Use the original document and view for mode transition hooks (#3508)

When changing focus, the lookup with `current!` may change the
view and end up executing mode transition hooks on the newly
focused view. We should use the same view and document to execute
mode transition hooks so that switching away from a view triggers
history save points.

helix-term/src/ui/editor.rs

@@ -1157,7 +1157,8 @@ impl Component for EditorView {
                 // clear status
                 cx.editor.status_msg = None;
 
-                let doc = doc!(cx.editor);
+                let (view, doc) = current!(cx.editor);
+                let focus = view.id;
                 let mode = doc.mode();
 
                 if let Some(on_next_key) = self.on_next_key.take() {
@@ -1221,7 +1222,9 @@ impl Component for EditorView {
                     return EventResult::Ignored(None);
                 }
                 let config = cx.editor.config();
-                let (view, doc) = current!(cx.editor);
+                let view = cx.editor.tree.get_mut(focus);
+                let doc = cx.editor.documents.get_mut(&view.doc).unwrap();
+
                 view.ensure_cursor_in_view(doc, config.scrolloff);
 
                 // Store a history state if not in insert mode. This also takes care of