1 files changed, 28 insertions, 0 deletions

diff --git a/tests/ui/issues/issue-18783.rs b/tests/ui/issues/issue-18783.rs
new file mode 100644
index 00000000000..d4851ac1418
--- /dev/null
+++ b/tests/ui/issues/issue-18783.rs
@@ -0,0 +1,28 @@
+use std::cell::RefCell;
+
+fn main() {
+    let mut y = 1;
+    let c = RefCell::new(vec![]);
+    c.push(Box::new(|| y = 0));
+    c.push(Box::new(|| y = 0));
+//~^ ERROR cannot borrow `y` as mutable more than once at a time
+}
+
+fn ufcs() {
+    let mut y = 1;
+    let c = RefCell::new(vec![]);
+
+    Push::push(&c, Box::new(|| y = 0));
+    Push::push(&c, Box::new(|| y = 0));
+//~^ ERROR cannot borrow `y` as mutable more than once at a time
+}
+
+trait Push<'c> {
+    fn push<'f: 'c>(&self, push: Box<dyn FnMut() + 'f>);
+}
+
+impl<'c> Push<'c> for RefCell<Vec<Box<dyn FnMut() + 'c>>> {
+    fn push<'f: 'c>(&self, fun: Box<dyn FnMut() + 'f>) {
+        self.borrow_mut().push(fun)
+    }
+}