Make keys $scalar an lvalue

This does a run-time check to see whether $scalar is a hash ref, and
dies if it is not.

This is to keep keys \@_ consistent with keys @_.

I cannot simply use OPf_MOD, since that indicates *potential* lvalue
context (including subroutine args).

So, instead, I take advantage of the fact that OPf_SPECIAL is always
set on the LHS of an assignment (usually to indicate that local()
should not erase the value).

1 files changed, 1 insertions, 0 deletions

diff --git a/op.c b/op.c
index f22f888008..e21b9a478f 100644
--- a/op.c
+++ b/op.c
@@ -1690,6 +1690,7 @@ Perl_op_lvalue(pTHX_ OP *o, I32 type)
 	break;
 
     case OP_KEYS:
+    case OP_RKEYS:
 	if (type != OP_SASSIGN)
 	    goto nomod;
 	goto lvalue_func;