[PATCH 0/3] Fix wrong assumption about errno

[Zack Weinberg]

On Thu, Dec 21, 2017 at 2:54 PM, Aurelien Jarno <aurelien@aurel32.net> wrote:
> These 3 patches fixes the wrong assumption that a successful function
> does not change errno. POSIX explicitly says that applications should
> check errno only after failure (or if the function specification
> provides additional scenarios where it has a defined value).

I like these changes in general, but there are a few specific cases
where functions _are_ guaranteed not to change the value of errno on
success, and application code relies on that.  The one I remember off
the top of my head is the strto* family, where all possible return
values _could_ be the result of a successful parse, so you have to set
errno to 0 beforehand and then check it afterward.  Please make sure
that your changes do not imply this is not the case.

zw