Avoid adding unnecessary spans when syntax highlighting

Cargo.toml

@@ -154,7 +154,7 @@ winit = { git = "https://github.com/iced-rs/winit.git", rev = "c52db2045d0a2f1b8
 
 [patch.crates-io.cosmic-text]
 git = "https://github.com/hecrj/cosmic-text.git"
-rev = "cb83458e7d0b84ef37c5beb72dda5046d7d343a6"
+branch = "editor-fixes"
 
 [patch.crates-io.rangemap]
 git = "https://github.com/hecrj/rangemap.git"

graphics/src/text/editor.rs

@@ -569,17 +569,19 @@ impl editor::Editor for Editor {
             for (range, highlight) in highlighter.highlight_line(line.text()) {
                 let format = format_highlight(&highlight);
 
-                list.add_span(
-                    range,
-                    cosmic_text::Attrs {
-                        color_opt: format.color.map(text::to_color),
-                        ..if let Some(font) = format.font {
-                            text::to_attributes(font)
-                        } else {
-                            attributes
-                        }
-                    },
-                );
+                if format.color.is_some() || format.font.is_some() {
+                    list.add_span(
+                        range,
+                        cosmic_text::Attrs {
+                            color_opt: format.color.map(text::to_color),
+                            ..if let Some(font) = format.font {
+                                text::to_attributes(font)
+                            } else {
+                                attributes
+                            }
+                        },
+                    );
+                }
             }
 
             let _ = line.set_attrs_list(list);