emacs-28 768ed1476a: Make Tramp version check more robust

[Michael Albinus]

branch: emacs-28
commit 768ed1476ae849777457b1eb666a2b0db9eb7374
Author: Michael Albinus <michael.albinus@gmx.de>
Commit: Michael Albinus <michael.albinus@gmx.de>

    Make Tramp version check more robust
    
    * lisp/net/trampver.el (tramp-repository-branch)
    (tramp-repository-version): Check for "git" executable.
---
 lisp/net/trampver.el | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lisp/net/trampver.el b/lisp/net/trampver.el
index 9c04abc828..5863beb295 100644
--- a/lisp/net/trampver.el
+++ b/lisp/net/trampver.el
@@ -58,6 +58,7 @@
       ;; `emacs-repository-get-branch' has been introduced with Emacs 27.1.
       (with-no-warnings
        (and (stringp dir) (file-directory-p dir)
+            (executable-find "git")
             (emacs-repository-get-branch dir)))))
   "The repository branch of the Tramp sources.")
 
@@ -70,6 +71,7 @@
          (dir (or (locate-dominating-file (locate-library "tramp") ".git")
                   source-directory)))
       (and (stringp dir) (file-directory-p dir)
+          (executable-find "git")
           (emacs-repository-get-version dir))))
   "The repository revision of the Tramp sources.")