1 files changed, 16 insertions, 0 deletions
diff --git a/tests/ui/regions/regions-reborrow-from-shorter-mut-ref.rs b/tests/ui/regions/regions-reborrow-from-shorter-mut-ref.rs
new file mode 100644
index 000000000..88cc54650
--- /dev/null
+++ b/tests/ui/regions/regions-reborrow-from-shorter-mut-ref.rs
@@ -0,0 +1,16 @@
+// Issue #8624. Tests that reborrowing the contents of an `&'b mut`
+// pointer which is backed by another `&'a mut` can only be done
+// for `'a` (which must be a sublifetime of `'b`).
+
+fn copy_borrowed_ptr<'a, 'b>(p: &'a mut &'b mut isize) -> &'b mut isize {
+    &mut **p
+    //~^ ERROR lifetime may not live long enough
+}
+
+fn main() {
+    let mut x = 1;
+    let mut y = &mut x;
+    let z = copy_borrowed_ptr(&mut y);
+    *y += 1;
+    *z += 1;
+}