master 4470996198d: * lisp/vc/vc-hg.el (vc-hg-previous-revision): Use 'hg log'.

branch: master
commit 4470996198d1cad003c174aee478c65cb439a7af
Author: Sean Whitton <[email protected]>
Commit: Sean Whitton <[email protected]>

    * lisp/vc/vc-hg.el (vc-hg-previous-revision): Use 'hg log'.
    
    'hg id' is much slower than 'hg log'.
---
 lisp/vc/vc-hg.el | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/lisp/vc/vc-hg.el b/lisp/vc/vc-hg.el
index 7a073d0b20b..0fa22d97fad 100644
--- a/lisp/vc/vc-hg.el
+++ b/lisp/vc/vc-hg.el
@@ -1158,11 +1158,11 @@ hg binary."
         (t
          ;; We can't simply decrement by 1, because that revision might
          ;; be e.g. on a different branch (bug#22032).
-         (with-temp-buffer
-           (and (zerop (vc-hg-command t nil nil "id" "-n"
-                                      "-r" (concat rev "~1")))
-                ;; Trim the trailing newline.
-                (buffer-substring (point-min) (1- (point-max))))))))
+         (with-output-to-string
+           (vc-hg-command standard-output 0 nil "log"
+                          "-r" (format "revset(%s~1)" rev)
+                          "--template" (if vc-use-short-revision
+                                           "{node|short}" "{node}"))))))
 
 (defun vc-hg-next-revision (_file rev)
   (let ((newrev (1+ (string-to-number rev)))