Tweaks for getting repository version; a bit more like it was for bzr.

* lisp/version.el (emacs-repository-version-git)
(emacs-repository--version-git-1): New functions,
split from emacs-repository-get-version.
(emacs-repository-get-version): Make the second argument meaningful.

1 files changed, 41 insertions, 28 deletions

diff --git a/lisp/version.el b/lisp/version.el
index 5776e6d7b26..112611d1083 100644
--- a/lisp/version.el
+++ b/lisp/version.el
@@ -100,7 +100,30 @@ or if we could not determine the revision.")
 (define-obsolete-function-alias 'emacs-bzr-get-version
                                 'emacs-repository-get-version "24.4")
 
-(defun emacs-repository-get-version (&optional dir _unused)
+(defun emacs-repository-version-git (dir)
+  "Ask git itself for the version information for directory DIR."
+  (message "Waiting for git...")
+  (with-temp-buffer
+    (let ((default-directory (file-name-as-directory dir)))
+      (and (eq 0
+               (ignore-errors
+                 (call-process "git" nil '(t nil) nil "rev-parse" "HEAD")))
+           (not (zerop (buffer-size)))
+           (replace-regexp-in-string "\n" "" (buffer-string))))))
+
+(defun emacs-repository--version-git-1 (file)
+  "Internal subroutine of `emacs-repository-get-version'."
+  (when (file-readable-p file)
+    (erase-buffer)
+    (insert-file-contents file)
+    (cond ((looking-at "[0-9a-fA-F]\\{40\\}")
+           (match-string 0))
+          ((looking-at "ref: \\(.*\\)")
+           (emacs-repository--version-git-1
+            (expand-file-name (match-string 1)
+                              (file-name-directory file)))))))
+
+(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
@@ -108,35 +131,25 @@ 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 DIR is a directory to use instead of `source-directory'.
+Optional argument EXTERNAL non-nil means to just ask the VCS itself,
+if the sources appear to be under version control.  Otherwise only ask
+the VCS if we cannot find any information ourselves."
   (or dir (setq dir source-directory))
-  (let ((file (expand-file-name ".git/HEAD" dir)))
-    (or (if (file-readable-p file)
+  (when (file-directory-p (expand-file-name ".git" dir))
+    (if external
+        (emacs-repository-version-git dir)
+      (or (let ((files '("HEAD" "refs/heads/master"))
+                file rev)
             (with-temp-buffer
-              (insert-file-contents file)
-              (cond ((looking-at "[0-9a-fA-F]\\{40\\}")
-                     (match-string 0))
-                    ((looking-at "ref: \\(.*\\)")
-                     (when (file-readable-p
-                            (setq file
-                                  (expand-file-name (format ".git/%s"
-                                                            (match-string 1))
-                                                    dir)))
-                       (erase-buffer)
-                       (insert-file-contents file)
-                       (if (looking-at "[0-9a-fA-F]\\{40\\}")
-                           (match-string 0)))))))
-        (when (file-accessible-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 "rev-parse"
-                                         "HEAD")
-                         (error nil)))
-                   (not (zerop (buffer-size)))
-                   (replace-regexp-in-string "\n" "" (buffer-string)))))))))
+              (while (and (not rev)
+                          (setq file (car files)))
+                (setq file (expand-file-name (format ".git/%s" file) dir)
+                      files (cdr files)
+                      rev (emacs-repository--version-git-1 file))))
+            rev)
+          ;; AFAICS this doesn't work during dumping (bug#20799).
+          (emacs-repository-version-git dir)))))
 
 ;; We put version info into the executable in the form that `ident' uses.
 (purecopy (concat "\n$Id: " (subst-char-in-string ?\n ?\s (emacs-version))