From 9b45713b6c1775f0103a1ebee6ab7c6d9b781a21 Mon Sep 17 00:00:00 2001
From: Cormac Relf <web@cormacrelf.net>
Date: Wed, 13 Oct 2021 18:08:43 +1100
Subject: [PATCH] let-else: fix attribute aliasing + add test for issue 89807

---
 compiler/rustc_ast_lowering/src/block.rs      |  1 +
 src/test/ui/let-else/let-else-allow-unused.rs | 14 ++++++++++++++
 2 files changed, 15 insertions(+)
 create mode 100644 src/test/ui/let-else/let-else-allow-unused.rs

diff --git a/compiler/rustc_ast_lowering/src/block.rs b/compiler/rustc_ast_lowering/src/block.rs
index 4eab936f85fa0..082c5bb783347 100644
--- a/compiler/rustc_ast_lowering/src/block.rs
+++ b/compiler/rustc_ast_lowering/src/block.rs
@@ -152,6 +152,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             let block = self.lower_block(els, false);
             self.arena.alloc(self.expr_block(block, AttrVec::new()))
         };
+        self.alias_attrs(let_expr.hir_id, local_hir_id);
         self.alias_attrs(else_expr.hir_id, local_hir_id);
         let if_expr = self.arena.alloc(hir::Expr {
             hir_id: stmt_hir_id,
diff --git a/src/test/ui/let-else/let-else-allow-unused.rs b/src/test/ui/let-else/let-else-allow-unused.rs
new file mode 100644
index 0000000000000..bcd8c987628b3
--- /dev/null
+++ b/src/test/ui/let-else/let-else-allow-unused.rs
@@ -0,0 +1,14 @@
+// check-pass
+// issue #89807
+
+#![feature(let_else)]
+
+#[deny(unused_variables)]
+
+fn main() {
+    let value = Some(String::new());
+    #[allow(unused)]
+    let banana = 1;
+    #[allow(unused)]
+    let Some(chaenomeles) = value else { return }; // OK
+}