1 files changed, 22 insertions, 0 deletions

diff --git a/tests/ui/issues/issue-34349.rs b/tests/ui/issues/issue-34349.rs
new file mode 100644
index 000000000..d86180261
--- /dev/null
+++ b/tests/ui/issues/issue-34349.rs
@@ -0,0 +1,22 @@
+// This is a regression test for a problem encountered around upvar
+// inference and trait caching: in particular, we were entering a
+// temporary closure kind during inference, and then caching results
+// based on that temporary kind, which led to no error being reported
+// in this particular test.
+
+fn main() {
+    let inc = || {};
+    inc();
+
+    fn apply<F>(f: F) where F: Fn() {
+        f()
+    }
+
+    let mut farewell = "goodbye".to_owned();
+    let diary = || { //~ ERROR E0525
+        farewell.push_str("!!!");
+        println!("Then I screamed {}.", farewell);
+    };
+
+    apply(diary);
+}