fix "derivable_impls: attributes are ignored"

clippy_lints/src/derivable_impls.rs

@@ -217,8 +217,7 @@ impl<'tcx> LateLintPass<'tcx> for DerivableImpls {
             if let &Adt(adt_def, args) = cx.tcx.type_of(item.owner_id).instantiate_identity().kind();
             if let attrs = cx.tcx.hir().attrs(item.hir_id());
             if !attrs.iter().any(|attr| attr.doc_str().is_some());
-            if let child_attrs = cx.tcx.hir().attrs(impl_item_hir);
-            if !child_attrs.iter().any(|attr| attr.doc_str().is_some());
+            if cx.tcx.hir().attrs(impl_item_hir).is_empty();
 
             then {
                 if adt_def.is_struct() {

tests/ui/derivable_impls.fixed

@@ -287,4 +287,17 @@ mod issue10158 {
     }
 }
 
+mod issue11368 {
+    pub struct A {
+        a: u32,
+    }
+
+    impl Default for A {
+        #[track_caller]
+        fn default() -> Self {
+            Self { a: 0 }
+        }
+    }
+}
+
 fn main() {}

tests/ui/derivable_impls.rs

@@ -323,4 +323,17 @@ mod issue10158 {
     }
 }
 
+mod issue11368 {
+    pub struct A {
+        a: u32,
+    }
+
+    impl Default for A {
+        #[track_caller]
+        fn default() -> Self {
+            Self { a: 0 }
+        }
+    }
+}
+
 fn main() {}