[PATCH] Don't divide by zero when trying to destroy an uninitialised barrier.

[Florian Weimer]

On 04/20/2016 09:46 PM, Adhemerval Zanella wrote:
> I do not see a compelling reason to not return EINVAL if the UB
> could be detected and if POSIX stated this behaviour is recommended.

It would result in silent loss of synchronization if the return value is 
not checked.  Such bugs are difficult to track down.

Florian