From 1965029cb08ed31aca48921bd0418033cc0b060a Mon Sep 17 00:00:00 2001
From: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Date: Tue, 6 Dec 2011 00:47:06 -0200
Subject: [PATCH] kmod_list: add helper function to merge two lists

This helper function will append the second list in the first one, so
they become one single list.
---
 libkmod/libkmod-list.c    | 31 +++++++++++++++++++++++++++++++
 libkmod/libkmod-private.h |  1 +
 2 files changed, 32 insertions(+)

diff --git a/libkmod/libkmod-list.c b/libkmod/libkmod-list.c
index 2b7fc54d..a2978538 100644
--- a/libkmod/libkmod-list.c
+++ b/libkmod/libkmod-list.c
@@ -99,6 +99,26 @@ static inline void list_node_insert_before(struct list_node *list,
 	list->prev = node;
 }
 
+static inline void list_node_append_list(struct list_node *list1,
+							struct list_node *list2)
+{
+	struct list_node *list1_last;
+
+	if (list1 == NULL) {
+		list_node_init(list2);
+		return;
+	}
+
+	list1->prev->next = list2;
+	list2->prev->next = list1;
+
+	/* cache the last, because we will lose the pointer */
+	list1_last = list1->prev;
+
+	list1->prev = list2->prev;
+	list2->prev = list1_last;
+}
+
 struct kmod_list *kmod_list_append(struct kmod_list *list, const void *data)
 {
 	struct kmod_list *new;
@@ -147,6 +167,17 @@ struct kmod_list *kmod_list_insert_before(struct kmod_list *list, const void *da
 	return new;
 }
 
+struct kmod_list *kmod_list_append_list(struct kmod_list *list1,
+						struct kmod_list *list2)
+{
+	if (list1 == NULL)
+		return list2;
+
+	list_node_append_list(&list1->node, &list2->node);
+
+	return list1;
+}
+
 struct kmod_list *kmod_list_prepend(struct kmod_list *list, const void *data)
 {
 	struct kmod_list *new;
diff --git a/libkmod/libkmod-private.h b/libkmod/libkmod-private.h
index 8e9e540f..5479cc95 100644
--- a/libkmod/libkmod-private.h
+++ b/libkmod/libkmod-private.h
@@ -55,6 +55,7 @@ struct kmod_list *kmod_list_remove_n_latest(struct kmod_list *list,
 						unsigned int n) __must_check;
 struct kmod_list *kmod_list_insert_after(struct kmod_list *list, const void *data) __attribute__((nonnull(2)));
 struct kmod_list *kmod_list_insert_before(struct kmod_list *list, const void *data) __attribute__((nonnull(2)));
+struct kmod_list *kmod_list_append_list(struct kmod_list *list1, struct kmod_list *list2) __must_check;
 
 #undef kmod_list_foreach
 #define kmod_list_foreach(list_entry, first_entry) \
-- 
2.47.2