1 files changed, 45 insertions, 1 deletions
diff --git a/src/tools/clippy/tests/ui/get_unwrap.rs b/src/tools/clippy/tests/ui/get_unwrap.rs
index 6b1e8edb7..af3a619ad 100644
--- a/src/tools/clippy/tests/ui/get_unwrap.rs
+++ b/src/tools/clippy/tests/ui/get_unwrap.rs
@@ -1,6 +1,11 @@
 //@run-rustfix
 
-#![allow(unused_mut, clippy::from_iter_instead_of_collect, clippy::get_first)]
+#![allow(
+    unused_mut,
+    clippy::from_iter_instead_of_collect,
+    clippy::get_first,
+    clippy::useless_vec
+)]
 #![warn(clippy::unwrap_used)]
 #![deny(clippy::get_unwrap)]
 
@@ -65,3 +70,42 @@ fn main() {
         let _ = some_vec.get_mut(0..1).unwrap().to_vec();
     }
 }
+mod issue9909 {
+    #![allow(clippy::identity_op, clippy::unwrap_used, dead_code)]
+
+    fn reduced() {
+        let f = &[1, 2, 3];
+
+        // include a borrow in the suggestion, even if the argument is not just a numeric literal
+        let _x: &i32 = f.get(1 + 2).unwrap();
+
+        // don't include a borrow here
+        let _x = f.get(1 + 2).unwrap().to_string();
+
+        // don't include a borrow here
+        let _x = f.get(1 + 2).unwrap().abs();
+    }
+
+    // original code:
+    fn linidx(row: usize, col: usize) -> usize {
+        row * 1 + col * 3
+    }
+
+    fn main_() {
+        let mut mat = [1.0f32, 5.0, 9.0, 2.0, 6.0, 10.0, 3.0, 7.0, 11.0, 4.0, 8.0, 12.0];
+
+        for i in 0..2 {
+            for j in i + 1..3 {
+                if mat[linidx(j, 3)] > mat[linidx(i, 3)] {
+                    for k in 0..4 {
+                        let (x, rest) = mat.split_at_mut(linidx(i, k) + 1);
+                        let a = x.last_mut().unwrap();
+                        let b = rest.get_mut(linidx(j, k) - linidx(i, k) - 1).unwrap();
+                        ::std::mem::swap(a, b);
+                    }
+                }
+            }
+        }
+        assert_eq!([9.0, 5.0, 1.0, 10.0, 6.0, 2.0, 11.0, 7.0, 3.0, 12.0, 8.0, 4.0], mat);
+    }
+}