[PATCH] posix: Fix posix_spawnpi to not execute invalid binaries in non compat mode (BZ#23264)

[Adhemerval Zanella]

On 06/06/2018 15:20, Florian Weimer wrote:
> On 06/06/2018 08:11 PM, Adhemerval Zanella wrote:
>> Current posix_spawnp implementation wrongly tries to execute invalid
>> binaries (for instance script without shebang) as a shell script in
>> non compat mode.  It was a regression introduced by
>> 9ff72da471a509a8c19791efe469f47fa6977410 when __spawni started to use
>> __execvpe instead of __execve (glibc __execvpe try to execute ENOEXEC
>> as shell script regardless).
>>
>> This patch fixes it by using an internal symbol (__execvpex) with the
>> faulty semantic (since compat mode is handled by spawni.c itself).
> 
> Why doesn't this need a new compatibility symbol, similar to the previously attempted change?

Should we handle regressions in such way? My intention is to backport it
to previous versions as well.