Match original line endings in format output on Windows

On Windows, bsc writes CRLF to stdout in text mode. When the original
source file uses LF line endings, the formatted output would introduce
unwanted CRLF conversions. Detect the original file's line ending style
and normalize the formatted output to match.

Author: nojaf

rewatch/src/format.rs

@@ -98,7 +98,25 @@ fn format_files(bsc_exe: &Path, files: Vec<String>, check: bool) -> Result<()> {
 
             if output.status.success() {
                 let original_content = fs::read_to_string(file)?;
-                let formatted_content = String::from_utf8_lossy(&output.stdout);
+                let formatted_content = {
+                    let raw = String::from_utf8_lossy(&output.stdout);
+                    // On Windows, bsc writes CRLF to stdout (text mode).
+                    // Match the line ending style of the original file so we
+                    // don't introduce unwanted conversions.
+                    #[cfg(windows)]
+                    {
+                        let original_has_crlf = original_content.contains("\r\n");
+                        if !original_has_crlf && raw.contains("\r\n") {
+                            std::borrow::Cow::Owned(raw.replace("\r\n", "\n"))
+                        } else {
+                            raw
+                        }
+                    }
+                    #[cfg(not(windows))]
+                    {
+                        raw
+                    }
+                };
                 if original_content != formatted_content {
                     if check {
                         eprintln!("[format check] {file}");