Make Info completion more robust

* lisp/info.el (Info-build-node-completions): Don't signal an
error if there are no nodes in the file we're computing
completions over (bug#47771).

1 files changed, 11 insertions, 4 deletions

diff --git a/lisp/info.el b/lisp/info.el
index 67d27c78988..2757ed57826 100644
--- a/lisp/info.el
+++ b/lisp/info.el
@@ -1882,10 +1882,17 @@ the Top node in FILENAME."
       (or (cdr (assoc filename Info-file-completions))
           (with-temp-buffer
             (Info-mode)
-            (Info-goto-node (format "(%s)Top" filename))
-            (Info-build-node-completions-1)
-            (push (cons filename Info-current-file-completions) Info-file-completions)
-            Info-current-file-completions))
+            (condition-case nil
+                (Info-goto-node (format "(%s)Top" filename))
+              ;; `Info-goto-node' signals a `user-error' when there
+              ;; are no nodes in the file in question (for instance,
+              ;; if it's not actually an Info file).
+              (user-error nil)
+              (:success
+               (Info-build-node-completions-1)
+               (push (cons filename Info-current-file-completions)
+                     Info-file-completions)
+               Info-current-file-completions))))
     (or Info-current-file-completions
         (Info-build-node-completions-1))))