signatures: don't leak an OP_NULL for a '$ =' sigscalarelem

tonycoz · tonycoz · commit 4c09c43e5ba8 · 2025-04-10T15:03:30.000+10:00
Fixes #23187
diff --git a/op.c b/op.c
@@ -16550,6 +16550,9 @@ Perl_subsignature_append_positional(pTHX_ OP *varop, OPCODE defmode, OP *defexpr
 
         if(defexpr->op_type == OP_NULL && !(defexpr->op_flags & OPf_KIDS))
         {
+            /* newOP(OP_NULL, 0) in the caller */
+            op_free(defexpr);
+
             /* handle '$=' special case */
             if(varop)
                 yyerror("Optional parameter lacks default expression");

Original file line number	Diff line number	Diff line change
`@@ -16550,6 +16550,9 @@ Perl_subsignature_append_positional(pTHX_ OP varop, OPCODE defmode, OP defexpr`
`16550`	`16550`
`16551`	`16551`	`if(defexpr->op_type == OP_NULL && !(defexpr->op_flags & OPf_KIDS))`
`16552`	`16552`	`{`
	`16553`	`+ /* newOP(OP_NULL, 0) in the caller */`
	`16554`	`+ op_free(defexpr);`
	`16555`	`+`
`16553`	`16556`	`/* handle '$=' special case */`
`16554`	`16557`	`if(varop)`
`16555`	`16558`	`yyerror("Optional parameter lacks default expression");`