Renamed `old_path` to `extra_info` and format it during option parsing

This allows us to use this field for other purposes that aren't
renames.

5 files changed, 29 insertions, 27 deletions

diff --git a/src/display/inline.rs b/src/display/inline.rs
index 3affa674d..d334be040 100644
--- a/src/display/inline.rs
+++ b/src/display/inline.rs
@@ -19,7 +19,7 @@ pub fn print(
     rhs_positions: &[MatchedPos],
     hunks: &[Hunk],
     display_path: &str,
-    old_path: &Option<String>,
+    extra_info: &Option<String>,
     file_format: &FileFormat,
 ) {
     let (lhs_colored_lines, rhs_colored_lines) = if display_options.use_color {
@@ -65,7 +65,7 @@ pub fn print(
             "{}",
             style::header(
                 display_path,
-                old_path,
+                extra_info,
                 i + 1,
                 hunks.len(),
                 file_format,
diff --git a/src/display/style.rs b/src/display/style.rs
index 60c69ed95..efca5dde1 100644
--- a/src/display/style.rs
+++ b/src/display/style.rs
@@ -451,7 +451,7 @@ pub(crate) fn apply_line_number_color(
 
 pub fn header(
     display_path: &str,
-    old_path: &Option<String>,
+    extra_info: &Option<String>,
     hunk_num: usize,
     hunk_total: usize,
     file_format: &FileFormat,
@@ -475,10 +475,9 @@ pub fn header(
         trailer = trailer.dimmed().to_string();
     }
 
-    match old_path {
-        Some(old_path) if hunk_num == 1 => {
-            let renamed = format!("Renamed from {} to {}", old_path, display_path);
-            format!("{}{}\n{}", display_path_pretty, trailer, renamed)
+    match extra_info {
+        Some(extra_info) if hunk_num == 1 => {
+            format!("{}{}\n{}", display_path_pretty, trailer, extra_info)
         }
         _ => {
             format!("{}{}", display_path_pretty, trailer)
diff --git a/src/main.rs b/src/main.rs
index 1a87d4c1f..8eea8b07d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -267,7 +267,7 @@ fn main() {
 /// Print a diff between two files.
 fn diff_file(
     display_path: &str,
-    old_path: Option<String>,
+    extra_info: Option<String>,
     lhs_path: &FileArgument,
     rhs_path: &FileArgument,
     display_options: &DisplayOptions,
@@ -279,7 +279,7 @@ fn diff_file(
     let (lhs_src, rhs_src) = match (guess_content(&lhs_bytes), guess_content(&rhs_bytes)) {
         (ProbableFileKind::Binary, _) | (_, ProbableFileKind::Binary) => {
             return DiffResult {
-                old_path,
+                extra_info,
                 display_path: display_path.to_owned(),
                 file_format: FileFormat::Binary,
                 lhs_src: FileContent::Binary,
@@ -296,7 +296,7 @@ fn diff_file(
 
     diff_file_content(
         display_path,
-        old_path,
+        extra_info,
         lhs_path,
         rhs_path,
         &lhs_src,
@@ -310,7 +310,7 @@ fn diff_file(
 fn check_only_text(
     file_format: &FileFormat,
     display_path: &str,
-    old_path: Option<String>,
+    extra_info: Option<String>,
     lhs_src: &str,
     rhs_src: &str,
 ) -> DiffResult {
@@ -318,7 +318,7 @@ fn check_only_text(
 
     DiffResult {
         display_path: display_path.to_string(),
-        old_path,
+        extra_info,
         file_format: file_format.clone(),
         lhs_src: FileContent::Text(lhs_src.into()),
         rhs_src: FileContent::Text(rhs_src.into()),
@@ -332,7 +332,7 @@ fn check_only_text(
 
 fn diff_file_content(
     display_path: &str,
-    old_path: Option<String>,
+    extra_info: Option<String>,
     _lhs_path: &FileArgument,
     rhs_path: &FileArgument,
     lhs_src: &str,
@@ -359,7 +359,7 @@ fn diff_file_content(
         // If the two files are completely identical, return early
         // rather than doing any more work.
         return DiffResult {
-            old_path,
+            extra_info,
             display_path: display_path.to_string(),
             file_format,
             lhs_src: FileContent::Text("".into()),
@@ -376,7 +376,7 @@ fn diff_file_content(
         None => {
             let file_format = FileFormat::PlainText;
             if diff_options.check_only {
-                return check_only_text(&file_format, display_path, old_path, &lhs_src, &rhs_src);
+                return check_only_text(&file_format, display_path, extra_info, &lhs_src, &rhs_src);
             }
 
             let lhs_positions = line_parser::change_positions(&lhs_src, &rhs_src);
@@ -405,7 +405,7 @@ fn diff_file_content(
 
                                 let has_syntactic_changes = lhs != rhs;
                                 return DiffResult {
-                                    old_path,
+                                    extra_info,
                                     display_path: display_path.to_string(),
                                     file_format,
                                     lhs_src: FileContent::Text(lhs_src.to_owned()),
@@ -498,7 +498,7 @@ fn diff_file_content(
                                 return check_only_text(
                                     &file_format,
                                     display_path,
-                                    old_path,
+                                    extra_info,
                                     &lhs_src,
                                     &rhs_src,
                                 );
@@ -522,7 +522,7 @@ fn diff_file_content(
                         return check_only_text(
                             &file_format,
                             display_path,
-                            old_path,
+                            extra_info,
                             &lhs_src,
                             &rhs_src,
                         );
@@ -551,7 +551,7 @@ fn diff_file_content(
     let has_syntactic_changes = !hunks.is_empty();
 
     DiffResult {
-        old_path,
+        extra_info,
         display_path: display_path.to_string(),
         file_format,
         lhs_src: FileContent::Text(lhs_src.to_owned()),
@@ -616,7 +616,7 @@ fn print_diff_result(display_options: &DisplayOptions, summary: &DiffResult) {
                         "{}",
                         display::style::header(
                             &summary.display_path,
-                            &summary.old_path,
+                            &summary.extra_info,
                             1,
                             1,
                             &summary.file_format,
@@ -643,7 +643,7 @@ fn print_diff_result(display_options: &DisplayOptions, summary: &DiffResult) {
                     "{}",
                     display::style::header(
                         &summary.display_path,
-                        &summary.old_path,
+                        &summary.extra_info,
                         1,
                         1,
                         &summary.file_format,
@@ -672,7 +672,7 @@ fn print_diff_result(display_options: &DisplayOptions, summary: &DiffResult) {
                         &summary.rhs_positions,
                         hunks,
                         &summary.display_path,
-                        &summary.old_path,
+                        &summary.extra_info,
                         &summary.file_format,
                     );
                 }
@@ -681,7 +681,7 @@ fn print_diff_result(display_options: &DisplayOptions, summary: &DiffResult) {
                         hunks,
                         display_options,
                         &summary.display_path,
-                        &summary.old_path,
+                        &summary.extra_info,
                         &summary.file_format,
                         lhs_src,
                         rhs_src,
@@ -697,7 +697,7 @@ fn print_diff_result(display_options: &DisplayOptions, summary: &DiffResult) {
                     "{}",
                     display::style::header(
                         &summary.display_path,
-                        &summary.old_path,
+                        &summary.extra_info,
                         1,
                         1,
                         &FileFormat::Binary,
@@ -718,7 +718,7 @@ fn print_diff_result(display_options: &DisplayOptions, summary: &DiffResult) {
                 "{}",
                 display::style::header(
                     &summary.display_path,
-                    &summary.old_path,
+                    &summary.extra_info,
                     1,
                     1,
                     &FileFormat::Binary,
diff --git a/src/options.rs b/src/options.rs
index 89582bb81..8752f5549 100644
--- a/src/options.rs
+++ b/src/options.rs
@@ -603,12 +603,13 @@ pub fn parse_args() -> Mode {
 
             let old_name = old_name.to_string_lossy().to_string();
             let new_name = new_name.to_string_lossy().to_string();
+            let renamed = format!("Renamed from {} to {}", old_name, new_name);
 
             (
                 new_name,
                 FileArgument::from_path_argument(lhs_tmp_file),
                 FileArgument::from_path_argument(rhs_tmp_file),
-                Some(old_name),
+                Some(renamed),
                 true,
             )
         }
diff --git a/src/summary.rs b/src/summary.rs
index f889d89f9..c5695086a 100644
--- a/src/summary.rs
+++ b/src/summary.rs
@@ -38,7 +38,9 @@ impl Display for FileFormat {
 #[derive(Debug)]
 pub struct DiffResult {
     pub display_path: String,
-    pub old_path: Option<String>,
+    /// Additional information to display about this file, such as
+    /// "Renamed from x.js to y.js".
+    pub extra_info: Option<String>,
 
     pub file_format: FileFormat,
     pub lhs_src: FileContent,