Don't signal error in vc-deduce-backend

* lisp/vc/vc.el (vc-deduce-backend): Return nil if
vc-responsible-backend signals an error.

1 files changed, 3 insertions, 1 deletions

diff --git a/lisp/vc/vc.el b/lisp/vc/vc.el
index 6516c91de3c..e767deace2e 100644
--- a/lisp/vc/vc.el
+++ b/lisp/vc/vc.el
@@ -996,7 +996,9 @@ Within directories, only files already under version control are noticed."
         ((derived-mode-p 'diff-mode)     diff-vc-backend)
         ;; Maybe we could even use comint-mode rather than shell-mode?
         ((derived-mode-p 'dired-mode 'shell-mode 'compilation-mode)
-         (vc-responsible-backend default-directory))
+         (condition-case nil
+             (vc-responsible-backend default-directory)
+           (error nil)))
         (vc-mode (vc-backend buffer-file-name))))
 
 (declare-function vc-dir-current-file "vc-dir" ())