[pulseaudio-discuss] [PATCH] Fix test-suite failure on Alpha

[Arun Raghavan]

On 15 September 2015 at 16:46, David Henningsson
<david.henningsson at canonical.com> wrote:
>
> On 2015-09-15 06:45, Arun Raghavan wrote:
>>
>> On 9 September 2015 at 15:19, Michael Cree <mcree at orcon.net.nz> wrote:
>>>
>>> Pulseaudio fails to build on the Alpha architecture due to a failure
>>> in the volume-test of the test suite.  I had reported this to the
>>> Debian bug tracker [1] but the maintainer has asked that I forward the
>>> patch to this mail list.  The failure in volume-test occurs because it
>>> is compiled with -ffast-math which implies -ffinite-math-only of which
>>> the gcc manual states that it optimizes for floating-point arithmetic
>>> with the assumption that arguments and results are not NaNs or
>>> +/-infinity, and futher notes that it may result in incorrect output.
>>> On the Alpha platform that is somewhat an understatement as the use of
>>> non-finite floating-point arithmetic with -ffinite-math-only results in
>>> a floating-point exception and the termination of the program.
>>>
>>> The volume-test converts volumes into decibels (so a zero volume
>>> becomes a negative infinity) and proceeds to add two volumes (in
>>> decibels), thus does arithmetic with non-finite floating point numbers
>>> despite being compiled with -ffast-math!
>>>
>>> I attach a patch that protects against the arithmetic with non-finite
>>> numbers for your consideration.  With that patch the test-suite passes
>>> on Alpha.
>>>
>>> Cheers
>>> Michael.
>>>
>>> [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=798248
>>
>>
>> Thanks for the fix! I've pushed this out to our next branch (since
>> we're frozen for the 7.0 release, it'll only make it out in 8.0).
>
>
> Hi Arun,
>
> Thanks for picking it up, but I think this is a typical example of a bug fix
> that should go in 7.0 even though we're frozen. Not merging it only leads to
> more buggy 7.0 release, and more distro patching for downstreams.

Since this patch is for a test, and is rather trivial, I don't
particularly mind either way.

In general, though, I view each extra patch as a risk of regression
when we are frozen, and as they add up, you start to need to do
another RC, delaying the release. This is why I advocate a stricter
(and thus, imo shorter) freeze period.

-- Arun