tal: don't defer-after-free if a destructor deletes itself.

[ccan] / ccan / tal / tal.c

diff --git a/ccan/tal/tal.c b/ccan/tal/tal.c
index dff0dcfba2058b0815f79423c0798af9b806fb67..a49541114ff863128dd03a1429fa84c1d4e06ffb 100644 (file)
--- a/ccan/tal/tal.c
+++ b/ccan/tal/tal.c
@@ -53,7 +53,7 @@ struct name {
 struct notifier {
        struct prop_hdr hdr; /* NOTIFIER */
        enum tal_notify_type types;
-       union {
+       union notifier_cb {
                void (*notifyfn)(tal_t *, enum tal_notify_type, void *);
                void (*destroy)(tal_t *); /* If NOTIFY_IS_DESTRUCTOR set */
                void (*destroy2)(tal_t *, void *); /* If NOTIFY_EXTRA_ARG */
@@ -228,11 +228,16 @@ static void notify(const struct tal_hdr *ctx,
                if (n->types & type) {
                        errno = saved_errno;
                        if (n->types & NOTIFY_IS_DESTRUCTOR) {
+                               /* Blatt this notifier in case it tries to
+                                * tal_del_destructor() from inside */
+                               union notifier_cb cb = n->u;
+                               /* It's a union, so this NULLs destroy2 too! */
+                               n->u.destroy = NULL;
                                if (n->types & NOTIFY_EXTRA_ARG)
-                                       n->u.destroy2(from_tal_hdr(ctx),
-                                                     EXTRA_ARG(n));
+                                       cb.destroy2(from_tal_hdr(ctx),
+                                                   EXTRA_ARG(n));
                                else
-                                       n->u.destroy(from_tal_hdr(ctx));
+                                       cb.destroy(from_tal_hdr(ctx));
                        } else
                                n->u.notifyfn(from_tal_hdr_or_null(ctx), type,
                                              (void *)info);