Fix TinyVec::drain implementation

Cargo.toml

@@ -32,3 +32,7 @@ all-features = true
 
 [workspace]
 members = ["fuzz"]
+
+[[test]]
+name = "tinyvec"
+required-features = ["extern_crate_alloc"]

src/tiny_vec.rs

@@ -215,8 +215,8 @@ impl<A: Arrayish> TinyVec<A> {
       Bound::Unbounded => 0,
     };
     let end = match range.end_bound() {
-      Bound::Included(x) => *x,
-      Bound::Excluded(x) => x - 1,
+      Bound::Included(x) => x + 1,
+      Bound::Excluded(x) => *x,
       Bound::Unbounded => self.len(),
     };
     assert!(

tests/tinyvec.rs

@@ -0,0 +1,33 @@
+#![allow(bad_style)]
+
+use tinyvec::*;
+use std::iter::FromIterator;
+
+#[test]
+fn TinyVec_drain() {
+  let mut tv: TinyVec<[i32; 10]> = Default::default();
+  tv.push(1);
+  tv.push(2);
+  tv.push(3);
+
+  assert_eq!(Vec::from_iter(tv.clone().drain(..)), vec![1, 2, 3]);
+
+  assert_eq!(Vec::from_iter(tv.clone().drain(..2)), vec![1, 2]);
+  assert_eq!(Vec::from_iter(tv.clone().drain(..3)), vec![1, 2, 3]);
+
+  assert_eq!(Vec::from_iter(tv.clone().drain(..=1)), vec![1, 2]);
+  assert_eq!(Vec::from_iter(tv.clone().drain(..=2)), vec![1, 2, 3]);
+
+  assert_eq!(Vec::from_iter(tv.clone().drain(0..)), vec![1, 2, 3]);
+  assert_eq!(Vec::from_iter(tv.clone().drain(1..)), vec![2, 3]);
+
+  assert_eq!(Vec::from_iter(tv.clone().drain(0..2)), vec![1, 2]);
+  assert_eq!(Vec::from_iter(tv.clone().drain(0..3)), vec![1, 2, 3]);
+  assert_eq!(Vec::from_iter(tv.clone().drain(1..2)), vec![2]);
+  assert_eq!(Vec::from_iter(tv.clone().drain(1..3)), vec![2, 3]);
+
+  assert_eq!(Vec::from_iter(tv.clone().drain(0..=1)), vec![1, 2]);
+  assert_eq!(Vec::from_iter(tv.clone().drain(0..=2)), vec![1, 2, 3]);
+  assert_eq!(Vec::from_iter(tv.clone().drain(1..=1)), vec![2]);
+  assert_eq!(Vec::from_iter(tv.clone().drain(1..=2)), vec![2, 3]);
+}