From 9626f2bd84ccf99635dfdbca3da782db3596190a Mon Sep 17 00:00:00 2001
From: Fabian Wolff <fabian.wolff@alumni.ethz.ch>
Date: Sat, 2 Oct 2021 22:18:11 +0200
Subject: [PATCH] Fix extra `non_snake_case` warning for shorthand field
 bindings

---
 compiler/rustc_lint/src/nonstandard_style.rs | 13 +++++++------
 src/test/ui/lint/issue-89469.rs              | 20 ++++++++++++++++++++
 2 files changed, 27 insertions(+), 6 deletions(-)
 create mode 100644 src/test/ui/lint/issue-89469.rs

diff --git a/compiler/rustc_lint/src/nonstandard_style.rs b/compiler/rustc_lint/src/nonstandard_style.rs
index 03344973bb3e6..bcddc4f3d7643 100644
--- a/compiler/rustc_lint/src/nonstandard_style.rs
+++ b/compiler/rustc_lint/src/nonstandard_style.rs
@@ -437,12 +437,13 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
             if let hir::Node::Pat(parent_pat) = cx.tcx.hir().get(cx.tcx.hir().get_parent_node(hid))
             {
                 if let PatKind::Struct(_, field_pats, _) = &parent_pat.kind {
-                    for field in field_pats.iter() {
-                        if field.ident != ident {
-                            // Only check if a new name has been introduced, to avoid warning
-                            // on both the struct definition and this pattern.
-                            self.check_snake_case(cx, "variable", &ident);
-                        }
+                    if field_pats
+                        .iter()
+                        .any(|field| !field.is_shorthand && field.pat.hir_id == p.hir_id)
+                    {
+                        // Only check if a new name has been introduced, to avoid warning
+                        // on both the struct definition and this pattern.
+                        self.check_snake_case(cx, "variable", &ident);
                     }
                     return;
                 }
diff --git a/src/test/ui/lint/issue-89469.rs b/src/test/ui/lint/issue-89469.rs
new file mode 100644
index 0000000000000..3a6ab452840ac
--- /dev/null
+++ b/src/test/ui/lint/issue-89469.rs
@@ -0,0 +1,20 @@
+// Regression test for #89469, where an extra non_snake_case warning was
+// reported for a shorthand field binding.
+
+// check-pass
+#![deny(non_snake_case)]
+
+#[allow(non_snake_case)]
+struct Entry {
+    A: u16,
+    a: u16
+}
+
+fn foo() -> Entry {todo!()}
+
+pub fn f() {
+    let Entry { A, a } = foo();
+    let _ = (A, a);
+}
+
+fn main() {}