From a9b0b057eb7c2ff6e764fadc36d94e90e64b5c90 Mon Sep 17 00:00:00 2001
From: Ayaz Hafiz <ayaz.hafiz.1@gmail.com>
Date: Sat, 9 May 2020 16:01:42 -0700
Subject: [PATCH] fixup! Preserve and format type aliases in extern blocks

---
 src/items.rs               | 3 +++
 tests/target/issue-4159.rs | 6 ++++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/items.rs b/src/items.rs
index 2c4570a3a759..4e10d0c47572 100644
--- a/src/items.rs
+++ b/src/items.rs
@@ -1862,6 +1862,9 @@ pub(crate) fn rewrite_type_alias(
         let lhs = format!("{}=", prefix);
         rewrite_assign_rhs(context, lhs, &**ty, shape).map(|s| s + ";")
     } else {
+        if !generics.where_clause.predicates.is_empty() {
+            prefix.push_str(&indent.to_string_with_newline(context.config));
+        }
         Some(format!("{};", prefix))
     }
 }
diff --git a/tests/target/issue-4159.rs b/tests/target/issue-4159.rs
index 52abb132cae8..fed6095354a0 100644
--- a/tests/target/issue-4159.rs
+++ b/tests/target/issue-4159.rs
@@ -3,11 +3,13 @@ extern "C" {
 
     type A<'a>
     where
-        'a: 'static,;
+        'a: 'static,
+    ;
 
     type A<T: Ord>
     where
-        T: 'static,;
+        T: 'static,
+    ;
 
     type A = u8;