editor: Fix invalid excerpt panic in Editor::hover_links (#40387)

Fixes ZED-17N
Fixes ZED-26Z

Release Notes:

- N/A *or* Added/Fixed/Improved ...

crates/editor/src/editor.rs

@@ -3899,6 +3899,9 @@ impl Editor {
                 }
             })
             .collect::<Vec<_>>();
+        if selection_ranges.is_empty() {
+            return;
+        }
 
         let ranges = match columnar_state {
             ColumnarSelectionState::FromMouse { .. } => {

crates/editor/src/hover_links.rs

@@ -493,22 +493,15 @@ pub fn show_link_definition(
     }
 
     let trigger_anchor = trigger_point.anchor();
-    let Some((buffer, buffer_position)) = editor
-        .buffer
-        .read(cx)
-        .text_anchor_for_position(*trigger_anchor, cx)
-    else {
+    let anchor = snapshot.buffer_snapshot().anchor_before(*trigger_anchor);
+    let Some(buffer) = editor.buffer().read(cx).buffer_for_anchor(anchor, cx) else {
         return;
     };
-
-    let Some((excerpt_id, _, _)) = editor
-        .buffer()
-        .read(cx)
-        .excerpt_containing(*trigger_anchor, cx)
-    else {
-        return;
-    };
-
+    let Anchor {
+        excerpt_id,
+        text_anchor,
+        ..
+    } = anchor;
     let same_kind = hovered_link_state.preferred_kind == preferred_kind
         || hovered_link_state
             .links
@@ -538,7 +531,7 @@ pub fn show_link_definition(
         async move {
             let result = match &trigger_point {
                 TriggerPoint::Text(_) => {
-                    if let Some((url_range, url)) = find_url(&buffer, buffer_position, cx.clone()) {
+                    if let Some((url_range, url)) = find_url(&buffer, text_anchor, cx.clone()) {
                         this.read_with(cx, |_, _| {
                             let range = maybe!({
                                 let start =
@@ -550,7 +543,7 @@ pub fn show_link_definition(
                         })
                         .ok()
                     } else if let Some((filename_range, filename)) =
-                        find_file(&buffer, project.clone(), buffer_position, cx).await
+                        find_file(&buffer, project.clone(), text_anchor, cx).await
                     {
                         let range = maybe!({
                             let start =
@@ -562,7 +555,7 @@ pub fn show_link_definition(
                         Some((range, vec![HoverLink::File(filename)]))
                     } else if let Some(provider) = provider {
                         let task = cx.update(|_, cx| {
-                            provider.definitions(&buffer, buffer_position, preferred_kind, cx)
+                            provider.definitions(&buffer, text_anchor, preferred_kind, cx)
                         })?;
                         if let Some(task) = task {
                             task.await.ok().flatten().map(|definition_result| {