Add cfulist_delete_data

It is important to let the programmer remove a node from the linked list, as it is a very common operation.

doc/libcfu.texi

@@ -509,6 +509,11 @@ cfulist_map().  The return value is used to build a new list.
  Pop a value from the end of the list (removing it from the list).
 @end deftypefun
 
+@deftypefun void cfulist_delete_data (cfulist_t * @var{list}, void * @var{data})
+
+ Deletes the entry in the list associated with value.
+@end deftypefun
+
 @deftypefun {int} cfulist_unshift_data (cfulist_t * @var{list}, void * @var{data}, size_t @var{data_size})
 
  Add a value at the beginning of the list. 

src/cfulist.c

@@ -412,6 +412,28 @@ cfulist_pop(cfulist_t *list) {
 	return NULL;
 }
 
+void
+cfulist_delete_data(cfulist_t *list, void *data) {
+	cfulist_entry *ptr = NULL;
+
+	if (!list) {
+		return;
+	}
+
+	lock_list(list);
+
+	if (list->entries) {
+		for (ptr = list->entries; ptr && ptr->data != data; ptr = ptr->next)
+		;
+		if (ptr && ptr->data == data) {
+			(ptr->prev)->next = ptr->next;
+			free (ptr);
+		}
+	}
+
+	unlock_list(list);
+}
+
 int
 cfulist_unshift(cfulist_t *list, void *data) {
 	return cfulist_unshift_data(list, data, 0);

src/cfulist.h

@@ -81,6 +81,9 @@ int cfulist_push_data(cfulist_t *list, void *data, size_t data_size);
 /* Pop a value from the end of the list. */
 int cfulist_pop_data(cfulist_t *list, void **data, size_t *data_size);
 
+/* Deletes the entry in the list associated with value. */
+void cfulist_delete_data(cfulist_t *list, void *data);
+
 /* Add a value at the beginning of the list. */
 int cfulist_unshift_data(cfulist_t *list, void *data, size_t data_size);