From b2270e1f459cbeb1b6f4281d230990a40fe993d8 Mon Sep 17 00:00:00 2001
From: Cameron Steffen <cam.steffen94@gmail.com>
Date: Sun, 16 May 2021 17:40:29 -0500
Subject: [PATCH 1/2] Simplify manual_unwrap_or

---
 clippy_lints/src/manual_unwrap_or.rs | 23 ++++-------------------
 1 file changed, 4 insertions(+), 19 deletions(-)

diff --git a/clippy_lints/src/manual_unwrap_or.rs b/clippy_lints/src/manual_unwrap_or.rs
index cf183d4c16f..d7e8d180f7e 100644
--- a/clippy_lints/src/manual_unwrap_or.rs
+++ b/clippy_lints/src/manual_unwrap_or.rs
@@ -54,21 +54,6 @@ impl LateLintPass<'_> for ManualUnwrapOr {
     }
 }
 
-#[derive(Copy, Clone)]
-enum Case {
-    Option,
-    Result,
-}
-
-impl Case {
-    fn unwrap_fn_path(&self) -> &str {
-        match self {
-            Case::Option => "Option::unwrap_or",
-            Case::Result => "Result::unwrap_or",
-        }
-    }
-}
-
 fn lint_manual_unwrap_or<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
     fn applicable_or_arm<'a>(cx: &LateContext<'_>, arms: &'a [Arm<'a>]) -> Option<&'a Arm<'a>> {
         if_chain! {
@@ -101,10 +86,10 @@ fn lint_manual_unwrap_or<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
     if_chain! {
         if let ExprKind::Match(scrutinee, match_arms, _) = expr.kind;
         let ty = cx.typeck_results().expr_ty(scrutinee);
-        if let Some(case) = if is_type_diagnostic_item(cx, ty, sym::option_type) {
-            Some(Case::Option)
+        if let Some(ty_name) = if is_type_diagnostic_item(cx, ty, sym::option_type) {
+            Some("Option")
         } else if is_type_diagnostic_item(cx, ty, sym::result_type) {
-            Some(Case::Result)
+            Some("Result")
         } else {
             None
         };
@@ -127,7 +112,7 @@ fn lint_manual_unwrap_or<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
             span_lint_and_sugg(
                 cx,
                 MANUAL_UNWRAP_OR, expr.span,
-                &format!("this pattern reimplements `{}`", case.unwrap_fn_path()),
+                &format!("this pattern reimplements `{}::unwrap_or`", ty_name),
                 "replace with",
                 format!(
                     "{}.unwrap_or({})",

From 8356c485a99890339022a7afd99fc13ae09e5805 Mon Sep 17 00:00:00 2001
From: Cameron Steffen <cam.steffen94@gmail.com>
Date: Mon, 17 May 2021 14:20:26 -0500
Subject: [PATCH 2/2] Fix manual_unwrap_or FP deref reference

---
 clippy_lints/src/manual_unwrap_or.rs | 4 +---
 tests/ui/manual_unwrap_or.fixed      | 7 +++++++
 tests/ui/manual_unwrap_or.rs         | 7 +++++++
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/clippy_lints/src/manual_unwrap_or.rs b/clippy_lints/src/manual_unwrap_or.rs
index d7e8d180f7e..2f579edd6ad 100644
--- a/clippy_lints/src/manual_unwrap_or.rs
+++ b/clippy_lints/src/manual_unwrap_or.rs
@@ -11,7 +11,6 @@ use rustc_hir::{Arm, Expr, ExprKind, PatKind};
 use rustc_lint::LintContext;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::adjustment::Adjust;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::sym;
 
@@ -72,9 +71,8 @@ fn lint_manual_unwrap_or<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
             if is_lang_ctor(cx, qpath, OptionSome) || is_lang_ctor(cx, qpath, ResultOk);
             if let PatKind::Binding(_, binding_hir_id, ..) = unwrap_pat.kind;
             if path_to_local_id(unwrap_arm.body, binding_hir_id);
+            if cx.typeck_results().expr_adjustments(unwrap_arm.body).is_empty();
             if !contains_return_break_continue_macro(or_arm.body);
-            if !cx.typeck_results().expr_adjustments(unwrap_arm.body).iter()
-                .any(|a| matches!(a.kind, Adjust::Deref(Some(..))));
             then {
                 Some(or_arm)
             } else {
diff --git a/tests/ui/manual_unwrap_or.fixed b/tests/ui/manual_unwrap_or.fixed
index 1efecb0ba12..3717f962745 100644
--- a/tests/ui/manual_unwrap_or.fixed
+++ b/tests/ui/manual_unwrap_or.fixed
@@ -171,4 +171,11 @@ fn format_name(name: Option<&Rc<str>>) -> &str {
     }
 }
 
+fn implicit_deref_ref() {
+    let _: &str = match Some(&"bye") {
+        None => "hi",
+        Some(s) => s,
+    };
+}
+
 fn main() {}
diff --git a/tests/ui/manual_unwrap_or.rs b/tests/ui/manual_unwrap_or.rs
index 95d585ad18a..989adde1f5b 100644
--- a/tests/ui/manual_unwrap_or.rs
+++ b/tests/ui/manual_unwrap_or.rs
@@ -213,4 +213,11 @@ fn format_name(name: Option<&Rc<str>>) -> &str {
     }
 }
 
+fn implicit_deref_ref() {
+    let _: &str = match Some(&"bye") {
+        None => "hi",
+        Some(s) => s,
+    };
+}
+
 fn main() {}