$/ = \-1 will be fatal in Perl 5.28.

Setting $/ to a reference of a non-positive integer has been deprecated
since 5.20, in which it was special cased to act like you had set to
$/ to undef.

In Perl 5.28, setting $/ to a reference to a non-positive integer will
be a fatal error.

1 files changed, 1 insertions, 1 deletions

diff --git a/mg.c b/mg.c
index 1bcfc4f977..8a00dd2541 100644
--- a/mg.c
+++ b/mg.c
@@ -2900,7 +2900,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
                     if (val <= 0) {
                         tmpsv= &PL_sv_undef;
                         Perl_ck_warner_d(aTHX_ packWARN(WARN_DEPRECATED),
-                            "Setting $/ to a reference to %s as a form of slurp is deprecated, treating as undef",
+                            "Setting $/ to a reference to %s as a form of slurp is deprecated, treating as undef. This will be fatal in Perl 5.28",
                             SvIV(SvRV(sv)) < 0 ? "a negative integer" : "zero"
                         );
                     }