From fe29ac9a4411836d9ec84947124411232e52b895 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Wed, 31 Aug 2022 14:21:35 +0200
Subject: [PATCH] fix into_iter on ZST

---
 library/alloc/src/vec/into_iter.rs | 2 +-
 library/alloc/tests/vec.rs         | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/library/alloc/src/vec/into_iter.rs b/library/alloc/src/vec/into_iter.rs
index ed049194dd068..b4157fd589541 100644
--- a/library/alloc/src/vec/into_iter.rs
+++ b/library/alloc/src/vec/into_iter.rs
@@ -266,7 +266,7 @@ impl<T, A: Allocator> DoubleEndedIterator for IntoIter<T, A> {
             None
         } else if mem::size_of::<T>() == 0 {
             // See above for why 'ptr.offset' isn't used
-            self.end = self.ptr.wrapping_byte_sub(1);
+            self.end = self.end.wrapping_byte_sub(1);
 
             // Make up a value of this ZST.
             Some(unsafe { mem::zeroed() })
diff --git a/library/alloc/tests/vec.rs b/library/alloc/tests/vec.rs
index 4c118455a3fc3..f140fc4143f3f 100644
--- a/library/alloc/tests/vec.rs
+++ b/library/alloc/tests/vec.rs
@@ -1104,6 +1104,12 @@ fn test_into_iter_drop_allocator() {
     assert_eq!(drop_count, 2);
 }
 
+#[test]
+fn test_into_iter_zst() {
+    for _ in vec![[0u64; 0]].into_iter() {}
+    for _ in vec![[0u64; 0]; 5].into_iter().rev() {}
+}
+
 #[test]
 fn test_from_iter_specialization() {
     let src: Vec<usize> = vec![0usize; 1];