1 files changed, 42 insertions, 0 deletions
diff --git a/src/test/ui/borrowck/borrowck-scope-of-deref-issue-4666.rs b/src/test/ui/borrowck/borrowck-scope-of-deref-issue-4666.rs
new file mode 100644
index 000000000..e89332ae3
--- /dev/null
+++ b/src/test/ui/borrowck/borrowck-scope-of-deref-issue-4666.rs
@@ -0,0 +1,42 @@
+// run-pass
+// Tests that the scope of the pointer returned from `get()` is
+// limited to the deref operation itself, and does not infect the
+// block as a whole.
+
+
+struct Box {
+    x: usize
+}
+
+impl Box {
+    fn get(&self) -> &usize {
+        &self.x
+    }
+    fn set(&mut self, x: usize) {
+        self.x = x;
+    }
+}
+
+fn fun1() {
+    // in the past, borrow checker behaved differently when
+    // init and decl of `v` were distinct
+    let v;
+    let mut a_box = Box {x: 0};
+    a_box.set(22);
+    v = *a_box.get();
+    a_box.set(v+1);
+    assert_eq!(23, *a_box.get());
+}
+
+fn fun2() {
+    let mut a_box = Box {x: 0};
+    a_box.set(22);
+    let v = *a_box.get();
+    a_box.set(v+1);
+    assert_eq!(23, *a_box.get());
+}
+
+pub fn main() {
+    fun1();
+    fun2();
+}