Simplify preparation of hunk header code fragment

src/delta.rs

@@ -442,7 +442,7 @@ fn handle_hunk_line(
             };
             painter
                 .minus_lines
-                .push((painter.prepare(&line, true), state.clone()));
+                .push((painter.prepare(&line), state.clone()));
             state
         }
         Some('+') => {
@@ -459,7 +459,7 @@ fn handle_hunk_line(
             };
             painter
                 .plus_lines
-                .push((painter.prepare(&line, true), state.clone()));
+                .push((painter.prepare(&line), state.clone()));
             state
         }
         Some(' ') => {

src/hunk_header.rs

@@ -75,16 +75,12 @@ fn _write_hunk_header(
     config: &Config,
 ) -> std::io::Result<()> {
     let (mut draw_fn, _, decoration_ansi_term_style) = _get_draw_fn(config);
-    // Adjust the hunk-header-line before paint_lines.
-    // However in the case of color_only mode,
-    // we'll just use raw_line because we can't change raw_line structure.
     let line = if config.color_only {
         format!(" {}", &line)
+    } else if !raw_code_fragment.is_empty() {
+        format!("{} ", raw_code_fragment)
     } else {
-        match painter.prepare(&raw_code_fragment, false) {
-            s if !s.is_empty() => format!("{} ", s),
-            s => s,
-        }
+        "".to_string()
     };
 
     // Add a blank line below the hunk-header-line for readability, unless

src/paint.rs

@@ -78,8 +78,7 @@ impl<'a> Painter<'a> {
     // Terminating with newline character is necessary for many of the sublime syntax definitions to
     // highlight correctly.
     // See https://docs.rs/syntect/3.2.0/syntect/parsing/struct.SyntaxSetBuilder.html#method.add_from_folder
-    pub fn prepare(&self, line: &str, append_newline: bool) -> String {
-        let terminator = if append_newline { "\n" } else { "" };
+    pub fn prepare(&self, line: &str) -> String {
         if !line.is_empty() {
             let mut line = line.graphemes(true);
 
@@ -90,9 +89,9 @@ impl<'a> Painter<'a> {
             // TODO: Things should, but do not, work if this leading space is omitted at this stage.
             // See comment in align::Alignment::new.
             line.next();
-            format!(" {}{}", self.expand_tabs(line), terminator)
+            format!(" {}\n", self.expand_tabs(line))
         } else {
-            terminator.to_string()
+            "\n".to_string()
         }
     }
 
@@ -201,7 +200,7 @@ impl<'a> Painter<'a> {
         } else {
             None
         };
-        let lines = vec![(self.prepare(line, true), state.clone())];
+        let lines = vec![(self.prepare(line), state.clone())];
         let syntax_style_sections = Painter::get_syntax_style_sections_for_lines(
             &lines,
             &state,