commit fb93352c64348424a9a37225f298a36507bf170b
Author: Phil Jackson <phil@shellarchive.co.uk>
Date:   Mon Dec 7 18:07:57 2009 +0000

    Commit buffer will fill if the commit is current and the buffer dead.

diff --git a/magit.el b/magit.el
index 5d8352c..e171d73 100644
--- a/magit.el
+++ b/magit.el
@@ -1957,7 +1957,10 @@ string which will represent the log line.")
     (setq commit (magit-section-info commit)))
   (let ((dir default-directory)
 	(buf (get-buffer-create "*magit-commit*")))
-    (cond ((equal magit-currently-shown-commit commit)
+    (cond ((and (equal magit-currently-shown-commit commit)
+		;; if it's empty then the buffer was killed
+		(with-current-buffer buf
+		  (> (length (buffer-string)) 1)))
 	   (let ((win (get-buffer-window buf)))
 	     (cond ((not win)
 		    (display-buffer buf))