Fix unsafe usage of strerror(errno) within ereport().

This is the converse of the unsafe-usage-of-%m problem: the reason
ereport/elog provide that format code is mainly to dodge the hazard
of errno getting changed before control reaches functions within the
arguments of the macro.  I only found one instance of this hazard,
but it's been there since 9.4 :-(.
This commit is contained in:
Tom Lane 2018-05-21 00:32:28 -04:00
parent 9c515f77d6
commit 1545ca9a74

View File

@ -1752,10 +1752,12 @@ auth_peer(hbaPort *port)
pw = getpwuid(uid);
if (!pw)
{
int save_errno = errno;
ereport(LOG,
(errmsg("could not look up local user ID %ld: %s",
(long) uid,
errno ? strerror(errno) : _("user does not exist"))));
save_errno ? strerror(save_errno) : _("user does not exist"))));
return STATUS_ERROR;
}