1 files changed, 13 insertions, 0 deletions
diff --git a/tests/ui/inference/cannot-infer-closure-circular.rs b/tests/ui/inference/cannot-infer-closure-circular.rs
new file mode 100644
index 000000000..affb48149
--- /dev/null
+++ b/tests/ui/inference/cannot-infer-closure-circular.rs
@@ -0,0 +1,13 @@
+fn main() {
+    // Below we call the closure with its own return as the argument, unifying
+    // its inferred input and return types. We want to make sure that the generated
+    // error handles this gracefully, and in particular doesn't generate an extra
+    // note about the `?` operator in the closure body, which isn't relevant to
+    // the inference.
+    let x = |r| { //~ ERROR type annotations needed for `Result<(), E>`
+        let v = r?;
+        Ok(v)
+    };
+
+    let _ = x(x(Ok(())));
+}