[perl #123955] Fix assert fail with 0 s/// in quotes

This is related to bug #123617 and is a follow-up to eabab8bcc.

This code:

"@0{0s 000";eval"$"

begins tokenisation as follows:

stringify ( join ( $ " , @ 0 { 0 subst

When seeing the subst after the 0, the parser discards many tokens and
we end up at the ; outside the quotes.

Since PL_lex_stuff (the temporary spot for storing the contents of a
quote-like operator) is localised as of eabab8bcc, we end up with just
PL_sublex_info.repl (the temporary spot for storing the replacement
part) set.  Since it is still set when we get to the next double-
quote, it is treated as a two-part quote-like operator, like y or s.
That can’t happen, and we have assertions to make sure of it.

We need to localise PL_sublex_info.repl as well, so it gets freed
properly when scopes are popped after an error.

1 files changed, 1 insertions, 0 deletions

diff --git a/toke.c b/toke.c
index f7ad00d063..0eeafd4311 100644
--- a/toke.c
+++ b/toke.c
@@ -2381,6 +2381,7 @@ S_sublex_push(pTHX)
        popping.  We must not have a PL_lex_stuff value left dangling, as
        that breaks assumptions elsewhere.  See bug #123617.  */
     SAVEGENERICSV(PL_lex_stuff);
+    SAVEGENERICSV(PL_sublex_info.repl);
 
     PL_bufend = PL_bufptr = PL_oldbufptr = PL_oldoldbufptr = PL_linestart
 	= SvPVX(PL_linestr);