Auto merge of #70362 - TimDiekmann:alloc-overhaul, r=Amanieu

Overhaul of the `AllocRef` trait to match allocator-wg's latest consens; Take 2

GitHub won't let me reopen #69889 so I make a new PR.

In addition to #69889 this fixes the unsoundness of `RawVec::into_box` when using allocators supporting overallocating. Also it uses `MemoryBlock` in `AllocRef` to unify `_in_place` methods by passing `&mut MemoryBlock`. Additionally, `RawVec` now checks for `size_of::<T>()` again and ignore every ZST. The internal capacity of `RawVec` isn't used by ZSTs anymore, as `into_box` now requires a length to be specified.

r? @Amanieu

fixes rust-lang/wg-allocators#38
fixes rust-lang/wg-allocators#41
fixes rust-lang/wg-allocators#44
fixes rust-lang/wg-allocators#51

1 files changed, 5 insertions, 4 deletions

diff --git a/src/liballoc/collections/btree/node.rs b/src/liballoc/collections/btree/node.rs
index 6ebb98c42cd..11c14299573 100644
--- a/src/liballoc/collections/btree/node.rs
+++ b/src/liballoc/collections/btree/node.rs
@@ -1142,7 +1142,7 @@ impl<'a, K, V> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Internal>, marker::
 
             (*left_node.as_leaf_mut()).len += right_len as u16 + 1;
 
-            if self.node.height > 1 {
+            let layout = if self.node.height > 1 {
                 ptr::copy_nonoverlapping(
                     right_node.cast_unchecked().as_internal().edges.as_ptr(),
                     left_node
@@ -1159,10 +1159,11 @@ impl<'a, K, V> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Internal>, marker::
                         .correct_parent_link();
                 }
 
-                Global.dealloc(right_node.node.cast(), Layout::new::<InternalNode<K, V>>());
+                Layout::new::<InternalNode<K, V>>()
             } else {
-                Global.dealloc(right_node.node.cast(), Layout::new::<LeafNode<K, V>>());
-            }
+                Layout::new::<LeafNode<K, V>>()
+            };
+            Global.dealloc(right_node.node.cast(), layout);
 
             Handle::new_edge(self.node, self.idx)
         }