Re: Why does close_stdout close stdout and stderr?

[Florian Weimer]

* Bernhard Voelker:

> On 5/6/19 5:47 PM, Florian Weimer wrote:
>> * Bernhard Voelker:
>>> What is the problem?  I mean if it is use-after-free as mentioned in
>>> the first mail, then write() after fflush() without error checking via
>>> another fflush() is in the same category, isn't it?
>> 
>> No, there is no memory corruption involved because stdout and stderr
>> remain valid.
>
> IMO that's easier to detect than a write() without a following error
> checking; the consequences may also be quite fatal for the user.

I do not understand this comment.  Do you mean fwrite?

How would a programmer check that close_stdout has run, to determine
that stdout and stderr are now invalid, to avoid the memory corruption?

Thanks,
Florian