From 57f92698be7b1e2ee880535d7029f10b9e384815 Mon Sep 17 00:00:00 2001
From: Aditya-PS-05 <adityapratapsjnhh7654@gmail.com>
Date: Fri, 28 Nov 2025 15:15:29 +0530
Subject: [PATCH 1/2] add test for borrow checker ICE with nested generic
 closures

---
 tests/ui/issues/issue-143821.rs | 39 +++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 tests/ui/issues/issue-143821.rs

diff --git a/tests/ui/issues/issue-143821.rs b/tests/ui/issues/issue-143821.rs
new file mode 100644
index 0000000000000..f0e308da38718
--- /dev/null
+++ b/tests/ui/issues/issue-143821.rs
@@ -0,0 +1,39 @@
+//@ check-pass
+// Regression test for issue https://github.com/rust-lang/rust/issues/143821
+// Tests that we don't ICE when borrow-checking nested closures with generic type parameters
+// and late-bound lifetime parameters.
+
+fn data_<T: 'static>(_: &()) -> &T {
+    loop {}
+}
+
+fn register<T, F>(f: F) -> IfaceToken<T>
+where
+    T: 'static,
+    F: FnOnce(&()),
+{
+    loop {}
+}
+
+fn method_with_cr_async<CB>(cb: CB)
+where
+    CB: Fn(),
+{
+    loop {}
+}
+
+struct IfaceToken<T: 'static>(T);
+
+fn foo<T>() -> IfaceToken<T> {
+    register::<T, _>(|b: &()| {
+        method_with_cr_async(|| {
+            data_::<T>(&());
+        });
+    })
+}
+
+struct A();
+
+fn main() {
+    foo::<A>();
+}

From 2b4b02e61345e8247064ee35c8a22bf09386685f Mon Sep 17 00:00:00 2001
From: Aditya-PS-05 <adityapratapsjnhh7654@gmail.com>
Date: Fri, 28 Nov 2025 18:52:18 +0530
Subject: [PATCH 2/2] change test location

---
 .../nested-closure-with-generic-ice.rs}                           | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename tests/ui/{issues/issue-143821.rs => borrowck/nested-closure-with-generic-ice.rs} (100%)

diff --git a/tests/ui/issues/issue-143821.rs b/tests/ui/borrowck/nested-closure-with-generic-ice.rs
similarity index 100%
rename from tests/ui/issues/issue-143821.rs
rename to tests/ui/borrowck/nested-closure-with-generic-ice.rs