From f6cd75fb1bb20d75fff2dba560a124fa1b10f1cd Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Sat, 6 Jul 2024 19:59:41 -0700
Subject: [PATCH] Parenthesize leading Expr::Let in statement

---
 src/fixup.rs       | 1 +
 tests/test_expr.rs | 1 +
 2 files changed, 2 insertions(+)

diff --git a/src/fixup.rs b/src/fixup.rs
index 9423e36954..ddee906fb5 100644
--- a/src/fixup.rs
+++ b/src/fixup.rs
@@ -221,6 +221,7 @@ impl FixupContext {
     /// examples.
     pub fn would_cause_statement_boundary(self, expr: &Expr) -> bool {
         (self.leftmost_subexpression_in_stmt && !classify::requires_semi_to_be_stmt(expr))
+            || ((self.stmt || self.leftmost_subexpression_in_stmt) && matches!(expr, Expr::Let(_)))
             || (self.leftmost_subexpression_in_match_arm
                 && !classify::requires_comma_to_be_match_arm(expr))
     }
diff --git a/tests/test_expr.rs b/tests/test_expr.rs
index 3849286431..11d0f86c50 100644
--- a/tests/test_expr.rs
+++ b/tests/test_expr.rs
@@ -680,6 +680,7 @@ fn test_fixup() {
         quote! { (..) = () },
         quote! { (..) += () },
         quote! { (1 < 2) == (3 < 4) },
+        quote! { { (let _ = ()) } },
     ] {
         let original: Expr = syn::parse2(tokens).unwrap();