From 4392b983b8e765a25c7bf081c06e8ecc37425274 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 14 Feb 2023 13:42:03 +0100
Subject: [PATCH] mempool: make mempool_free_tile() return NULL

To match how we usually do this current allocation code.

(Also, make it accept a NULL pointer, also in order to match behaviour
in the rest of our codebase)
---
 src/basic/mempool.c | 11 +++++++++--
 src/basic/mempool.h |  2 +-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/basic/mempool.c b/src/basic/mempool.c
index d934aa9547..999b86d5cb 100644
--- a/src/basic/mempool.c
+++ b/src/basic/mempool.c
@@ -70,9 +70,16 @@ void* mempool_alloc0_tile(struct mempool *mp) {
         return p;
 }
 
-void mempool_free_tile(struct mempool *mp, void *p) {
-        * (void**) p = mp->freelist;
+void* mempool_free_tile(struct mempool *mp, void *p) {
+        assert(mp);
+
+        if (!p)
+                return NULL;
+
+        *(void**) p = mp->freelist;
         mp->freelist = p;
+
+        return NULL;
 }
 
 void mempool_drop(struct mempool *mp) {
diff --git a/src/basic/mempool.h b/src/basic/mempool.h
index 134e6cab17..6680ba3a9b 100644
--- a/src/basic/mempool.h
+++ b/src/basic/mempool.h
@@ -15,7 +15,7 @@ struct mempool {
 
 void* mempool_alloc_tile(struct mempool *mp);
 void* mempool_alloc0_tile(struct mempool *mp);
-void mempool_free_tile(struct mempool *mp, void *p);
+void* mempool_free_tile(struct mempool *mp, void *p);
 
 #define DEFINE_MEMPOOL(pool_name, tile_type, alloc_at_least) \
 static struct mempool pool_name = { \