From 180b3497215dd4e3da5b214d03286823e63f7bdb Mon Sep 17 00:00:00 2001
From: Elliott Pierce <elliottjpierce2005@gmail.com>
Date: Sat, 31 May 2025 17:49:13 -0400
Subject: [PATCH] all destructs increment the generation

---
 crates/bevy_ecs/src/entity/map_entities.rs |  9 ++++++---
 crates/bevy_ecs/src/world/entity_ref.rs    | 10 +++++-----
 crates/bevy_ecs/src/world/mod.rs           | 14 --------------
 3 files changed, 11 insertions(+), 22 deletions(-)

diff --git a/crates/bevy_ecs/src/entity/map_entities.rs b/crates/bevy_ecs/src/entity/map_entities.rs
index 883095933b..75526868d4 100644
--- a/crates/bevy_ecs/src/entity/map_entities.rs
+++ b/crates/bevy_ecs/src/entity/map_entities.rs
@@ -299,9 +299,12 @@ impl<'m> SceneEntityMapper<'m> {
     /// safely allocate any more references, this method takes ownership of `self` in order to render it unusable.
     pub fn finish(self, world: &mut World) {
         // SAFETY: We never constructed the entity and never released it for something else to construct.
-        unsafe {
-            world.release_generations_unchecked(self.dead_start.row(), self.generations);
-        }
+        let reuse_row = unsafe {
+            world
+                .entities
+                .mark_free(self.dead_start.row(), self.generations)
+        };
+        world.allocator.free(reuse_row);
     }
 
     /// Creates an [`SceneEntityMapper`] from a provided [`World`] and [`EntityHashMap<Entity>`], then calls the
diff --git a/crates/bevy_ecs/src/world/entity_ref.rs b/crates/bevy_ecs/src/world/entity_ref.rs
index e047ead152..6dec064703 100644
--- a/crates/bevy_ecs/src/world/entity_ref.rs
+++ b/crates/bevy_ecs/src/world/entity_ref.rs
@@ -2373,6 +2373,7 @@ impl<'w> EntityWorldMut<'w> {
 
     /// Destructs the entity, without releasing it.
     /// This may be later [`constructed`](Self::construct).
+    /// Note that this still increases the generation to differentiate different constructions of the same row.
     #[track_caller]
     pub fn destruct(&mut self) -> &mut Self {
         self.destruct_with_caller(MaybeLocation::caller())
@@ -2517,7 +2518,10 @@ impl<'w> EntityWorldMut<'w> {
         }
 
         // finish
+        // SAFETY: We just destructed it.
+        self.entity = unsafe { self.world.entities.mark_free(self.entity.row(), 1) };
         self.world.flush();
+        self.update_location(); // In case some command re-constructs this entity.
         self
     }
 
@@ -2536,11 +2540,7 @@ impl<'w> EntityWorldMut<'w> {
 
     pub(crate) fn despawn_with_caller(mut self, caller: MaybeLocation) {
         self.destruct_with_caller(caller);
-        // SAFETY: We just destructed.
-        unsafe {
-            self.world
-                .release_generations_unchecked(self.entity.row(), 1);
-        }
+        self.world.allocator.free(self.entity);
     }
 
     /// Ensures any commands triggered by the actions of Self are applied, equivalent to [`World::flush`]
diff --git a/crates/bevy_ecs/src/world/mod.rs b/crates/bevy_ecs/src/world/mod.rs
index f745e1fb43..dd33e2f89b 100644
--- a/crates/bevy_ecs/src/world/mod.rs
+++ b/crates/bevy_ecs/src/world/mod.rs
@@ -1553,20 +1553,6 @@ impl World {
         Ok(entity)
     }
 
-    /// Releases `entity` to be reused.
-    ///
-    /// # Safety
-    ///
-    /// It must have been destructed.
-    pub(crate) unsafe fn release_generations_unchecked(
-        &mut self,
-        entity: EntityRow,
-        generations: u32,
-    ) {
-        self.allocator
-            .free(self.entities.mark_free(entity, generations));
-    }
-
     /// Clears the internal component tracker state.
     ///
     /// The world maintains some internal state about changed and removed components. This state