svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

[Andrey Chernov]

On 29.08.2016 21:16, Andrey Chernov wrote:
> On 29.08.2016 21:04, Konstantin Belousov wrote:
>> On Mon, Aug 29, 2016 at 08:46:47PM +0300, Andrey Chernov wrote:
>>> Either we implement this wrapper or left all things as is, we need to
>>> document internal errno clearing additionally, to not make people wonder
>>> why errno becomes 0, probably with the mention that program should not
>>> relay on this obsoleted implementation feature.
>> It was done in r304928.  John want to revert this change, it seems.
>>
> Previous text is documented everywhere and describing usual good
> practice, so it should remains in place, in that means r304928 should be
> reverted, because replace proper way of doing things with obsoleted
> feature description.
> 
> What I suggest is not _replace_ old text with new, but _add_ new text as
> describing current and not recommended way, with the direct mention that
> this feature is obsoleted and not recommended for relay on it.

I.e. add to old text something like this (my English is bad, so it
probably needs correction):
"Currently ptrace(2) always set errno to 0 at the start, but portable
program should not relay on this obsoleted feature".