From c95fa8cbe22d782cd7bc007dfe06aba9ceddff78 Mon Sep 17 00:00:00 2001
From: Seiichi Uchida <seiichi.uchida@dena.com>
Date: Thu, 7 Jun 2018 12:33:33 +0900
Subject: [PATCH] Return None when the formatting of macro failed in
 format_snippet

---
 src/lib.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/lib.rs b/src/lib.rs
index a8f09e4843d5..8d4cbb51b5a4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -689,6 +689,7 @@ fn format_snippet(snippet: &str, config: &Config) -> Option<String> {
     config.set().hide_parse_errors(true);
     match format_input(input, &config, Some(&mut out)) {
         // `format_input()` returns an empty string on parsing error.
+        Ok((summary, _)) if summary.has_macro_formatting_failure() => None,
         Ok(..) if out.is_empty() && !snippet.is_empty() => None,
         Ok(..) => String::from_utf8(out).ok(),
         Err(..) => None,