Fix leak in panic_while_overwriting_component test

bevyengine · Jul 1, 2022 · 960a7a8 · 960a7a8
1 parent bcdd93a
commit 960a7a8
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Showing 2 changed files with 13 additions and 0 deletions.
diff --git a/crates/bevy_ecs/src/storage/blob_vec.rs b/crates/bevy_ecs/src/storage/blob_vec.rs
@@ -151,8 +151,20 @@ impl BlobVec {
         let ptr = self.get_unchecked_mut(index).promote().as_ptr();
         self.len = 0;
         // Drop the old value, then write back, justifying the promotion
+        // If the drop impl for the old value panics then we run the drop impl for `value` too.
         if let Some(drop) = self.drop {
+            struct OnDrop<F: FnMut()>(F);
+            impl<F: FnMut()> Drop for OnDrop<F> {
+                fn drop(&mut self) {
+                    (self.0)();
+                }
+            }
+            let value = value.as_ptr();
+            let on_unwind = OnDrop(|| (drop)(OwningPtr::new(NonNull::new_unchecked(value))));
+
             (drop)(OwningPtr::new(NonNull::new_unchecked(ptr)));
+
+            core::mem::forget(on_unwind);
         }
         std::ptr::copy_nonoverlapping::<u8>(value.as_ptr(), ptr, self.item_layout.size());
         self.len = old_len;

diff --git a/crates/bevy_ecs/src/world/mod.rs b/crates/bevy_ecs/src/world/mod.rs
@@ -1693,6 +1693,7 @@ mod tests {
                 DropLogItem::Create(0),
                 DropLogItem::Create(1),
                 DropLogItem::Drop(0),
+                DropLogItem::Drop(1),
             ]
         );
     }