[PATCH] tst-fopen-threaded: Only check EOF for failing read

[Siddhesh Poyarekar]

On 2025-03-14 11:29, Florian Weimer wrote:
> * Siddhesh Poyarekar:
> 
>>> You don't mention anywhere why you remove the clearerr call?  I think
>>> that's necessary because the test assumes that feof is sticky.
>>
>> Would it change the outcome though?  If there are multiple failing
>> readers, they would reliably result in the test failing regardless of
>> whether the EOF/error flag is cleared.
> 
> I think you get another race if you leave in the clearerr because a
> reader that sees EOF in fread (0 return) might not observe ot in feof
> because it got reverted by a concurrent clearerr (which clears the EOF
> indicator, too).

Indeed, I hadn't noticed that, thanks.  I'll enhance the comment block 
to add this.

> (By the way, it's not clear from the patch context that ret == 0 is
> correct here, that's because sizeof (read_buffer) is 1 is as well.  So
> the short read scenario cannot really happen.)

I'll enhance the comment to describe this too.

Thanks,
Sid