Handle deleted parser in treesit-explore-mode (bug#76398)

(Unrelated to the topic of the bug, but mentioned in the
thread.)

* lisp/treesit.el (treesit--explorer-refresh-1): New function.
(treesit--explorer-refresh): Handle 'treesit-parser-deleted'
error.

1 files changed, 14 insertions, 1 deletions

diff --git a/lisp/treesit.el b/lisp/treesit.el
index 36f26ea5825..2d8eebbbff5 100644
--- a/lisp/treesit.el
+++ b/lisp/treesit.el
@@ -4525,7 +4525,7 @@ in the region."
                (<= (treesit-node-end n) end))
              t t)))))
 
-(defun treesit--explorer-refresh ()
+(defun treesit--explorer-refresh-1 ()
   "Update the syntax tree buffer."
   (when (and treesit-explore-mode
              (buffer-live-p treesit--explorer-buffer))
@@ -4576,6 +4576,19 @@ in the region."
                 (set-window-start window (point))))
             (set-window-point window pos)))))))
 
+(defun treesit--explorer-refresh ()
+  "Update the syntax tree buffer."
+  (condition-case nil
+      (treesit--explorer-refresh-1)
+    (treesit-parser-deleted
+     (when treesit--explorer-buffer
+       (with-current-buffer treesit--explorer-buffer
+         (let ((inhibit-read-only t))
+           (goto-char (point-min))
+           (unless (looking-at "Parser is deleted")
+             (insert (propertize "Parser is deleted\n"
+                                 'face 'error)))))))))
+
 (defun treesit--explorer-post-command (&rest _)
   "Post-command function that runs in the source buffer."
   (when treesit-explore-mode