Emacs mode: automatically cd up to root of worktree

git's emacs mode automatically finds the root of the worktree, so that
the user doesn't have to. Teach StGit's emacs mode the same trick by
borrowing the git-get-top-dir function from git.

The borrowed code was written by Alexandre Julliard <julliard@winehq.org>.

Signed-off-by: Karl Hasselström <kha@treskal.com>

diff --git a/contrib/stgit.el b/contrib/stgit.el
index 339ef13eb950de0cffc0e734cfea7ddaee514a28..2a6fee3becf56aaf598faab77a12e41f67f279b6 100644 (file)
--- a/contrib/stgit.el
+++ b/contrib/stgit.el
@@ -12,9 +12,20 @@
 (defun stgit (dir)
   "Manage stgit patches"
   (interactive "DDirectory: \n")
-  (switch-to-stgit-buffer dir)
+  (switch-to-stgit-buffer (git-get-top-dir dir))
   (stgit-refresh))
 
+(defun git-get-top-dir (dir)
+  "Retrieve the top-level directory of a git tree."
+  (let ((cdup (with-output-to-string
+                (with-current-buffer standard-output
+                  (cd dir)
+                  (unless (eq 0 (call-process "git" nil t nil
+                                              "rev-parse" "--show-cdup"))
+                    (error "cannot find top-level git tree for %s." dir))))))
+    (expand-file-name (concat (file-name-as-directory dir)
+                              (car (split-string cdup "\n"))))))
+
 (defun switch-to-stgit-buffer (dir)
   "Switch to a (possibly new) buffer displaying StGit patches for DIR"
   (setq dir (file-name-as-directory dir))