From: Sebastian Harl <sh@tokkee.org>
Date: Thu, 22 May 2008 11:36:00 +0000 (+0200)
Subject: src/utils_llist.c: Improved robustness against NULL pointers.
X-Git-Tag: collectd-4.4.1~5^2^2~2
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=36f72a66a6b5ad14d7ea67e739fc93633b55d6d3;p=collectd.git

src/utils_llist.c: Improved robustness against NULL pointers.

All functions searching for some list entry now return NULL if the given
list equals NULL. Imho, that's the expected behavior. Also, it removes the
need to check the lists from the calling function while that function
usually checks the returned list entry anyway.

Signed-off-by: Sebastian Harl <sh@tokkee.org>
Signed-off-by: Florian Forster <octo@huhu.verplant.org>
---

diff --git a/src/utils_llist.c b/src/utils_llist.c
index 7fae025d..bf5f7e49 100644
--- a/src/utils_llist.c
+++ b/src/utils_llist.c
@@ -59,6 +59,9 @@ void llist_destroy (llist_t *l)
 	llentry_t *e_this;
 	llentry_t *e_next;
 
+	if (l == NULL)
+		return;
+
 	for (e_this = l->head; e_this != NULL; e_this = e_next)
 	{
 		e_next = e_this->next;
@@ -140,6 +143,9 @@ llentry_t *llist_search (llist_t *l, const char *key)
 {
 	llentry_t *e;
 
+	if (l == NULL)
+		return (NULL);
+
 	for (e = l->head; e != NULL; e = e->next)
 		if (strcmp (key, e->key) == 0)
 			break;
@@ -149,10 +155,14 @@ llentry_t *llist_search (llist_t *l, const char *key)
 
 llentry_t *llist_head (llist_t *l)
 {
+	if (l == NULL)
+		return (NULL);
 	return (l->head);
 }
 
 llentry_t *llist_tail (llist_t *l)
 {
+	if (l == NULL)
+		return (NULL);
 	return (l->tail);
 }