From 00a20bceff40e98034a7346e5cc6319cbd2d21b7 Mon Sep 17 00:00:00 2001
From: Ivan Komarov <Ivan.Komarov@dfyz.info>
Date: Sat, 27 Oct 2018 04:01:37 +0300
Subject: [PATCH] Fix formatting failures on Windows

When newline_style is set to Windows, an empty line inside of a macro
results in `\r` being passed to the `fold()` in `MacroBranch::rewrite()`.

`\r` is technically not an empty string, so we try to indent it, leaving
trailing whitespaces behind, even though that was not intended
(as far as I can see).

This commit replaces the `!l.is_empty()` check with calling
`is_empty_line()`, since trying to indent any whitespace-only string
will probably result in problematic trailing whitespaces.

Fixes: #2810
---
 src/macros.rs              |  2 +-
 tests/target/issue-2810.rs | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 tests/target/issue-2810.rs

diff --git a/src/macros.rs b/src/macros.rs
index d378bb8ffb14..43f3071b70a6 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -1347,7 +1347,7 @@ impl MacroBranch {
             .fold(
                 (String::new(), true),
                 |(mut s, need_indent), (i, (kind, ref l))| {
-                    if !l.is_empty()
+                    if !is_empty_line(l)
                         && need_indent
                         && !new_body_snippet.is_line_non_formatted(i + 1)
                     {
diff --git a/tests/target/issue-2810.rs b/tests/target/issue-2810.rs
new file mode 100644
index 000000000000..34140c7a1fc6
--- /dev/null
+++ b/tests/target/issue-2810.rs
@@ -0,0 +1,14 @@
+// rustfmt-newline_style: Windows
+
+#[macro_export]
+macro_rules! hmmm___ffi_error {
+    ($result:ident) => {
+        pub struct $result {
+            success: bool,
+        }
+
+        impl $result {
+            pub fn foo(self) {}
+        }
+    };
+}