fix typo

[rust.git] / library / alloc / src / collections / vec_deque / mod.rs

diff --git a/library/alloc/src/collections/vec_deque/mod.rs b/library/alloc/src/collections/vec_deque/mod.rs
index 57807bc54539031f1044064c9d4570c14e2a484d..9e54c15ea6a0b3a5f2bfed00d985187600801889 100644 (file)
--- a/library/alloc/src/collections/vec_deque/mod.rs
+++ b/library/alloc/src/collections/vec_deque/mod.rs
@@ -2793,8 +2793,12 @@ fn from(other: Vec<T>) -> Self {
             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 two 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)
             {