Fix failures of vc-find-revision with non-ASCII file names

* lisp/vc/vc.el (vc-find-revision): Instead of binding
coding-system-for-write, make the buffer-file-coding-system of
the temporary buffer be no-conversion.  This avoids the
unwanted side effect of not encoding the command-line
arguments of the VCS commands invoked by the backend.
(Bug#34350)

1 files changed, 5 insertions, 2 deletions

diff --git a/lisp/vc/vc.el b/lisp/vc/vc.el
index 9925196f737..326284f4446 100644
--- a/lisp/vc/vc.el
+++ b/lisp/vc/vc.el
@@ -1966,10 +1966,13 @@ Use BACKEND as the VC backend if specified."
         (with-current-buffer filebuf
           (let ((failed t))
             (unwind-protect
-                (let ((coding-system-for-read 'no-conversion)
-                      (coding-system-for-write 'no-conversion))
+                (let ((coding-system-for-read 'no-conversion))
                   (with-temp-file filename
                     (let ((outbuf (current-buffer)))
+                      ;; We will read the backend's output with no
+                      ;; conversions, so we should also save the
+                      ;; temporary file with no encoding conversions.
+                      (setq buffer-file-coding-system 'no-conversion)
                       ;; Change buffer to get local value of
                       ;; vc-checkout-switches.
                       (with-current-buffer filebuf