From 38b8056fc652ed822c959d45486683147e24f103 Mon Sep 17 00:00:00 2001
From: Mariana Miranda <mariana.almeida.miranda@tecnico.ulisboa.pt>
Date: Thu, 4 Apr 2024 10:24:25 +0100
Subject: [PATCH] Fix: #12268: Correct parentheses for needless_borrow
 suggestion

Clippy no longer adds unnecessary parentheses in suggestion when the expression is a part of a tuple.
---
 clippy_lints/src/dereference.rs | 6 ++++++
 tests/ui/needless_borrow.fixed  | 7 +++++++
 tests/ui/needless_borrow.rs     | 7 +++++++
 tests/ui/needless_borrow.stderr | 8 +++++++-
 4 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs
index 560b2acc1c702..f63413bd575ab 100644
--- a/clippy_lints/src/dereference.rs
+++ b/clippy_lints/src/dereference.rs
@@ -1014,9 +1014,15 @@ fn report<'tcx>(
                         },
                         _ => (0, false),
                     };
+                    let is_in_tuple = match cx.tcx.parent_hir_node(data.first_expr.hir_id) {
+                        Node::Expr(e) => matches!(e.kind, ExprKind::Tup(_)),
+                        _ => false,
+                    };
+
                     let sugg = if !snip_is_macro
                         && (calls_field || expr.precedence().order() < precedence)
                         && !has_enclosing_paren(&snip)
+                        && !is_in_tuple
                     {
                         format!("({snip})")
                     } else {
diff --git a/tests/ui/needless_borrow.fixed b/tests/ui/needless_borrow.fixed
index 998f5430fdf05..adc92be0e1ab3 100644
--- a/tests/ui/needless_borrow.fixed
+++ b/tests/ui/needless_borrow.fixed
@@ -251,3 +251,10 @@ mod issue_10253 {
         (&S).f::<()>();
     }
 }
+
+fn issue_12268() {
+    let option = Some((&1,));
+    let x = (&1,);
+    // Lint here.
+    option.unwrap_or((x.0,));
+}
diff --git a/tests/ui/needless_borrow.rs b/tests/ui/needless_borrow.rs
index acb2c74d849a2..b1f51a2997874 100644
--- a/tests/ui/needless_borrow.rs
+++ b/tests/ui/needless_borrow.rs
@@ -251,3 +251,10 @@ mod issue_10253 {
         (&S).f::<()>();
     }
 }
+
+fn issue_12268() {
+    let option = Some((&1,));
+    let x = (&1,);
+    // Lint here.
+    option.unwrap_or((&x.0,));
+}
diff --git a/tests/ui/needless_borrow.stderr b/tests/ui/needless_borrow.stderr
index 5f02833876422..56fcf1268a17a 100644
--- a/tests/ui/needless_borrow.stderr
+++ b/tests/ui/needless_borrow.stderr
@@ -163,5 +163,11 @@ error: this expression borrows a value the compiler would automatically borrow
 LL |         let _ = &mut (&mut { x.u }).x;
    |                      ^^^^^^^^^^^^^^ help: change this to: `{ x.u }`
 
-error: aborting due to 27 previous errors
+error: this expression creates a reference which is immediately dereferenced by the compiler
+  --> tests/ui/needless_borrow.rs:259:23
+   |
+LL |     option.unwrap_or((&x.0,));
+   |                       ^^^^ help: change this to: `x.0`
+
+error: aborting due to 28 previous errors