Gilbert" <address@hidden>
>>
>> Gcc 7 (on Fedora 26) spotted odd use of integers instead of a
>> boolean; it's got a point.
>>
>> Signed-off-by: Dr. David Alan Gilbert <address@hidden>
>> ---
>>  tests/check-qdict.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/tests/check-qdict.c b/tests/check-qdict.c
>> index 81162ee572..6f3fbcf9c1 100644
>> --- a/tests/check-qdict.c
>> +++ b/tests/check-qdict.c
>> @@ -559,7 +559,7 @@ static void qdict_join_test(void)
>>          g_assert(qdict_size(dict1) == 2);
>>          g_assert(qdict_size(dict2) == !overwrite);
>>  
>> -        g_assert(qdict_get_int(dict1, "foo") == overwrite ? 84 : 42);
>> +        g_assert(qdict_get_int(dict1, "foo") == (overwrite ? 84 : 42));
> 
> How is the test passing pre-patch, and why does it not change the test
> post-patch?  Does that mean that overwrite is not doing what we expected?

Replying to myself:

Pre-patch, it was reached twice (once for overwrite=false, once for
overwrite=true), as:

(42 == false) ? 84 : 42
(84 == true) ? 84 : 42

which simplifies to 42 on both iterations, and g_assert(42) succeeds.
In fact, this is a tautology - no matter WHAT value we encounter, the
assert succeeds, so we are not actually testing that the value matters.

Post-patch, it becomes:

42 == (false ? 84 : 42)
84 == (true ? 84 : 42)

which is then asserting that we actually have the value we expect.

Reviewed-by: Eric Blake <address@hidden>

Safe for 2.9, but late enough that it also doesn't matter if it slips
until 2.10.

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

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