From ede96cdb1b219c775eade1c0d3559693811e72df Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Sun, 10 Dec 2023 17:59:49 -0800
Subject: [PATCH 1/2] Add test reproducing unary None-delimited group
 precedence bug

---
 tests/test_expr.rs | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/tests/test_expr.rs b/tests/test_expr.rs
index 9d0b44f9ba..ca5d270f3c 100644
--- a/tests/test_expr.rs
+++ b/tests/test_expr.rs
@@ -216,6 +216,30 @@ fn test_macro_variable_struct() {
     "###);
 }
 
+#[test]
+fn test_macro_variable_unary() {
+    // mimics the token stream corresponding to `$expr.method()` where expr is `&self`
+    let inner = Group::new(Delimiter::None, quote!(&self));
+    let tokens = quote!(#inner.method());
+    // FIXME
+    snapshot!(tokens as Expr, @r###"
+    Expr::Reference {
+        expr: Expr::MethodCall {
+            receiver: Expr::Path {
+                path: Path {
+                    segments: [
+                        PathSegment {
+                            ident: "self",
+                        },
+                    ],
+                },
+            },
+            method: "method",
+        },
+    }
+    "###);
+}
+
 #[test]
 fn test_macro_variable_match_arm() {
     // mimics the token stream corresponding to `match v { _ => $expr }`

From 1ffbda912e6abb80a39775a1821579731f992c50 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Sun, 10 Dec 2023 18:00:51 -0800
Subject: [PATCH 2/2] Respect None-delimited group when parsing unary expr

---
 src/expr.rs        |  4 ++++
 tests/test_expr.rs | 23 ++++++++++++-----------
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/src/expr.rs b/src/expr.rs
index f3e37d49c7..334caada90 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -1368,6 +1368,10 @@ pub(crate) mod parsing {
     fn unary_expr(input: ParseStream, allow_struct: AllowStruct) -> Result<Expr> {
         let begin = input.fork();
         let attrs = input.call(expr_attrs)?;
+        if input.peek(token::Group) {
+            return trailer_expr(begin, attrs, input, allow_struct);
+        }
+
         if input.peek(Token![&]) {
             let and_token: Token![&] = input.parse()?;
             let raw: Option<kw::raw> = if input.peek(kw::raw)
diff --git a/tests/test_expr.rs b/tests/test_expr.rs
index ca5d270f3c..64cbea88f7 100644
--- a/tests/test_expr.rs
+++ b/tests/test_expr.rs
@@ -221,21 +221,22 @@ fn test_macro_variable_unary() {
     // mimics the token stream corresponding to `$expr.method()` where expr is `&self`
     let inner = Group::new(Delimiter::None, quote!(&self));
     let tokens = quote!(#inner.method());
-    // FIXME
     snapshot!(tokens as Expr, @r###"
-    Expr::Reference {
-        expr: Expr::MethodCall {
-            receiver: Expr::Path {
-                path: Path {
-                    segments: [
-                        PathSegment {
-                            ident: "self",
-                        },
-                    ],
+    Expr::MethodCall {
+        receiver: Expr::Group {
+            expr: Expr::Reference {
+                expr: Expr::Path {
+                    path: Path {
+                        segments: [
+                            PathSegment {
+                                ident: "self",
+                            },
+                        ],
+                    },
                 },
             },
-            method: "method",
         },
+        method: "method",
     }
     "###);
 }