1 files changed, 13 insertions, 0 deletions
diff --git a/src/tools/rustfmt/tests/target/issue_4374.rs b/src/tools/rustfmt/tests/target/issue_4374.rs
new file mode 100644
index 000000000..f5bf657bb
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue_4374.rs
@@ -0,0 +1,13 @@
+fn a<F>(_f: F) -> ()
+where
+    F: FnOnce() -> (),
+{
+}
+fn main() {
+    a(|| {
+        #[allow(irrefutable_let_patterns)]
+        while let _ = 0 {
+            break;
+        }
+    });
+}