From e44fd920651ae753a71f17c51ce96fce74b2313c Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Mon, 4 Nov 2024 22:08:43 -0500
Subject: [PATCH] Further deconflict macro-generated format var names with
 user-provided ones

---
 impl/src/fmt.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/impl/src/fmt.rs b/impl/src/fmt.rs
index 49e77c5..1c59d10 100644
--- a/impl/src/fmt.rs
+++ b/impl/src/fmt.rs
@@ -78,7 +78,7 @@ impl Display<'_> {
                 }
                 _ => continue,
             };
-            let formatvar = match &member {
+            let mut formatvar = match &member {
                 MemberUnraw::Unnamed(index) => IdentUnraw::new(format_ident!("__field{}", index)),
                 MemberUnraw::Named(ident) => {
                     if user_named_args.contains(ident) || ident == "_" {
@@ -89,6 +89,9 @@ impl Display<'_> {
                     IdentUnraw::new(format_ident!("__field_{}", ident.to_string()))
                 }
             };
+            while user_named_args.contains(&formatvar) {
+                formatvar = IdentUnraw::new(format_ident!("_{}", formatvar.to_string()));
+            }
             out += &formatvar.to_string();
             if !macro_named_args.insert(member.clone()) {
                 // Already added to scope by a previous use.