reparse compile-time /(?{})/ in right scope

When a compile-time regex like /...(?{ code-block }) .../
is compiled in the presence of constant and concat overloading,
this can cause (still at compile-time) for the pattern to be evaled and
re-compiled, in order to re-compile any code-blocks that got messed up
during the overloading and thus whose text no longer matches that which
the perl parser previously compiled.

When this happens, eval_sv() happens to be called when the perl parser is
still in compiling state; normally its called from running state.
This tickles an undiscovered bug in Perl_find_runcv_where(), which
finds the current cop sequence by looking at PL_curcop->cop_seq.
At compile time, we need to get it from PL_cop_seqmax instead.

1 files changed, 5 insertions, 1 deletions

diff --git a/pp_ctl.c b/pp_ctl.c
index ff3d661a70..1f9432b9f6 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -3274,7 +3274,11 @@ Perl_find_runcv_where(pTHX_ U8 cond, IV arg, U32 *db_seqp)
     int		 level = 0;
 
     if (db_seqp)
-	*db_seqp = PL_curcop->cop_seq;
+	*db_seqp =
+            PL_curcop == &PL_compiling
+                ? PL_cop_seqmax
+                : PL_curcop->cop_seq;
+
     for (si = PL_curstackinfo; si; si = si->si_prev) {
         I32 ix;
 	for (ix = si->si_cxix; ix >= 0; ix--) {