+;; Set during dumping, this is a defvar so that it can be setq'd.
+(defvar emacs-repository-version nil
+ "String giving the repository revision from which this Emacs was built.
+Value is nil if Emacs was not built from a repository checkout,
+or if we could not determine the revision.")
+
+(define-obsolete-variable-alias 'emacs-bzr-version
+ 'emacs-repository-version "24.4")
+
+(defun emacs-bzr-version-dirstate (dir)
+ "Try to return as a string the bzr revision ID of directory DIR.
+This uses the dirstate file's parent revision entry.
+Returns nil if unable to find this information."
+ (let ((file (expand-file-name ".bzr/checkout/dirstate" dir)))
+ (when (file-readable-p file)
+ (with-temp-buffer
+ (insert-file-contents file)
+ (and (looking-at "#bazaar dirstate flat format 3")
+ (forward-line 3)
+ (looking-at "[0-9]+\0\\([^\0\n]+\\)\0")
+ (match-string 1))))))
+
+(defun emacs-bzr-version-bzr (dir)
+ "Ask bzr itself for the version information for directory DIR."
+ ;; Comments on `bzr version-info':
+ ;; i) Unknown files also cause clean != 1.
+ ;; ii) It can be slow, contacting the upstream repo to get the
+ ;; branch nick if one is not set locally, even with a custom
+ ;; template that is not asking for the nick (as used here). You'd
+ ;; think the latter part would be trivial to fix:
+ ;; https://bugs.launchpad.net/bzr/+bug/882541/comments/3
+ ;; https://bugs.launchpad.net/bzr/+bug/629150
+ ;; You can set the nick locally with `bzr nick ...', which speeds
+ ;; things up enormously. `bzr revno' does not have this issue, but
+ ;; has no way to print the revision_id AFAICS.
+ (message "Waiting for bzr...")
+ (with-temp-buffer
+ (if (zerop
+ (call-process "bzr" nil '(t nil) nil "version-info"
+ "--custom"
+ "--template={revno} {revision_id} (clean = {clean})"
+ dir))
+ (buffer-string))))
+
+(define-obsolete-function-alias 'emacs-bzr-get-version
+ 'emacs-repository-get-version "24.4")
+
+(defun emacs-repository-get-version (&optional dir external)
+ "Try to return as a string the repository revision of the Emacs sources.
+The format of the returned string is dependent on the VCS in use.
+Value is nil if the sources do not seem to be under version
+control, or if we could not determine the revision. Note that
+this reports on the current state of the sources, which may not
+correspond to the running Emacs.
+
+Optional argument DIR is a directory to use instead of
+`source-directory'. Optional argument EXTERNAL non-nil means to
+maybe ask the VCS itself, if the sources appear to be under
+version control. If `force', always ask. the VCS. Otherwise
+only ask the VCS if we cannot find any information ourselves."
+ (or dir (setq dir source-directory))
+ (cond ((file-directory-p (expand-file-name ".bzr/branch" dir))
+ (if (eq external 'force)
+ (emacs-bzr-version-bzr dir)
+ (let (file loc rev)
+ (cond ((file-readable-p
+ (setq file (expand-file-name
+ ".bzr/branch/last-revision" dir)))
+ (with-temp-buffer
+ (insert-file-contents file)
+ (goto-char (point-max))
+ (if (looking-back "\n")
+ (delete-char -1))
+ (buffer-string)))
+ ;; OK, no last-revision. Is it a lightweight checkout?
+ ((file-readable-p
+ (setq file (expand-file-name ".bzr/branch/location" dir)))
+ (setq rev (emacs-bzr-version-dirstate dir))
+ ;; If parent branch is local, try looking there for the rev.
+ ;; Note: there is no guarantee that the parent branch's rev
+ ;; corresponds to this branch. This branch could have
+ ;; been made with a specific -r revno argument, or the
+ ;; parent could have been updated since this branch was
+ ;; created.
+ ;; To try and detect this, we check the dirstate revids
+ ;; to see if they match.
+ (if (and (setq loc (with-temp-buffer
+ (insert-file-contents file)
+ (if (looking-at "file://\\(.*\\)")
+ (match-string 1))))
+ (equal rev (emacs-bzr-version-dirstate loc)))
+ (emacs-repository-get-version loc)
+ ;; If parent does not match, the best we can do without
+ ;; calling external commands is to use the dirstate rev.
+ rev))
+ (external
+ (emacs-bzr-version-bzr dir))))))
+ ((file-directory-p (expand-file-name ".git" dir))
+ (message "Waiting for git...")
+ (with-temp-buffer
+ (let ((default-directory (file-name-as-directory dir)))
+ (and (eq 0
+ (condition-case nil
+ (call-process "git" nil '(t nil) nil "log"
+ "-1" "--pretty=format:%N")
+ (error nil)))
+ (not (zerop (buffer-size)))
+ (replace-regexp-in-string "\n" "" (buffer-string))))))))
+