&CORE::index() and &CORE::rindex()

This commit allows &CORE::index and &CORE::rindex to be called through
references and via ampersand syntax.  pp_index is modified to take
into account the nulls pushed on to the stack in pp_coreargs, which
happens because pp_coreargs has no other way to tell pp_index how many
arguments it’s actually getting.  See commit 0163043a for details.

1 files changed, 3 insertions, 2 deletions

diff --git a/pp.c b/pp.c
index 156c4d36fd..de2b35c2c5 100644
--- a/pp.c
+++ b/pp.c
@@ -3260,8 +3260,9 @@ PP(pp_index)
     bool big_utf8;
     bool little_utf8;
     const bool is_index = PL_op->op_type == OP_INDEX;
+    const bool threeargs = MAXARG >= 3 && (TOPs || ((void)POPs,0));
 
-    if (MAXARG >= 3) {
+    if (threeargs) {
 	/* arybase is in characters, like offset, so combine prior to the
 	   UTF-8 to bytes calculation.  */
 	offset = POPi - arybase;
@@ -3335,7 +3336,7 @@ PP(pp_index)
 	little_p = SvPVX(little);
     }
 
-    if (MAXARG < 3)
+    if (!threeargs)
 	offset = is_index ? 0 : biglen;
     else {
 	if (big_utf8 && offset > 0)