[perl #61520] Segfault in debugger with tr// and UTF8

commit 043e41b8 (29765), which made tr// threadsafe by moving the
swash into the pad, didn't mark the pad SV as read-only, so it was getting
removed from anon sub prototypes

1 files changed, 1 insertions, 0 deletions

diff --git a/op.c b/op.c
index 54d2a64a78..d7ef32c3cd 100644
--- a/op.c
+++ b/op.c
@@ -3345,6 +3345,7 @@ S_pmtrans(pTHX_ OP *o, OP *expr, OP *repl)
 	SvREFCNT_dec(PAD_SVl(cPADOPo->op_padix));
 	PAD_SETSV(cPADOPo->op_padix, swash);
 	SvPADTMP_on(swash);
+	SvREADONLY_on(swash);
 #else
 	cSVOPo->op_sv = swash;
 #endif