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

tonycoz · mauke · commit ba2623c8cba6 · 2025-04-19T17:38:59.000+02:00
Fixes #23187
diff --git a/op.c b/op.c
@@ -16551,6 +16551,9 @@ Perl_subsignature_append_positional(pTHX_ OP *varop, OPCODE defmode, OP *defexpr
 
         if(defexpr->op_type == OP_NULL && !(defexpr->op_flags & OPf_KIDS))
         {
+            /* caller passed in newOP(OP_NULL, 0), so we should not leak it */
+            op_free(defexpr);
+
             /* handle '$=' special case */
             if(varop)
                 yyerror("Optional parameter lacks default expression");

Original file line number	Diff line number	Diff line change
`@@ -16551,6 +16551,9 @@ Perl_subsignature_append_positional(pTHX_ OP varop, OPCODE defmode, OP defexpr`
`16551`	`16551`
`16552`	`16552`	`if(defexpr->op_type == OP_NULL && !(defexpr->op_flags & OPf_KIDS))`
`16553`	`16553`	`{`
	`16554`	`+ /* caller passed in newOP(OP_NULL, 0), so we should not leak it */`
	`16555`	`+ op_free(defexpr);`
	`16556`	`+`
`16554`	`16557`	`/* handle '$=' special case */`
`16555`	`16558`	`if(varop)`
`16556`	`16559`	`yyerror("Optional parameter lacks default expression");`