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author | Justus K <justus.k@protonmail.com> | 2020-12-13 10:02:36 +0100 |
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committer | Justus K <justus.k@protonmail.com> | 2020-12-13 10:02:36 +0100 |
commit | 0f30b7dd87b8555698ca7e7de360b037230e1f23 (patch) | |
tree | 0a6cc53e76e38279afb1cc76b00415fd44e81ab4 | |
parent | 7efc097c4fe6e97f54a44cee91c56189e9ddb41c (diff) | |
download | rust-0f30b7dd87b8555698ca7e7de360b037230e1f23.tar.gz |
fix panic if converting ZST Vec to VecDeque
-rw-r--r-- | library/alloc/src/collections/vec_deque/mod.rs | 8 | ||||
-rw-r--r-- | library/alloc/tests/vec_deque.rs | 7 |
2 files changed, 13 insertions, 2 deletions
diff --git a/library/alloc/src/collections/vec_deque/mod.rs b/library/alloc/src/collections/vec_deque/mod.rs index 57807bc5453..1303b58e31c 100644 --- a/library/alloc/src/collections/vec_deque/mod.rs +++ b/library/alloc/src/collections/vec_deque/mod.rs @@ -2793,8 +2793,12 @@ impl<T> From<Vec<T>> for VecDeque<T> { let len = other.len(); // We need to extend the buf if it's not a power of two, too small - // or doesn't have at least one free space - if !buf.capacity().is_power_of_two() + // or doesn't have at least one free space. + // We check if `T` is a ZST in the first condition, + // because `usize::MAX` (the capacity returned by `capacity()` for ZST) + // is not a power of zero and thus it'll always try + // to reserve more memory which will panic for ZST (rust-lang/rust#78532) + if (!buf.capacity().is_power_of_two() && mem::size_of::<T>() != 0) || (buf.capacity() < (MINIMUM_CAPACITY + 1)) || (buf.capacity() == len) { diff --git a/library/alloc/tests/vec_deque.rs b/library/alloc/tests/vec_deque.rs index 705f0d62fbb..a962a5494a9 100644 --- a/library/alloc/tests/vec_deque.rs +++ b/library/alloc/tests/vec_deque.rs @@ -1728,3 +1728,10 @@ fn test_zero_sized_push() { } } } + +#[test] +fn test_from_zero_sized_vec() { + let v = vec![(); 100]; + let queue = VecDeque::from(v); + assert!(queue.len(), 100); +} |