1 files changed, 44 insertions, 0 deletions
diff --git a/src/test/ui/try-block/try-block-maybe-bad-lifetime.rs b/src/test/ui/try-block/try-block-maybe-bad-lifetime.rs
new file mode 100644
index 000000000..cd2ddf63a
--- /dev/null
+++ b/src/test/ui/try-block/try-block-maybe-bad-lifetime.rs
@@ -0,0 +1,44 @@
+// compile-flags: --edition 2018
+
+#![feature(try_blocks)]
+
+#[inline(never)]
+fn do_something_with<T>(_x: T) {}
+
+// This test checks that borrows made and returned inside try blocks are properly constrained
+pub fn main() {
+    {
+        // Test that a borrow which *might* be returned still freezes its referent
+        let mut i = 222;
+        let x: Result<&i32, ()> = try {
+            Err(())?;
+            &i
+        };
+        i = 0; //~ ERROR cannot assign to `i` because it is borrowed
+        let _ = i;
+        do_something_with(x);
+    }
+
+    {
+        let x = String::new();
+        let _y: Result<(), ()> = try {
+            Err(())?;
+            ::std::mem::drop(x);
+        };
+        println!("{}", x); //~ ERROR borrow of moved value: `x`
+    }
+
+    {
+        // Test that a borrow which *might* be assigned to an outer variable still freezes
+        // its referent
+        let mut i = 222;
+        let mut j = &-1;
+        let _x: Result<(), ()> = try {
+            Err(())?;
+            j = &i;
+        };
+        i = 0; //~ ERROR cannot assign to `i` because it is borrowed
+        let _ = i;
+        do_something_with(j);
+    }
+}