1 files changed, 20 insertions, 0 deletions
diff --git a/tests/ui/borrowck/borrowck-closures-mut-of-mut.rs b/tests/ui/borrowck/borrowck-closures-mut-of-mut.rs
new file mode 100644
index 000000000..50c6f2c58
--- /dev/null
+++ b/tests/ui/borrowck/borrowck-closures-mut-of-mut.rs
@@ -0,0 +1,20 @@
+// Tests that two closures cannot simultaneously both have mutable
+// access to the variable. Related to issue #6801.
+
+fn get(x: &isize) -> isize {
+    *x
+}
+
+fn set(x: &mut isize) {
+    *x = 4;
+}
+
+fn a(x: &mut isize) {
+    let mut c1 = || set(&mut *x);
+    let mut c2 = || set(&mut *x);
+    //~^ ERROR two closures require unique access to `x` at the same time
+    c2(); c1();
+}
+
+fn main() {
+}