Fix ICE in utils::implements_trait

This only happend when debug_assertions were enabled in rustc

2 files changed, 8 insertions, 0 deletions

diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs
index 5bd64dcb541..e9c71e23a67 100644
--- a/clippy_lints/src/utils/mod.rs
+++ b/clippy_lints/src/utils/mod.rs
@@ -365,6 +365,9 @@ pub fn implements_trait<'tcx>(
         return false;
     }
     let ty = cx.tcx.erase_regions(ty);
+    if ty.has_escaping_bound_vars() {
+        return false;
+    }
     let ty_params = cx.tcx.mk_substs(ty_params.iter());
     cx.tcx.type_implements_trait((trait_id, ty, ty_params, cx.param_env))
 }
diff --git a/tests/ui/crashes/implements-trait.rs b/tests/ui/crashes/implements-trait.rs
new file mode 100644
index 00000000000..4502b0147a8
--- /dev/null
+++ b/tests/ui/crashes/implements-trait.rs
@@ -0,0 +1,5 @@
+#[allow(clippy::needless_borrowed_reference)]
+fn main() {
+    let mut v = Vec::<String>::new();
+    let _ = v.iter_mut().filter(|&ref a| a.is_empty());
+}