From: Hans Kratz <hans@appfour.com>
Date: Mon, 18 Oct 2021 11:15:45 +0000 (+0200)
Subject: Avoid overflow in `VecDeque::with_capacity_in()`.
X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;h=4a37b9cbffdc9ba66e9e4b7a17cb0de157a647f8;p=rust.git

Avoid overflow in `VecDeque::with_capacity_in()`.
---

diff --git a/library/alloc/src/collections/vec_deque/mod.rs b/library/alloc/src/collections/vec_deque/mod.rs
index c890ff4ac5e..de607c8fdab 100644
--- a/library/alloc/src/collections/vec_deque/mod.rs
+++ b/library/alloc/src/collections/vec_deque/mod.rs
@@ -543,9 +543,9 @@ pub fn new_in(alloc: A) -> VecDeque<T, A> {
     /// ```
     #[unstable(feature = "allocator_api", issue = "32838")]
     pub fn with_capacity_in(capacity: usize, alloc: A) -> VecDeque<T, A> {
+        assert!(capacity < 1_usize << usize::BITS - 1, "capacity overflow");
         // +1 since the ringbuffer always leaves one space empty
         let cap = cmp::max(capacity + 1, MINIMUM_CAPACITY + 1).next_power_of_two();
-        assert!(cap > capacity, "capacity overflow");
 
         VecDeque { tail: 0, head: 0, buf: RawVec::with_capacity_in(cap, alloc) }
     }