Only give autofix suggestion when no named args are present

2 files changed, 8 insertions, 2 deletions

diff --git a/compiler/rustc_builtin_macros/src/errors.rs b/compiler/rustc_builtin_macros/src/errors.rs
index 7a8ec5cfdf3..fde4270334b 100644
--- a/compiler/rustc_builtin_macros/src/errors.rs
+++ b/compiler/rustc_builtin_macros/src/errors.rs
@@ -657,7 +657,7 @@ pub(crate) struct FormatRedundantArgs {
     pub(crate) note: MultiSpan,
 
     #[subdiagnostic]
-    pub(crate) sugg: FormatRedundantArgsSugg,
+    pub(crate) sugg: Option<FormatRedundantArgsSugg>,
 }
 
 #[derive(Subdiagnostic)]
diff --git a/compiler/rustc_builtin_macros/src/format.rs b/compiler/rustc_builtin_macros/src/format.rs
index e08fded01fb..7c78be17653 100644
--- a/compiler/rustc_builtin_macros/src/format.rs
+++ b/compiler/rustc_builtin_macros/src/format.rs
@@ -767,11 +767,17 @@ fn report_redundant_format_arguments<'a>(
             suggestion_spans.push(span);
         }
 
+        let sugg = if args.named_args().len() == 0 {
+            Some(errors::FormatRedundantArgsSugg { spans: suggestion_spans })
+        } else {
+            None
+        };
+
         return Some(ecx.create_err(errors::FormatRedundantArgs {
             n: args_spans.len(),
             span: MultiSpan::from(args_spans),
             note: multispan,
-            sugg: errors::FormatRedundantArgsSugg { spans: suggestion_spans },
+            sugg,
         }));
     }