bug#27840: 26.0.50; vc-git-grep stopped working on git master

[Dmitry Gutov <dgutov@yandex.ru>]

On 7/27/17 2:32 AM, npostavs@users.sourceforge.net wrote:

> Perhaps we should
> instead disable this option by default; when I introduced it, I didn't
> think about the fact that grep.el is used for not-quite-grep programs as
> well.

Or we can try to think of them as separate. I.e., the patch below also 
works. And if we want to use the --null option for vc-git-grep, we can 
construct a derivative alist in vc-git.el.

Up to you, of course.

diff --git a/lisp/vc/vc-git.el b/lisp/vc/vc-git.el
index cc3e295..f52dc6e 100644
--- a/lisp/vc/vc-git.el
+++ b/lisp/vc/vc-git.el
@@ -1443,7 +1443,8 @@ vc-git-grep
  	    (add-to-history 'grep-history command))))
        (when command
  	(let ((default-directory dir)
-	      (compilation-environment (cons "PAGER=" compilation-environment)))
+	      (compilation-environment (cons "PAGER=" compilation-environment))
+              grep-use-null-filename-separator)
  	  ;; Setting process-setup-function makes exit-message-function work
  	  ;; even when async processes aren't supported.
  	  (compilation-start command 'grep-mode))