(match-string 2 str)
str)))
+(defun vc-git-symbolic-commit (commit)
+ "Translate COMMIT string into symbolic form.
+Returns nil if not possible."
+ (and commit
+ (with-temp-buffer
+ (and
+ (zerop
+ (call-process "git" nil '(t nil) nil "name-rev"
+ "--name-only" "--tags"
+ commit))
+ (goto-char (point-min))
+ (= (forward-line 2) 1)
+ (bolp)
+ (buffer-substring-no-properties (point-min) (1- (point-max)))))))
+
+(defun vc-git-previous-version (file rev)
+ "git-specific version of `vc-previous-version'."
+ (let ((default-directory (file-name-directory (expand-file-name file)))
+ (file (file-name-nondirectory file)))
+ (vc-git-symbolic-commit
+ (with-temp-buffer
+ (and
+ (zerop
+ (call-process "git" nil '(t nil) nil "rev-list"
+ "-2" rev "--" file))
+ (goto-char (point-max))
+ (bolp)
+ (zerop (forward-line -1))
+ (not (bobp))
+ (buffer-substring-no-properties
+ (point)
+ (1- (point-max))))))))
+
+(defun vc-git-next-version (file rev)
+ "git-specific version of `vc-next-version'."
+ (let* ((default-directory (file-name-directory
+ (expand-file-name file)))
+ (file (file-name-nondirectory file))
+ (current-rev
+ (with-temp-buffer
+ (and
+ (zerop
+ (call-process "git" nil '(t nil) nil "rev-list"
+ "-1" rev "--" file))
+ (goto-char (point-max))
+ (bolp)
+ (zerop (forward-line -1))
+ (bobp)
+ (buffer-substring-no-properties
+ (point)
+ (1- (point-max)))))))
+ (and current-rev
+ (vc-git-symbolic-commit
+ (with-temp-buffer
+ (and
+ (zerop
+ (call-process "git" nil '(t nil) nil "rev-list"
+ "HEAD" "--" file))
+ (goto-char (point-min))
+ (search-forward current-rev nil t)
+ (zerop (forward-line -1))
+ (buffer-substring-no-properties
+ (point)
+ (progn (forward-line 1) (1- (point))))))))))
+
(defun vc-git-revert (file &optional contents-done)
"Revert FILE to the version stored in the git repository."
(if contents-done