Fix special ASCII characters not being escaped when copied to clipboard (#306)

objdiff-gui/src/views/diff.rs

@@ -865,6 +865,24 @@ pub fn hover_items_ui(ui: &mut Ui, items: Vec<HoverItem>, appearance: &Appearanc
     }
 }
 
+/// Escape ASCII characters such as \n or \t, but not Unicode characters such as \u{3000}.
+/// Suitable for copying to clipboard.
+fn escape_special_ascii_characters(value: String) -> String {
+    let mut escaped = String::new();
+    escaped.push('"');
+    for c in value.chars() {
+        if c.is_ascii() {
+            for e in c.escape_default() {
+                escaped.push(e);
+            }
+        } else {
+            escaped.push(c);
+        }
+    }
+    escaped.push('"');
+    escaped
+}
+
 pub fn context_menu_items_ui(
     ui: &mut Ui,
     items: Vec<ContextItem>,
@@ -894,7 +912,8 @@ pub fn context_menu_items_ui(
                     write_text(")", appearance.text_color, &mut job, appearance.code_font.clone());
                 }
                 if ui.button(job).clicked() {
-                    ui.ctx().copy_text(value);
+                    let escaped = escape_special_ascii_characters(value);
+                    ui.ctx().copy_text(escaped);
                     ui.close();
                 }
             }