tal: make sure tal_free() preserves errno.

[ccan] / ccan / tal / tal.c

diff --git a/ccan/tal/tal.c b/ccan/tal/tal.c
index 612c67bb833f65de486a3c0d534487efc761d85e..f33a069a4bf49af63932350aa236b513cfc912e4 100644 (file)
--- a/ccan/tal/tal.c
+++ b/ccan/tal/tal.c
@@ -9,6 +9,7 @@
 #include <stddef.h>
 #include <string.h>
 #include <limits.h>
+#include <errno.h>
 
 //#define TAL_DEBUG 1
 
@@ -294,6 +295,7 @@ static struct children *add_child_property(struct tal_hdr *parent,
 
                init_group_property(&prop->group, prop, child);
                list_head_init(&prop->group.list);
+               update_bounds(&prop->group);
        }
        return prop;
 }
@@ -316,8 +318,7 @@ static bool add_child(struct tal_hdr *parent, struct tal_hdr *child)
                children = add_child_property(parent, child);
                if (!children)
                        return false;
-               children->group.list.n.next = children->group.list.n.prev
-                       = &children->group.list.n;
+               list_head_init(&children->group.list);
 
                /* Child links to itself. */
                 child->next = child;
@@ -455,6 +456,7 @@ static struct tal_hdr *remove_node(struct tal_hdr *t)
 
                /* Are we the only one? */
                if (prev == t) {
+                       struct prop_hdr *next = (*prop)->next;
                        struct children *c = group->parent_child;
                        /* Is this the group embedded in the child property? */
                        if (group == &c->group) {
@@ -462,9 +464,9 @@ static struct tal_hdr *remove_node(struct tal_hdr *t)
                        } else {
                                /* Empty group, so free it. */
                                list_del_from(&c->group.list, &group->list.n);
-                               *prop = group->hdr.next;
                                freefn(group);
                        }
+                       *prop = next;
                        return c->parent;
                } else {
                        /* Move property to next node. */
@@ -481,6 +483,7 @@ static struct tal_hdr *remove_node(struct tal_hdr *t)
 void tal_free(const tal_t *ctx)
 {
         struct tal_hdr *t;
+       int saved_errno = errno;
 
         if (!ctx)
                 return;
@@ -488,6 +491,7 @@ void tal_free(const tal_t *ctx)
         t = debug_tal(to_tal_hdr(ctx));
         remove_node(t);
         del_tree(t);
+       errno = saved_errno;
 }
 
 void *tal_steal_(const tal_t *new_parent, const tal_t *ctx)
@@ -638,7 +642,12 @@ tal_t *tal_next(const tal_t *root, const tal_t *prev)
 tal_t *tal_parent(const tal_t *ctx)
 {
         struct group *group;
-        struct tal_hdr *t = debug_tal(to_tal_hdr(ctx));
+        struct tal_hdr *t;
+
+       if (!ctx)
+               return NULL;
+
+       t = debug_tal(to_tal_hdr(ctx));
 
        while (!(group = find_property(t, GROUP)))
                t = t->next;
@@ -887,7 +896,8 @@ static bool check_node(struct group *group,
                        name = (struct name *)p;
                        break;
                }
-               if (p != &null_parent.c.hdr && !in_bounds(p))
+               if (p != &null_parent.c.hdr && p != &null_parent.c.group.hdr
+                   && !in_bounds(p))
                        return check_err(t, errorstr,
                                         "has bad property pointer");