Avoid leak/crash calling CORE::foo()

The compile time code in Perl_ck_entersub_args_core() that converts a
subroutine call like mypos(1,2) into a direct call to the built-in
function, e.g. pos(1,2), doesn't handle too many args well.
The ops associated with the extra args are excised from the op tree,
but aren't freed, and their op_sigparent pointers aren't updated
correctly.

This is noticeable if op_free() is altered to walk the tree using
op_sigparent to walk back up to the parent.

This commit frees any extra args and emits the 'Too many arguments' error
immediately, rather than tripping over later.

1 files changed, 1 insertions, 1 deletions

diff --git a/t/op/coresubs.t b/t/op/coresubs.t
index 62210b576d..2ee63ef5fc 100644
--- a/t/op/coresubs.t
+++ b/t/op/coresubs.t
@@ -37,7 +37,7 @@ my %args_for = (
   splice   =>)[0,1,2,1,3,1,4,1,5,1],
 );
 my %desc = (
-  pos => 'match position',
+  #pos => 'match position',
 );
 
 use File::Spec::Functions;