Make vc-git-mode-line-string more robust

* lisp/vc/vc-git.el (vc-git-mode-line-string): Make function more
robust (bug#49683).  It could previously error out under certain
conditions, like moving directories in and out of the
VC-controlled tree.

Copyright-paperwork-exempt: yes

diff --git a/lisp/vc/vc-git.el b/lisp/vc/vc-git.el
index 89f9800a1b536436b222379a7b36b4b33cf8f18b..5828a83debcf0babb0b35e774f5b9edc5c2029ef 100644 (file)
--- a/lisp/vc/vc-git.el
+++ b/lisp/vc/vc-git.el
@@ -375,7 +375,7 @@ in the order given by `git status'."
   "Return a string for `vc-mode-line' to put in the mode line for FILE."
   (let* ((rev (vc-working-revision file 'Git))
          (disp-rev (or (vc-git--symbolic-ref file)
-                       (substring rev 0 7)))
+                       (and rev (substring rev 0 7))))
          (def-ml (vc-default-mode-line-string 'Git file))
          (help-echo (get-text-property 0 'help-echo def-ml))
          (face   (get-text-property 0 'face def-ml)))