From 9a2aa913c1dd0c23d0e28d2dfa72df9a409b6cd1 Mon Sep 17 00:00:00 2001
From: Alexei Podtelezhnikov <apodtele@gmail.com>
Date: Sat, 14 Mar 2026 10:18:35 -0400
Subject: [PATCH] [cache] Protect referenced nodes.

Delay freeing of referenced noted after FT_Manager_RemoveFaceID.
Fixes #1401.

* src/cache/ftcmanag.c (FTC_Cache_RemoveFaceID): Mark referenced nodes
for later removal.
* src/cache/ftcmanag.c (FTC_Node_Unref): Free unlinked modes.
---
 src/cache/ftccache.c | 10 +++++++---
 src/cache/ftcmanag.c | 20 ++++++++++++++++----
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/src/cache/ftccache.c b/src/cache/ftccache.c
index 28f3f3e7a..4272e0090 100644
--- a/src/cache/ftccache.c
+++ b/src/cache/ftccache.c
@@ -568,9 +568,13 @@
           manager->cur_weight -= cache->clazz.node_weight( node, cache );
           ftc_node_mru_unlink( node, manager );
 
-          cache->clazz.node_free( node, cache );
-
-          cache->slack++;
+          if ( node->ref_count <= 0 )
+          {
+            cache->clazz.node_free( node, cache );
+            cache->slack++;
+          }
+          else
+            node->link = node;  /* mark unlinked */
         }
         else
           pnode = &node->link;
diff --git a/src/cache/ftcmanag.c b/src/cache/ftcmanag.c
index 4c1d85ab1..200c3fe31 100644
--- a/src/cache/ftcmanag.c
+++ b/src/cache/ftcmanag.c
@@ -667,10 +667,22 @@
   FTC_Node_Unref( FTC_Node     node,
                   FTC_Manager  manager )
   {
-    if ( node                                    &&
-         manager                                 &&
-         node->cache_index < manager->num_caches )
-      node->ref_count--;
+    if ( !node || !manager                        ||
+         node->cache_index >= manager->num_caches )
+      return;
+
+    node->ref_count--;
+
+    /* free unlinked node */
+    if ( node->ref_count <= 0 && node->link == node )
+    {
+      FTC_Cache  cache = manager->caches[node->cache_index];
+
+
+      cache->clazz.node_free( node, cache );
+      cache->slack++;
+      ftc_cache_resize( cache );
+    }
   }