typography and documents: an exported formula frames its outlined text; rendered modes have no source selection

src/documents/document/place.rs

@@ -31,6 +31,10 @@ impl MarkdownDocument {
     /// The selected Markdown: the source's, or the open block's.
     pub fn selected(&self, cx: &App) -> String {
         let Some(open) = &self.open else {
+            // Rendered modes show no source selection.
+            if !matches!(self.mode, MarkdownMode::Source | MarkdownMode::Split) {
+                return String::new();
+            }
             let editor = self.editor.read(cx);
             return editor.text()[editor.primary().range()].to_string();
         };

src/documents/document/tests/place.rs

@@ -211,10 +211,14 @@ fn the_selection_reads_in_source_and_in_an_open_block(cx: &mut TestAppContext) {
         document.read_with(cx, |document, cx| document.selected(cx)),
         "One"
     );
-    document.update_in(cx, |document, window, cx| {
-        document.set_mode(MarkdownMode::Visual, window, cx)
-    });
-    frames(cx);
+    for mode in [MarkdownMode::Preview, MarkdownMode::Visual] {
+        document.update_in(cx, |document, window, cx| {
+            document.set_mode(mode, window, cx)
+        });
+        frames(cx);
+        let selected = document.read_with(cx, |document, cx| document.selected(cx));
+        assert_eq!(selected, "", "{mode:?} shows no source selection");
+    }
     super::type_in(&document, Some(1), None, cx);
     document.update(cx, |document, cx| {
         let open = document.open.as_ref().expect("a block is open");