From 8279a9cf4e2ef40b63dfc279e44607e5962ddbeb Mon Sep 17 00:00:00 2001
From: Chris Emerson <github@mail.nosreme.org>
Date: Thu, 7 Nov 2019 21:07:04 +0000
Subject: [PATCH 1/2] Fix some possible panics when using `--check` with stdin.

One case which doesn't work is when there are only line ending fixes;
with stdin rustfmt is unable to detect the difference as it stores
the input with Unix line endings.
---
 src/emitter/diff.rs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/emitter/diff.rs b/src/emitter/diff.rs
index 9be4fb28f99..09b250a13ce 100644
--- a/src/emitter/diff.rs
+++ b/src/emitter/diff.rs
@@ -28,7 +28,7 @@ impl Emitter for DiffEmitter {
 
         if has_diff {
             if self.config.print_misformatted_file_names() {
-                writeln!(output, "{}", ensure_real_path(filename).display())?;
+                writeln!(output, "{}", filename)?;
             } else {
                 print_diff(
                     mismatch,
@@ -40,8 +40,7 @@ impl Emitter for DiffEmitter {
             // This occurs when the only difference between the original and formatted values
             // is the newline style. This happens because The make_diff function compares the
             // original and formatted values line by line, independent of line endings.
-            let file_path = ensure_real_path(filename);
-            writeln!(output, "Incorrect newline style in {}", file_path.display())?;
+            writeln!(output, "Incorrect newline style in {}", filename)?;
             return Ok(EmitterResult { has_diff: true });
         }
 

From bcac2fb524f92959ff700c74e99dbf5ecac05f27 Mon Sep 17 00:00:00 2001
From: Chris Emerson <github@mail.nosreme.org>
Date: Thu, 7 Nov 2019 21:19:24 +0000
Subject: [PATCH 2/2] Add test for `rustfmt --check -l` with stdin.

---
 src/test/mod.rs | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/test/mod.rs b/src/test/mod.rs
index bb92b184be4..fe3378ac1e0 100644
--- a/src/test/mod.rs
+++ b/src/test/mod.rs
@@ -958,3 +958,29 @@ fn verify_check_works_with_stdin() {
         .expect("Failed to wait on rustfmt child");
     assert!(output.status.success());
 }
+
+#[test]
+fn verify_check_l_works_with_stdin() {
+    init_log();
+
+    let mut child = Command::new(rustfmt().to_str().unwrap())
+        .arg("--check")
+        .arg("-l")
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::piped())
+        .spawn()
+        .expect("run with check option failed");
+
+    {
+        let stdin = child.stdin.as_mut().expect("Failed to open stdin");
+        stdin
+            .write_all("fn main()\n{}\n".as_bytes())
+            .expect("Failed to write to rustfmt --check");
+    }
+    let output = child
+        .wait_with_output()
+        .expect("Failed to wait on rustfmt child");
+    assert!(output.status.success());
+    assert_eq!(std::str::from_utf8(&output.stdout).unwrap(), "stdin\n");
+}