From 70ecb4be2ac4243cbdb6586f87a091a7f8055d91 Mon Sep 17 00:00:00 2001
From: Karl Williamson <khw@cpan.org>
Date: Thu, 7 Mar 2019 11:37:21 -0700
Subject: [PATCH] PATCH: [perl #133899] panic in s///

Thanks for finding this bug, and the others you've been finding.

A new regnode was added, but this function was not updated to account
for that.  I've now checked all the other new regnodes in 5.29 and this
was the only missing one.
---
 regexec.c    | 3 +++
 t/re/subst.t | 7 +++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/regexec.c b/regexec.c
index bb3a630e871a..7cc339a17b51 100644
--- a/regexec.c
+++ b/regexec.c
@@ -4548,6 +4548,9 @@ S_setup_EXACTISH_ST_c1_c2(pTHX_ const regnode * const text_node, int *c1p,
                     case EXACTFU:
                         c2 = PL_fold_latin1[c1];
                         break;
+                    case EXACTFU_ONLY8:
+                        return FALSE;
+                        NOT_REACHED; /* NOTREACHED */
 
                     default:
                         Perl_croak(aTHX_ "panic: Unexpected op %u", OP(text_node));
diff --git a/t/re/subst.t b/t/re/subst.t
index dd62e95ee64f..32076921f50d 100644
--- a/t/re/subst.t
+++ b/t/re/subst.t
@@ -11,7 +11,7 @@ BEGIN {
     require './loc_tools.pl';
 }
 
-plan(tests => 276);
+plan(tests => 277);
 
 $_ = 'david';
 $a = s/david/rules/r;
@@ -1174,5 +1174,8 @@ __EOF__
     is $lines, 4, "RT #131930";
 }
 
+{   # [perl $133899], would panic
 
-
+    fresh_perl_is('my $a = "ha"; $a =~ s!|0?h\x{300}(?{})!!gi', "", {},
+                  "[perl #133899] s!|0?h\\x{300}(?{})!!gi panics");
+}