master 8761d30: Avoid failing if vc backend doesn't implement ignore-completion-table

[Philip Kaludercic]

branch: master
commit 8761d30da0c4d7d9fd59c192bc283e17b04c5db3
Author: Philip Kaludercic <philipk@posteo.net>
Commit: Philip Kaludercic <philipk@posteo.net>

    Avoid failing if vc backend doesn't implement ignore-completion-table
    
    * project.el (project-ignores): Handle vc-not-supported signals
---
 lisp/progmodes/project.el | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
index ae9bf03..e420a4c 100644
--- a/lisp/progmodes/project.el
+++ b/lisp/progmodes/project.el
@@ -604,7 +604,9 @@ backend implementation of `project-external-roots'.")
                  (replace-match "./" t t entry 1)
                (concat "./" entry)))
             (t entry)))
-         (vc-call-backend backend 'ignore-completion-table root))))
+         (condition-case nil
+             (vc-call-backend backend 'ignore-completion-table root)
+           (vc-not-supported () nil)))))
      (project--value-in-dir 'project-vc-ignores root)
      (mapcar
       (lambda (dir)