From 8f23dfa9148967b232ac46318f981aaad01d0d84 Mon Sep 17 00:00:00 2001
From: Alexander Couzens <lynxis@fe80.eu>
Date: Fri, 14 Oct 2022 17:39:47 +0200
Subject: [PATCH] linuxlist: add llist_entry_empty()

Return true if an entry is not included in a llist or
NULL.

Change-Id: Ia4afe3e77f53728db1d139bded5925183dca011f
---
 include/osmocom/core/linuxlist.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/osmocom/core/linuxlist.h b/include/osmocom/core/linuxlist.h
index 2fc3fa75d..398128d97 100644
--- a/include/osmocom/core/linuxlist.h
+++ b/include/osmocom/core/linuxlist.h
@@ -171,6 +171,17 @@ static inline int llist_empty(const struct llist_head *head)
 	return head->next == head;
 }
 
+/*!
+ * Test whether a linked list entry is empty or not included by any list.
+ * \param[in] entry the llist to test
+ * \return 1 if the entry is NULL or not included by any llist.
+ */
+static inline int llist_entry_empty(const struct llist_head *entry)
+{
+	return entry == NULL || (!entry->next && !entry->prev)
+		|| (entry->next == LLIST_POISON1 && entry->prev == LLIST_POISON2);
+}
+
 static inline void __llist_splice(struct llist_head *llist,
 				  struct llist_head *head)
 {