1 files changed, 15 insertions, 0 deletions
diff --git a/tests/ui/borrowck/two-phase-sneaky.rs b/tests/ui/borrowck/two-phase-sneaky.rs
new file mode 100644
index 000000000..bf06366de
--- /dev/null
+++ b/tests/ui/borrowck/two-phase-sneaky.rs
@@ -0,0 +1,15 @@
+// This is the first counter-example from Niko's blog post
+// smallcultfollowing.com/babysteps/blog/2017/03/01/nested-method-calls-via-two-phase-borrowing/
+// of a danger for code to crash if we just turned off the check for whether
+// a mutable-borrow aliases another borrow.
+
+fn main() {
+    let mut v: Vec<String> = vec![format!("Hello, ")];
+    v[0].push_str({
+
+        v.push(format!("foo"));
+        //~^   ERROR cannot borrow `v` as mutable more than once at a time [E0499]
+
+        "World!"
+    });
+}