use ManuallyDrop in BytesMut#from_vec

src/bytes_mut.rs

@@ -828,11 +828,11 @@ impl BytesMut {
     // internal change could make a simple pattern (`BytesMut::from(vec)`)
     // suddenly a lot more expensive.
     #[inline]
-    pub(crate) fn from_vec(mut vec: Vec<u8>) -> BytesMut {
+    pub(crate) fn from_vec(vec: Vec<u8>) -> BytesMut {
+        let mut vec = ManuallyDrop::new(vec);
         let ptr = vptr(vec.as_mut_ptr());
         let len = vec.len();
         let cap = vec.capacity();
-        mem::forget(vec);
 
         let original_capacity_repr = original_capacity_to_repr(cap);
         let data = (original_capacity_repr << ORIGINAL_CAPACITY_OFFSET) | KIND_VEC;