ElyMark: R4.10 round 2 fixes (copy guard, component 2b8bd9f)

A pending conversion no longer overwrites a later clipboard write; pin
moves to component 2b8bd9f (one-pass drawn lookup, latest press wins).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

apps/ely-mark/src/blocks/context.rs

@@ -168,12 +168,42 @@ fn copies_convert_off_the_window_thread(cx: &mut TestAppContext) {
     cx.write_to_clipboard(gpui::ClipboardItem::new_string("before".into()));
     // The context's dispatch parks; this one does not.
     cx.update(|window, cx| window.dispatch_action(Box::new(crate::export::CopyHtml), cx));
-    assert_eq!(clipboard(cx).as_deref(), Some("before"), "not on the window thread");
+    assert_eq!(
+        clipboard(cx).as_deref(),
+        Some("before"),
+        "not on the window thread"
+    );
     cx.update(|window, cx| window.dispatch_action(Box::new(crate::export::CopyPlain), cx));
     cx.run_until_parked();
     assert_eq!(clipboard(cx).as_deref(), Some("alpha it\n"));
 }
 
+#[gpui::test]
+fn a_later_markdown_copy_outlives_a_pending_conversion(cx: &mut TestAppContext) {
+    let (_desk, cx, _files) = opened("alpha *it*\n", cx);
+    cx.update(|window, cx| window.dispatch_action(Box::new(crate::export::CopyHtml), cx));
+    cx.update(|window, cx| window.dispatch_action(Box::new(crate::clip::CopyMarkdown), cx));
+    cx.run_until_parked();
+    assert_eq!(clipboard(cx).as_deref(), Some("alpha *it*\n"));
+}
+
+#[gpui::test]
+fn a_later_editor_copy_outlives_a_pending_conversion(cx: &mut TestAppContext) {
+    use gpui::Focusable as _;
+    let (desk, cx, _files) = opened("alpha *it*\n", cx);
+    switch(&desk, Mode::Source, cx);
+    let editor = document(&desk, cx).read_with(cx, |document, _| document.editor().clone());
+    editor.update(cx, |editor, cx| editor.select(std::iter::once(0..5), cx));
+    let focus = editor.read_with(cx, |editor, cx| editor.focus_handle(cx));
+    cx.update(|window, cx| window.focus(&focus, cx));
+    cx.run_until_parked();
+    cx.update(|window, cx| window.dispatch_action(Box::new(crate::export::CopyHtml), cx));
+    let copy = gpui::Keystroke::parse("secondary-c").expect("key");
+    cx.update(|window, cx| window.dispatch_keystroke(copy, cx));
+    cx.run_until_parked();
+    assert_eq!(clipboard(cx).as_deref(), Some("alpha"));
+}
+
 #[gpui::test]
 fn a_shut_menu_stays_shut_when_its_tab_returns(cx: &mut TestAppContext) {
     let (desk, cx, files) = opened("alpha\n", cx);

apps/ely-mark/src/export/copy.rs

@@ -64,6 +64,7 @@ impl Desk {
         let Some((markdown, beside)) = self.copied_text(cx) else {
             return;
         };
+        let before = cx.read_from_clipboard();
         self.copying = Some(cx.spawn(async move |desk, cx| {
             let converted = cx
                 .background_executor()
@@ -71,6 +72,10 @@ impl Desk {
                 .await;
             let landed = desk.update(cx, |desk, cx| {
                 desk.copying = None;
+                // A later copy, here or elsewhere, wins.
+                if cx.read_from_clipboard() != before {
+                    return log::info!("mark: the clipboard changed first; a copy is dropped");
+                }
                 desk.copied(converted, cx);
             });
             if landed.is_err() {