2 files changed, 50 insertions, 0 deletions
diff --git a/tests/ui/recursion/recursive-impl-trait-iterator-by-ref-67552.rs b/tests/ui/recursion/recursive-impl-trait-iterator-by-ref-67552.rs
new file mode 100644
index 00000000000..0875d385ddc
--- /dev/null
+++ b/tests/ui/recursion/recursive-impl-trait-iterator-by-ref-67552.rs
@@ -0,0 +1,33 @@
+//@ build-fail
+//@ compile-flags: -Copt-level=0
+
+fn main() {
+    rec(Empty);
+}
+
+struct Empty;
+
+impl Iterator for Empty {
+    type Item = ();
+    fn next<'a>(&'a mut self) -> core::option::Option<()> {
+        None
+    }
+}
+
+fn identity<T>(x: T) -> T {
+    x
+}
+
+fn rec<T>(mut it: T)
+where
+    T: Iterator,
+{
+    if () == () {
+        T::count(it);
+    } else {
+        rec(identity(&mut it))
+        //~^ ERROR reached the recursion limit while instantiating
+    }
+}
+
+// https://github.com/rust-lang/rust/issues/67552
diff --git a/tests/ui/recursion/recursive-impl-trait-iterator-by-ref-67552.stderr b/tests/ui/recursion/recursive-impl-trait-iterator-by-ref-67552.stderr
new file mode 100644
index 00000000000..fe005984fab
--- /dev/null
+++ b/tests/ui/recursion/recursive-impl-trait-iterator-by-ref-67552.stderr
@@ -0,0 +1,17 @@
+error: reached the recursion limit while instantiating `rec::<&mut &mut &mut &mut &mut ...>`
+  --> $DIR/recursive-impl-trait-iterator-by-ref-67552.rs:28:9
+   |
+LL |         rec(identity(&mut it))
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: `rec` defined here
+  --> $DIR/recursive-impl-trait-iterator-by-ref-67552.rs:21:1
+   |
+LL | / fn rec<T>(mut it: T)
+LL | | where
+LL | |     T: Iterator,
+   | |________________^
+   = note: the full type name has been written to '$TEST_BUILD_DIR/recursive-impl-trait-iterator-by-ref-67552.long-type.txt'
+
+error: aborting due to 1 previous error
+