[perl #124160] Disable targlex for state var init

The targlex optimisation optimises away an assignment to a lexical
variable, having the operator on the rhs write directly to the lexi-
cal itself.  This optimisation has a bug in it (#101640) that causes
$lex = "a $b c" to stringify the result, instead of allowing con-
cat overloding to return something other than a string.  I extended
the optimisation to occur with state variable initialization, in
v5.21.5-366-ga1b22ab, not realising it would make an existing bug
occur more often.  For now, just disable the new optimisation.

1 files changed, 3 insertions, 0 deletions

diff --git a/op.c b/op.c
index a07eb05292..89bf436969 100644
--- a/op.c
+++ b/op.c
@@ -10476,7 +10476,10 @@ Perl_ck_sassign(pTHX_ OP *o)
 				    | ((kkid->op_private & ~OPpLVAL_INTRO) << 8));
 	    OP *const first = newOP(OP_NULL, 0);
 	    OP *const nullop =
+		newCONDOP(0, first, o, other);
+	    /* XXX targlex disabled for now; see ticket #124160
 		newCONDOP(0, first, S_maybe_targlex(aTHX_ o), other);
+	     */
 	    OP *const condop = first->op_next;
 
             OpTYPE_set(condop, OP_ONCE);