1 files changed, 21 insertions, 0 deletions
diff --git a/src/test/ui/borrowck/borrowck-borrow-of-mut-base-ptr-safe.rs b/src/test/ui/borrowck/borrowck-borrow-of-mut-base-ptr-safe.rs
new file mode 100644
index 000000000..5ef282c0c
--- /dev/null
+++ b/src/test/ui/borrowck/borrowck-borrow-of-mut-base-ptr-safe.rs
@@ -0,0 +1,21 @@
+// run-pass
+#![allow(dead_code)]
+#![allow(unused_mut)]
+#![allow(unused_variables)]
+// Test that freezing an `&mut` pointer while referent is
+// frozen is legal.
+//
+// Example from compiler/rustc_borrowck/borrowck/README.md
+
+// pretty-expanded FIXME #23616
+
+fn foo<'a>(mut t0: &'a mut isize,
+           mut t1: &'a mut isize) {
+    let p: &isize = &*t0; // Freezes `*t0`
+    let mut t2 = &t0;
+    let q: &isize = &**t2; // Freezes `*t0`, but that's ok...
+    let r: &isize = &*t0; // ...after all, could do same thing directly.
+}
+
+pub fn main() {
+}