From 1eff408ca44ae15ffd6592714487f168a5549bcc Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Sun, 30 Apr 2023 13:45:45 +0100
Subject: [PATCH] WIP

---
 clippy_lints/src/trait_bounds.rs            |  5 +++--
 tests/ui/trait_duplication_in_bounds.fixed  | 10 +++++++++
 tests/ui/trait_duplication_in_bounds.rs     |  2 ++
 tests/ui/trait_duplication_in_bounds.stderr | 25 +++++++++++++--------
 4 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/clippy_lints/src/trait_bounds.rs b/clippy_lints/src/trait_bounds.rs
index 13651c978..1af2c5942 100644
--- a/clippy_lints/src/trait_bounds.rs
+++ b/clippy_lints/src/trait_bounds.rs
@@ -195,13 +195,14 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
             let already_seen = !seen_def_ids.insert(def_id);
 
             if already_seen {
-                span_lint_and_help(
+                span_lint_and_sugg(
                     cx,
                     TRAIT_DUPLICATION_IN_BOUNDS,
                     bound.span,
                     "this trait bound is already specified in trait declaration",
-                    None,
                     "consider removing this trait bound",
+                    "".to_string(),
+                    Applicability::MaybeIncorrect,
                 );
             }
         }
diff --git a/tests/ui/trait_duplication_in_bounds.fixed b/tests/ui/trait_duplication_in_bounds.fixed
index eef8024b1..fdac0e4cb 100644
--- a/tests/ui/trait_duplication_in_bounds.fixed
+++ b/tests/ui/trait_duplication_in_bounds.fixed
@@ -2,6 +2,8 @@
 #![deny(clippy::trait_duplication_in_bounds)]
 #![allow(unused)]
 
+use std::any::Any;
+
 fn bad_foo<T: Clone + Copy, U: Clone + Copy>(arg0: T, argo1: U) {
     unimplemented!();
 }
@@ -109,4 +111,12 @@ fn qualified_path<T: std::clone::Clone + foo::Clone>(arg0: T) {
     unimplemented!();
 }
 
+fn good_trait_object(arg0: &(dyn Any + Send)) {
+    unimplemented!();
+}
+
+fn bad_trait_object(arg0: &(dyn Any + Send)) {
+    unimplemented!();
+}
+
 fn main() {}
diff --git a/tests/ui/trait_duplication_in_bounds.rs b/tests/ui/trait_duplication_in_bounds.rs
index f4f4a9fcb..a0300da55 100644
--- a/tests/ui/trait_duplication_in_bounds.rs
+++ b/tests/ui/trait_duplication_in_bounds.rs
@@ -2,6 +2,8 @@
 #![deny(clippy::trait_duplication_in_bounds)]
 #![allow(unused)]
 
+use std::any::Any;
+
 fn bad_foo<T: Clone + Clone + Clone + Copy, U: Clone + Copy>(arg0: T, argo1: U) {
     unimplemented!();
 }
diff --git a/tests/ui/trait_duplication_in_bounds.stderr b/tests/ui/trait_duplication_in_bounds.stderr
index af800ba78..a6508eb86 100644
--- a/tests/ui/trait_duplication_in_bounds.stderr
+++ b/tests/ui/trait_duplication_in_bounds.stderr
@@ -1,5 +1,5 @@
 error: these bounds contain repeated elements
-  --> $DIR/trait_duplication_in_bounds.rs:5:15
+  --> $DIR/trait_duplication_in_bounds.rs:7:15
    |
 LL | fn bad_foo<T: Clone + Clone + Clone + Copy, U: Clone + Copy>(arg0: T, argo1: U) {
    |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone + Copy`
@@ -11,46 +11,53 @@ LL | #![deny(clippy::trait_duplication_in_bounds)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: these where clauses contain repeated elements
-  --> $DIR/trait_duplication_in_bounds.rs:11:8
+  --> $DIR/trait_duplication_in_bounds.rs:13:8
    |
 LL |     T: Clone + Clone + Clone + Copy,
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone + Copy`
 
 error: these bounds contain repeated elements
-  --> $DIR/trait_duplication_in_bounds.rs:39:26
+  --> $DIR/trait_duplication_in_bounds.rs:41:26
    |
 LL | trait BadSelfTraitBound: Clone + Clone + Clone {
    |                          ^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone`
 
 error: these where clauses contain repeated elements
-  --> $DIR/trait_duplication_in_bounds.rs:46:15
+  --> $DIR/trait_duplication_in_bounds.rs:48:15
    |
 LL |         Self: Clone + Clone + Clone;
    |               ^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone`
 
 error: these bounds contain repeated elements
-  --> $DIR/trait_duplication_in_bounds.rs:60:24
+  --> $DIR/trait_duplication_in_bounds.rs:62:24
    |
 LL | trait BadTraitBound<T: Clone + Clone + Clone + Copy, U: Clone + Copy> {
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone + Copy`
 
 error: these where clauses contain repeated elements
-  --> $DIR/trait_duplication_in_bounds.rs:67:12
+  --> $DIR/trait_duplication_in_bounds.rs:69:12
    |
 LL |         T: Clone + Clone + Clone + Copy,
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Clone + Copy`
 
 error: these bounds contain repeated elements
-  --> $DIR/trait_duplication_in_bounds.rs:100:19
+  --> $DIR/trait_duplication_in_bounds.rs:102:19
    |
 LL | fn bad_generic<T: GenericTrait<u64> + GenericTrait<u32> + GenericTrait<u64>>(arg0: T) {
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `GenericTrait<u64> + GenericTrait<u32>`
 
 error: these bounds contain repeated elements
-  --> $DIR/trait_duplication_in_bounds.rs:108:22
+  --> $DIR/trait_duplication_in_bounds.rs:110:22
    |
 LL | fn qualified_path<T: std::clone::Clone + Clone + foo::Clone>(arg0: T) {
    |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::clone::Clone + foo::Clone`
 
-error: aborting due to 8 previous errors
+error: this trait bound is already specified in trait declaration
+  --> $DIR/trait_duplication_in_bounds.rs:118:46
+   |
+LL | fn bad_trait_object(arg0: &(dyn Any + Send + Send)) {
+   |                                              ^^^^ help: consider removing this trait bound
+   |
+
+error: aborting due to 9 previous errors